Tilburg University
Safety in numbers
Mesman, R.
Publication date: 2017 Document VersionPublisher's PDF, also known as Version of record
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Citation for published version (APA):
Mesman, R. (2017). Safety in numbers: Surgical volume as a quality measure. DekoVerdivas.
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SAFETY IN NUMBERS:
SURGICAL VOLUME
AS A QUALITY MEASURE
Safety in numbers Auteur: Roos Mesman
Ontwerp cover en uitnodiging: Gerard Vogelaar Vormgeving en drukwerk: DekoVerdivas ISBN/EAN: 978-90-9030493-9
@2017 Roos Mesman
Safety in numbers:
surgical volume as a quality measure
Proefschrift
ter verkrijging van de graad van doctor aan Tilburg University
RSJH]DJYDQGHUHFWRUPDJQL¿FXV SURIGU(+/$DUWV
in het openbaar te verdedigen ten overstaan van een door het college voor promoties aangewezen commissie
in de aula van de Universiteit
op vrijdag 13 oktober 2017 om 14.00 uur
Inhoud
CHAPTER 1 General introduction ... 7
CHAPTER 2 Evaluation of minimum volume standards for surgery in the Netherlands (2003-2017): a successful policy? ...21
CHAPTER 3 Volume standards: quality through quantity? relationship between treatment volume and outcomes not well founded. ...57
CHAPTER 4 Why do high-volume hospitals achieve better outcomes? A systematic review about intermediate factors in volume-outcome relationships. ...69
CHAPTER 5 Dutch surgeons’ views on the volume-outcome mechanism in surgery: a qualitative interview study. ... 101
CHAPTER 6 Exploring Dutch surgeons’ views on volume-based policies: a qualitative interview study. ... 117
CHAPTER 7 General discussion ... 135
Summary ... 169
Samenvatting ... 177
Dankwoord ... 187
Background
Improving quality of care is a continuous effort for health care professionals and policy makers in health systems worldwide. Despite a wealth of NQRZOHGJH H[SHULHQFH DQG EHVW SUDFWLFHV WKDW KDYH DFFXPXODWHG RYHU WKH ODVW GHFDGHV NQRZLQJ ZKLFK VWUDWHJLHV DUH EHQH¿FLDO IRU SDWLHQWV LV FKDOOHQJLQJ ,Q PHGLFDO FDUH DQG HVSHFLDOO\ VXUJLFDO FDUH FRPSOLFDWLRQV have become a major cause of death and disability worldwide.1 The
intuitively attractive notions “more is better” and “practice makes perfect” have been explored in an effort to uncover potential tools for improved UHVXOWV $V D UHVXOW YROXPH KDV EHHQ D GRPLQDQW IDFWRU LQ GHEDWH DQG policies about surgical quality.
)RU D EHWWHU XQGHUVWDQGLQJRI WKLV WKHVLV LW LV LPSRUWDQW WR FKDUDFWHUL]H VRPHNH\FRQFHSWV$FFRUGLQJWRWKH:RUOG+HDOWK2UJDQL]DWLRQ :+2 quality in health care is “the extent to which health care services provided to individuals and patient populations improve desired health outcomes. In RUGHUWRDFKLHYHWKLVKHDOWKFDUHPXVWEHVDIHHIIHFWLYHWLPHO\HI¿FLHQW equitable and people-centred.”2,QWKLVWKHVLVDOOWKUHHGRPDLQVWRDVVHVV
TXDOLW\ RI FDUH DV LQWURGXFHG E\ 'RQDEHGLDQ DUH UHOHYDQW VWUXFWXUH process and outcomes.3 Structure refers to the context in which care is
GHOLYHUHG HJ VWDII LQIUDVWUXFWXUH 3URFHVV GHVFULEHV WKH WUDQVDFWLRQV between patients and providers throughout the delivery of healthcare HJGLDJQRVWLFVWHFKQLFDOFRPSHWHQFH 2XWFRPHVUHIHUWRWKHHIIHFWVRI KHDOWKFDUHRQWKHKHDOWKVWDWXVRISDWLHQWV HJPRUWDOLW\PRELOLW\
Empirical evidence
6LQFH WKH V D ODUJH ERG\ RI UHVHDUFK KDV IRFXVHG RQ LQYHVWLJDWLQJ the effects of healthcare provider volume on patient outcomes. Both short-term outcomes—such as operative mortality4-6OHQJWKRIVWD\DQG
cost7-11— as well as long-term outcomes—such as survival12-14— have been
VKRZQWRLPSURYHZLWKKLJKHUYROXPH(VSHFLDOO\LQKLJKULVNVXUJHU\VXFK DVHVRSKDJHFWRP\SDQFUHDWLFUHVHFWLRQDQGDEGRPLQDODRUWLFDQHXU\VP repair.15-17 9ROXPHRXWFRPH DVVRFLDWLRQV KDYH DOVR EHHQ FRQ¿UPHG LQ
various systematic reviews.19-21 The magnitude of the relationship varies
DQGVHHPVGHSHQGHQWRQ GLDJQRVLVRUW\SHRIVXUJHU\OHYHORIDQDO\VLV operationalization of quality and methodological choices.22 Although
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 very-low-birth-weight neonates26-27. Volume-based policy
Despite the lack of consistency in results and on-going debate about the PHWKRGRORJLFDO TXDOLW\ RI YROXPHRXWFRPH VWXGLHV WKH ¿QGLQJV KDYH LQÀXHQFHGFXUUHQWSROLF\LQLWLDWLYHVLQVHYHUDOFRXQWULHV28-37 These volume-based policies are aimed at steering patients away from low-volume providers to improve their odds of better outcomes after surgery. This can be achieved by enforcing minimum volume standards for surgical procedures. Low-volume providers with caseloads below these thresholds may not be eligible for a contract and/or risk other sanctions. Another VWUDWHJ\ LV FRQFHQWUDWLRQ RI VSHFL¿F VXUJHULHV LQ D OLPLWHG QXPEHU RI KRVSLWDOVZKLFKLVDOVRUHIHUUHGWRDVFHQWUDOL]DWLRQRUUHJLRQDOL]DWLRQ'XH WRWKHFRQFHQWUDWLRQRIFDUHLQWKHVHKRVSLWDOVWKH\EHFRPHKLJKYROXPH SURYLGHUVDQGDUHXVXDOO\FHQWHUVRIH[FHOOHQFHZLWKVSHFL¿FH[SHUWLVHDQG infrastructure.
Implications
3HUKDSV WKH PRVW FRPSHOOLQJ ZD\ WR LOOXVWUDWH WKH EHQH¿WV RI YROXPH based policies is calculating the number of lives that could be saved by referring patients to high-volume providers. Epstein et al. (2005) estimated 728 deaths could be avoided annually by adopting the Leapfrog Group’s recommended hospital procedure volume minimums for coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI).38 Birkmeyer et al. (1999) calculated the number of lives saved by
regionalization for ten high-risk surgical procedures. Their estimation ranged from 800 to 4300 deaths (5-25% mortality reduction).39 Another
study by Birkmeyer et al. (2001) estimated that nationwide implementation RI/HDSIURJYROXPHVWDQGDUGVIRU¿YHKLJKULVNVXUJLFDOSURFHGXUHVZRXOG SUHYHQWVXUJLFDOGHDWKVLQXUEDQDUHDV40 In a similar study a few \HDUVODWHU%LUNPH\HU 'LPLFN IRXQGWKDWIXOOLPSOHPHQWDWLRQRI the Leapfrog standards would have averted 7818 of surgical deaths: CABG 3&, HOHFWLYH DEGRPLQDO DRUWLF DQHXU\VP UHSDLU RHVRSKDJHDOUHVHFWLRQ DQGSDQFUHDWLFUHVHFWLRQ 41 Dudley et al. (2000) applied the best existing estimate of the volume-outcome effect IRUVHYHUDOSURFHGXUHVWRWKH&DOLIRUQLDSRSXODWLRQ,QWKHLUDQDO\VLVWKH\ concluded that more than 600 deaths in California and 4000 deaths in the United States could be averted yearly by selective referral to high-volume hospitals.42 Despite these estimations and other evidence for improvement
and side effects. One limitation is that patients may be faced with greater travel distances for specialist care. These increased travel distances can create barriers to timely and high-quality care for those without easy access and limited transportation. This could affect patients in rural areas DQGRUIURPDFHUWDLQVRFLRHFRQRPLFVWDWXVZKLFKPD\ZRUVHQH[LVWLQJ disparities between patients treated in high-volume and low-volume hospitals.43-50 A possible side effect of minimum volume standards are
SHUYHUVH LQFHQWLYHV WR LQFUHDVH YROXPH VXFK DV RSHUDWLQJ RQ SDWLHQWV who may not be considered as candidates for surgery.20,51 And loss of
procedure volume could also adversely affect a hospital’s or surgeon’s DELOLW\WRPDQDJHHPHUJHQWFDVHVDVZHOODVSUR¿FLHQF\LQUHODWHGHOHFWLYH procedures without volume standards.20,51 These low-volume centers may
IDFH FKDOOHQJHV LQ DWWUDFWLQJ RU PDLQWDLQLQJ TXDOL¿HG SURIHVVLRQDOV20 At
WKHVDPHWLPHFHQWUDOL]DWLRQKDVWKHSRWHQWLDOWRFDXVHFDSDFLW\LVVXHV in high-volume hospitals as they may struggle to accommodate extra patients without extra waiting times.50,52 These consequences warrant
VROLGHYLGHQFHRIWKHVWUHQJWKRIYROXPHDVDTXDOLW\LQGLFDWRU+RZHYHU there is wide consensus that volume is an imperfect correlate of quality; YROXPHDORQHGRHVQRWUHVXOWLQEHWWHUSHUIRUPDQFHEXWDFWVDVDSUR[\ measure for various processes and provider characteristics that directly LQÀXHQFHRXWFRPHV16,22,23,51,53 The international emphasis on volume as a
proxy for quality requires more knowledge about what volume is a proxy for.
Underlying mechanism of volume-outcome relationships
This thesis focuses on the underlying mechanism of volume-outcome relationships. Understanding the relationship between procedure volume DQGRXWFRPHVLVRIYLWDOLPSRUWDQFHERWKIRUDFDGHPLFUHVHDUFKDQGIRU health policy. Some authors have attempted to shed some light on the XQGHUO\LQJIDFWRUV,QWKLVUHJDUGWZRSULQFLSDOFRQFHSWXDOPRGHOVKDYH EHHQLQWURGXFHG)LUVW/XIWHWDO KDYHH[SORUHGWKHSODXVLELOLW\RI WZRDOWHUQDWLYHQRWPXWXDOO\H[FOXVLYHK\SRWKHVHVIRUWKHLQYHUVHYROXPH± outcome relationships: “selective referral” versus “practice-makes-perfect”.547KH¿UVWUHIHUVWRWKHQRWLRQWKDWDQREVHUYHGUHODWLRQVKLSPD\
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
RXWFRPH %RWK FDXVDO PRGHOV KDYH EHHQ WHVWHG IRU YDULRXV SURFHGXUHV with varying results.54-57 Luft et al. (1987) conducted both simple
cross-tabulations and a simultaneous econometric test to provide evidence for both explanations and for the fact that the plausibility of each explanation vary across diagnoses and procedures.54 Selective referrals were seen in
patient categories that are more complex and more likely to be treated by a specialist than by a primary care physician or general surgeon. Practice-makes-perfect results were found in patient categories that are less likely to be referred. Flood et al. (1984) examined the impact of treatment in a hospital with a high or low volume of similar patients. They found strong and consistent evidence that more practice (high-volume) leads to better outcomes.55 +RZHYHU+XHVFKHWDO ZHUHQRWDEOH
WR ¿QG HYLGHQFH LV IRU OHDUQLQJ E\ GRLQJ LQ FDUGLDF VXUJHU\56 Whereas
Tsai et al. (2006) examined whether volume-outcome effects may be contaminated by selective referrals and will therefore exaggerate the importance of practice makes perfect.57 They conclude that concentration
of congestive heart failure (CHF) may not reduce mortality among elderly SDWLHQWV$V/XIWHWDO SRLQWHGRXWLQDV\VWHPZKHUHSXUFKDVHUV DSSO\VHOHFWLYHFRQWUDFWLQJPRVWO\EDVHGRQSULFHERWKH[SODQDWLRQVKDYH different policy implications.54 :KHQ SUDFWLFH WUXO\ PDNHV SHUIHFW WKH
outcomes in selected hospitals will improve after concentration. Outcomes in hospitals that miss out on a contract may even eventually worsen. If VHOHFWLYHUHIHUUDOLVWKHGRPLQDQWIDFWRUVHOHFWLQJKRVSLWDOVEDVHGRQSULFH will not necessarily improve outcomes. High performing hospitals may be excluded. This illustrates the importance of a broad perspective on volume-outcome relationships and the underlying mechanisms. Authors of a comprehensive Dutch study (2012) recommend assessing volume-based initiatives from four standpoints: societal standpoint (i.e. quality RIFDUHDFFHVVLELOLW\¿QDQFHV HI¿FLHQF\ RUJDQLVDWLRQDOVWDQGSRLQW LH VWUDWHJLF PDUNHW SRVLWLRQ SURIHVVLRQDO VWDQGSRLQW LPSURYHPHQW LQ SURIHVVLRQDOTXDOLW\VWDI¿QJLVVXHV¿QDQFLDOJDLQV DQGSDWLHQWVWDQGSRLQW RSHUDWLRQDOL]DWLRQRITXDOLW\LPSURYHPHQWEDODQFHEHWZHHQFRQFHQWUDWLRQ DQG UHJLRQDO GLVWULEXWLRQ RI FDUH VROYLQJ QHZ SUREOHPV FDXVHG E\ WKH initiative).22 Their case studies (e.g. concentration of care) showed that
volume-based initiatives in the Netherlands were predominantly motivated by the organisational and professional standpoint. The societal and patient standpoints were mostly used for legitimizing purposes.
insights in volume-outcome research.58 Halm et al. (2000) criticizes the
theories posed by Luft for lacking robust empirical support and providing little explanation of how high volume may relate to better outcomes. First RI DOO UHVHDUFK KDV QRW EHHQ DEOH WR GHWHUPLQH ZKDW VNLOOV RU SUDFWLFHV improve with more experience and why they are uniquely related to volume. 6HFRQG WKH DXWKRUV TXHVWLRQ ZKHWKHU UHIHUULQJ SK\VLFLDQV DQG SDWLHQWV have access to and use performance data to enable “selective referral”. )LQDOO\ QHLWKHU WKHRU\ H[SODLQV WKH FDXVHV RI GLIIHUHQFHV LQ RXWFRPHV among providers with different volumes or how underperformance can be LPSURYHG%DVHGRQWKHVHVKRUWFRPLQJVDQGPRUHUHFHQWUHVHDUFK+DOPHW al. (2000) developed a new conceptual model displaying the factors which are likely to be the most potent explanatory variables in understanding KRZ YROXPH RI VHUYLFHV LV UHODWHG WR KHDOWK RXWFRPHV ¿JXUH 58 The
IDFWRUVLQFOXGHSDWLHQWVHOHFWLRQDQGSDWLHQWFKDUDFWHULVWLFVSK\VLFLDQDQG KRVSLWDOFKDUDFWHULVWLFVVXFKDVVNLOOVDQGDYDLODELOLW\RIFHUWDLQUHVRXUFHV Halm et al. (2000) also used their model to develop criteria for judging the methodological quality of published volume-outcome research.59-61
It emphasizes the need for assessing multiple factors when examining volume-outcome relationships. Mayer et al. (2009) used the framework WRVWUHVVWKHLPSRUWDQFHRIPXOWLOHYHOPRGHOOLQJZKLFKWDNHVLQWRDFFRXQW that patients are “nested” within surgeons and surgeons are “nested” within institutions.59
Figure 1
Conceptual framework by Halm et al.: How could volume affect quality?58
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Conceptual framework and research questions
Halm et al. (2000) criticized Luft’s hypotheses for lacking robust empirical VXSSRUW+RZHYHUWKHIDFWRUVLQWKHLURZQPRGHODUHDOVRPRVWO\EDVHGRQ intuition rather than robust evidence. As the authors state in the publication in which they introduce their model: “(..) displays the factors we believe are likely to be the most potent explanatory variables in understanding how volume of services is related to health outcomes”.58 When describing
Figure 2
Conceptual framework in this thesis
The main objective of this thesis is to generate knowledge about the circumstances under which volume and outcome show a positive DVVRFLDWLRQ LQ RWKHU ZRUGV XQUDYHOOLQJ WKH ZRUNLQJ PHFKDQLVPV ,W is focused on evaluating the rationale of volume-based policies such as minimum volume standards and concentration of care. A better understanding of the mechanisms underlying the observed associations between volume and outcome can provide opportunities for improving quality of care in both high- and low-volume settings.
7KHVSHFL¿FUHVHDUFKTXHVWLRQVDUHDVIROORZV
1. How were minimum volume standards introduced in the Netherlands and what have been the implications?
2. What empirical evidence on volume-outcome relationships in medical care is available and how can it be assessed?
3. What factors are important in volume-outcome relationships according to Dutch surgeons?
4. What are Dutch surgeons’ experiences with the implementation and implications of volume-based policies?
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Thesis outline
The thesis starts with an evaluation of volume-based policies in the Netherlands in Chapter 2. This chapter provides an overview of how minimum volume standards were introduced and enforced in Dutch context. The implications and lessons for other health care systems are also discussed.
Chapter 3IRFXVHVRQWKHUDWLRQDOHEHKLQGPLQLPXPYROXPHVWDQGDUGV the underlying peer-reviewed literature and its limitations.
In Chapter 4 a systematic review of peer-reviewed literature on the role of process and structural factors in volume-outcome relationships is presented. Possible explanatory factors as well as an appraisal of methodological quality of available studies are described in this review. Chapter 5 explores Dutch surgeons’ views on volume-outcome relationships and the underlying mechanisms. This chapter presents the ¿QGLQJVRIDTXDOLWDWLYHVWXG\LQZKLFK'XWFKVXUJHRQVZHUHLQWHUYLHZHG Chapter 6 focuses on Dutch surgeons’ views on volume-based policies in the Netherlands. This paper gives insight into the impact of volume-based policies in Dutch hospitals from a surgeons’ perspective.
/DVWO\ LQ Chapter 7 WKH PDLQ ¿QGLQJV RI WKLV WKHVLV DUH SUHVHQWHG DV ZHOO DV WKH PHWKRGRORJLFDO FRQVLGHUDWLRQV WKH LPSOLFDWLRQV DQG recommendations for future research.
References
1. World health organization. WHO Guidelines for Safe Surgery 2009. Safe Surgery Saves Lives. Geneva. 2009. Available at: http://www.who.int/ patientsafety/safesurgery/tools_resources/9789241598552/en/
2. World health organization. What is Quality of Care and why is it important? Available at: http://www.who.int/maternal_child_adolescent/topics/ TXDOLW\RIFDUHGH¿QLWLRQHQ
3. Donabedian A. Evaluating the quality of medical care. Milbank Mem Fund Q. 1966;44:166-206.
of hospital procedure volume on outcomes following surgery for colon cancer. JAMA 2000 284:3028-35.
%LUNPH\HU-'6WXNHO7$6LHZHUV$(*RRGQH\33:HQQEHUJ'(/XFDV FL. Surgeon volume and operative mortality in the United States. N Engl J Med 2003 349(22):2117-27.
'LPLFN -% 8SFKXUFK *5 -U (QGRYDVFXODU WHFKQRORJ\ KRVSLWDO YROXPH and mortality with abdominal aortic aneurysm surgery. J Vasc Surg 2008 47(6):1150-4.
+DUPRQ -: 7DQJ '* *RUGRQ 7$ HW DO +RVSLWDO YROXPH FDQ VHUYH DV a surrogate for surgeon volume for achieving excellent outcomes in colorectal resection. Ann Surg 1999 230:404-13.
9RJHO 75 'RPEURYVNL\ 9< *UDKDP $0 &DURWLG DUWHU\ VWHQWLQJ LQ WKH QDWLRQ WKHLQÀXHQFHRIKRVSLWDODQGSK\VLFLDQYROXPHRQRXWFRPHV9DVF Endovascular Surg 2010 44(2):89-94.
&KLX && :DQJ -- 7VDL 7& &KX && 6KL +< 7KH 5HODWLRQVKLS EHWZHHQ Volume and Outcome after Bariatric Surgery: A Nationwide Study in Taiwan. Obes Surg 2012 22(7):1008-15.
$O4XUD\VKL = 5RELQV 5 +DXFK $ 5DQGROSK *: .DQGLO ( $VVRFLDWLRQ of Surgeon Volume With Outcomes and Cost Savings Following Thyroidectomy: A National Forecast. JAMA Otolaryngol Head Neck Surg 2015 12:1-8.
%DVTXHV %$ %LWWHUPDQ $ &DPSEHOO .- +DXJKRP %' /LQ - /HH 6 ,QÀXHQFH RI 6XUJHRQ 9ROXPH RQ ,QSDWLHQW &RPSOLFDWLRQV &RVW DQG Length of Stay Following Total Ankle Arthroplasty. Foot Ankle Int 2016 37(10):1046-51.
%DFK3%&UDPHU/'6FKUDJ''RZQH\5-*HOIDQG6(%HJJ&%7KH LQÀXHQFHRIKRVSLWDOYROXPHRQVXUYLYDODIWHUUHVHFWLRQIRUOXQJFDQFHU1 Engl J Med 2001 345(3):181-8.
$O6DKDI0/LP(7KHDVVRFLDWLRQEHWZHHQVXUJLFDOYROXPHVXUYLYDODQG quality of care. J Thorac Dis 2015 7(Suppl 2):S152-5.
%LUNPH\HU -' 6XQ < :RQJ 6/ 6WXNHO 7$ +RVSLWDO YROXPH DQG ODWH survival after cancer surgery. Ann Surg 2007 245(5):777-83.
'LPLFN -% 3URQRYRVW 3- &RZDQ -$ /LSVHWW 3$ 6XUJLFDO YROXPH DQG quality of care for esophageal resection: do high-volume hospitals have fewer complications? Ann Thorac Surg. 2003 75(2):337-41.
%LUNPH\HU-'6LHZHUV$()LQOD\VRQ(96WXNHO7$/XFDV)/%DWLVWD, :HOFK+*:HQQEHUJ'(+RVSLWDOYROXPHDQGVXUJLFDOPRUWDOLW\LQWKH 8QLWHG6WDWHV1(QJO-0HG ±
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 ±
5RXYHODV , /DJHUJUHQ - 7KH LPSDFW RI YROXPH RQ RXWFRPHV DIWHU oesophageal cancer surgery. ANZ J Surg 2010 80(9):634-41.
$UFKDPSRQJ'%RURZVNL':LOOH-¡UJHQVHQ3,YHUVHQ/+:RUNORDGDQG surgeon´s specialty for outcome after colorectal cancer surgery (Review). 7KH&RFKUDQH&ROODERUDWLRQ3XEOLVKHGE\-RKQ:LOH\ 6RQV/WG 1XWWDOO0YDQGHU0HXOHQ-3KLOOLSV16KDUSLQ&*LOODWW'0F,QWRVK*
Emberton M. A systematic review and critique of the literature relating hospital or surgeon volume to health outcomes for 3 urological cancer procedures. J Urol. 2004 172(6 Pt 1):2145-52.
7RO -$ YDQ *XOLN 70 %XVFK 25 *RXPD '- &HQWUDOL]DWLRQ RI KLJKO\ complex low-volume procedures in upper gastrointestinal surgery. A summary of systematic reviews and meta-analyses. Dig Surg 2012 29(5):374-83.
=XLGHUHQW-HUDN 7 .RRO 7 5DGHPDNHUV - 'H UHODWLH WXVVHQ YROXPH HQ kwaliteit van zorg. Tijd voor een brede benadering. Utrecht/Nijmegen/ 5RWWHUGDP &RQVRUWLXP2QGHU]RHN.ZDOLWHLWYDQ=RUJ
23. Hellinger F. Practice makes perfect: a volume-outcome study of hospital SDWLHQWVZLWK+,9GLVHDVH-$FTXLU,PPXQH'H¿F6\QGU 33.
:LOODUG &/ /LOMHVWUDQG 3 *ROGVFKPLGW 5+ *UXPEDFK . ,V H[SHULHQFH ZLWKKXPDQLPPXQRGH¿FLHQF\YLUXVGLVHDVHUHODWHGWRFOLQLFDOSUDFWLFH"$ survey of rural primary care physicians. Arch Fam Med. 1999;8(6):502-GLVFXVVLRQ
3LHSHU ' 0DWKHV 7 0DUVKDOO 05 $ V\VWHPDWLF UHYLHZ RI WKH LPSDFW RI center volume in dialysis. MC Res Notes. 2015;8:812.
&KXQJ-+3KLEEV&6%RVFDUGLQ:-.RPLQVNL*)2UWHJD$1*UHJRU\.' Needleman J. Examining the effect of hospital-level factors on mortality of very low birth weight infants using multilevel modeling. J Perinatol. 2011;31(12):770-5.
&KXQJ-+3KLEEV&6%RVFDUGLQ:-.RPLQVNL*)2UWHJD$11HHGOHPDQ J. The effect of neonatal intensive care level and hospital volume on mortality of very low birth weight infants. Med Care. 2010;48(7):635-44. +DOP ($ /HH & &KDVVLQ 05 ,V YROXPH UHODWHG WR RXWFRPH LQ KHDOWK care? A systematic review and methodologic critique of the literature. $QQ,QWHUQ0HG ±
+HQQHPDQ''LNNHQ-/3XWWHU+/HPPHQV9(9DQGHU*HHVW/*YDQ +LOOHJHUVEHUJ5HWDO&HQWUDOL]DWLRQRIHVRSKDJHFWRP\ KRZIDUVKRXOG we go? Ann Surg Oncol 2014 21:4068-74.
et al. Is It Time to Centralize High-risk Cancer Care in the United States? Comparison of Outcomes of Esophagectomy Between England and the United States. Ann Surg 2015 262:79-85.
&UDZIRUG 5 *UHHQEHUJ ' ,PSURYHPHQWV LQ VXUYLYDO RI J\QDHFRORJLFDO cancer in the Anglia region of England: are these an effect of centralisation RIFDUHDQGXVHRIPXOWLGLVFLSOLQDU\PDQDJHPHQW"%-2* ± 5.
0D\HU(.%RWWOH$'DU]L$:$WKDQDVLRX79DOH-$7KHYROXPHPRUWDOLW\ relation radical cystectomy in England: retrospective analysis of hospital episode statistics. BMJ 2010 340:c1128.
:HHNV:%9HQWHORX%2U=:LWKRXW([SOLFLW7DUJHWV'RHV)UDQFH0HHW 0LQLPXP9ROXPH7KUHVKROGVIRU+LSDQG.QHH5HSODFHPHQWDQG%DULDWULF Surgeries? Int J Health Policy Manag 2016 5:613-4.
5RFRFR ( 0D]RXQL & 2U = 0RELOOLRQ 9 .RRQ 6XQ 3DW 0 %RQDVWUH - Variation in rates of breast cancer surgery: A national analysis based on French Hospital Episode Statistics. Eur J Surg Oncol 2016 42:51-8. GH &UXSSp : 2KPDQQ & %OXP . *HUDHGWV 0 (YDOXDWLQJ FRPSXOVRU\
minimum volume standards in Germany: how many hospitals were compliant in 2004? BMC Health Serv Res 2007 17:165.
GH&UXSSp:0DOLN0*HUDHGWV00LQLPXPYROXPHVWDQGDUGVLQ*HUPDQ hospitals: do they get along with procedure centralization? A retrospective longitudinal data analysis. BMC Health Serv Res 2015 22:279.
%DURQH-(7XFNHU-%%XOO607KH/HDSIURJ,QLWLDWLYH DSRWHQWLDOWKUHDW to surgical education. Curr Surg 2003 60:218-21.
(SVWHLQ$-5DWKRUH66.UXPKRO]+09ROSS.*9ROXPHEDVHGUHIHUUDO for cardiovascular procedures in the United States: a cross-sectional regression analysis. BMC Health Serv Res 2005 5(3):42.
%LUNPH\HU-'/XFDV)/:HQQEHUJ'(3RWHQWLDOEHQH¿WVRIUHJLRQDOL]LQJ major surgery in medicare patients. Eff Clin Pract 1999 2:277-283. %LUNPH\HU-')LQOD\VRQ(9%LUNPH\HU&09ROXPHVWDQGDUGVIRUKLJK
ULVN VXUJLFDO SURFHGXUHV SRWHQWLDO EHQH¿WV RI WKH /HDSIURJ LQLWLDWLYH 6XUJHU\ ±
%LUNPH\HU-''LPLFN-%3RWHQWLDOEHQH¿WVRIWKHQHZ/HDSIURJVWDQGDUGV effect of process and outcomes measures. Surgery 2004 135(6):569-75. 'XGOH\5$-RKDQVHQ./%UDQG55HQQLH'-0LOVWHLQ$6HOHFWLYHUHIHUUDO
to high-volume hospitals: estimating potentially avoidable deaths. JAMA 2000 283(9):1159-66.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 6NRODUXV7$&KDQ66KHOWRQ-%$QWRQLR$/6DOHV$(0DOLQ-/6DLJDO CS. Quality of prostate cancer care among rural men in the Veterans Health Administration. Cancer. 2013 119(20):3629-35.
0HKDIIH\-+0LFKDHOV$'0XOOHQ0*0HQHYHDX023HQGHU-5+DOORZHOO PT. Patient travel for bariatric surgery: does distance matter? Surg Obes Relat Dis. Dec 28. pii: S1550-7289(16)30889-9. doi: 10.1016/j. soard.2016.12.025. [Epub ahead of print]
$QGHUVRQ &% *HQQDUHOOL 5 +HUU +: (ONLQ (% 5HJLRQDOL]DWLRQ RI radical cystectomy in the United States. Urol Oncol. 2017 pii: S1078-1439(17)30135-7. doi: 10.1016/j.urolonc.2017.03.026. [Epub ahead of print]
%LUNPH\HU -' 6LHZHUV $( 0DUWK 1- *RRGPDQ '& 5HJLRQDOL]DWLRQ RI high-risk surgery and implications for patient travel times. JAMA. 2003 26;290(20):2703-8.
6SHLFKHU3-(QJOXP%5*DQDSDWKL$0:DQJ;+DUWZLJ0*'¶$PLFR 7$ %HUU\ 0) 7UDYHOLQJ WR D +LJKYROXPH &HQWHU LV $VVRFLDWHG :LWK Improved Survival for Patients With Esophageal Cancer. Ann Surg. 2017 265(4):743-749.
:DUG 00 -DDQD 0 :DNH¿HOG '6 2KVIHOGW 5/ 6FKQHLGHU -( 0LOOHU 7 /HL<:KDWZRXOGEHWKHHIIHFWRIUHIHUUDOWRKLJKYROXPHKRVSLWDOVLQD largely rural state? J Rural Health 2004 20(4):344-54.
6WLW]HQEHUJ .% 6LJXUGVRQ (5 (JOHVWRQ %/ 6WDUNH\ 5% 0HURSRO 1- Centralization of cancer surgery: implications for patient access to optimal care. J Clin Oncol. 2009 27(28):4671-8.
+HZLWW 0 3HWLWWL ' ,QWHUSUHWLQJ WKH YROXPH±RXWFRPH UHODWLRQVKLS LQ WKH FRQWH[W RI FDQFHU FDUH 1DWLRQDO &DQFHU 3ROLF\ %RDUG ,QVWLWXWH RI 0HGLFLQH DQG 1DWLRQDO 5HVHDUFK &RXQFLO :DVKLQJWRQ '& 1DWLRQDO Academy Press; 2001.
5DYDO09%LOLPRULD.<7DODPRQWL064XDOLW\LPSURYHPHQWIRUSDQFUHDWLF cancer care: is regionalization a feasible and effective mechanism? Surg Oncol Clin N Am. 2010 19(2):371-90.
)LQOD\VRQ 65* 7KH YROXPH±RXWFRPH GHEDWH UHYLVLWHG 7KH $PHULFDQ -RXUQDORI6XUJHU\ ±
/XIW+6+XQW660DHUNL6&7KHYROXPH±RXWFRPHUHODWLRQVKLS SUDFWLFH makes perfect or selective-referral patterns? Health Serv Res 1987 ±
)ORRG$%6FRWW:5(Z\:'RHVSUDFWLFHPDNHSHUIHFW", 7KHUHODWLRQ between hospital volume and outcomes for selected diagnostic categories. Medical Care 1984 22:98-114.
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+DOP($/HH&&KDVVLQ05+RZLVYROXPHUHODWHGWRTXDOLW\LQKHDOWK care? A systematic review of the research literature. In: Interpreting WKHYROXPH±RXWFRPHUHODWLRQVKLSLQWKHFRQWH[WRIKHDOWKFDUHTXDOLW\ ZRUNVKRSVXPPDU\:DVKLQJWRQ'& ,QVWLWXWHRI0HGLFLQH 0D\HU (. 3XUND\DVWKD 6 $WKDQDVLRX 7 'DU]L $ 9DOH -$ $VVHVVLQJ
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
CHAPTER 2
Evaluation of minimum volume standards
for surgery in the Netherlands (2003-2017):
a successful policy?
5RRV0HVPDQ0DUMDQ-)DEHU%DUW--0%HUGHQ*HUW3:HVWHUW
Evaluation of minimum volume standards for surgery in the Netherlands (2003-2017): a successful policy?
Abstract
Purpose: To evaluate the introduction and implications of minimum volume standards for surgery in Dutch health care from 2003 to 2017 and formulate policy lessons for other countries.
Setting: Dutch health care.
3ULQFLSDO¿QGLQJV 7KUHHHUDVZHUHLGHQWL¿HGUHSUHVHQWLQJDWUXVWDQG control cycle in keeping with changing roles of different stakeholders in 'XWFK FRQWH[W ,Q WKH ¿UVW HUD µUHJXODWHG WUXVW¶ WKH 'XWFK Inspectorate introduced national volume criteria and relied on yearly hospital reported data for information on compliance. In the second era ¶FRQWUDFWDQGFRQWURO¶ WKHHIIHFWVRIPDUNHWRULHQWHGUHIRUP became more evident. The Dutch government intervened in the market and health insurers introduced selective contracting. Medical professionals ZHUH SURPSWHG WR UHFODLP WKH LQLWLDWLYH ,Q WKH FXUUHQW HUD D return of trust in self-regulation seems visible. The number of low- volume hospitals performing complex surgeries in the Netherlands has decreased and research has shown improved outcomes as a result.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Introduction
Improving patient safety in high-risk care such as surgery has been a priority in many countries.1,26LQFHWKH VLQWHUQDWLRQDOSHHUUHYLHZHG
VWXGLHVLGHQWL¿HGFDVHYROXPHDVDQLPSRUWDQWLQÀXHQWLDOIDFWRUIRUEHWWHU outcomes after surgery. Especially in high-risk surgery such as oesophageal resections and abdominal aortic surgery.3-22$VLQPDQ\RWKHUFRXQWULHV
these insights have been transferred into volume-based policy in the Netherlands. This policy is aimed at directing certain surgical procedures away from low-volume providers in an effort to reduce patients’ risks RI DGYHUVH RXWFRPHV )RU WKLV SXUSRVH JRYHUQPHQW ERGLHV DQG SD\HUV (health insurers) enforce minimum volume standards. Although no health FDUH V\VWHP LV DOLNH WKH 'XWFK FRQWH[W RIIHUV DQ LQWHUHVWLQJ VHWWLQJ WR evaluate the use of minimum volume standards over a 14-year period (2003-2017). The aim of this evaluation is to gain insight into minimum volume standards in the Dutch Health care system and to formulate policy lessons for other countries. We set out to answer the following research questions: How were minimum volume standards introduced in the Netherlands? What have been their implications? What lessons can be learned from Dutch experiences?
)RUDEHWWHUXQGHUVWDQGLQJRQWKHFRQWH[WRIWKLVSDSHUVRPHEDFNJURXQG information on Dutch health care is required. Since the Second World :DUWKHUROHRIWKH'XWFKJRYHUQPHQWZDVIRFXVHGRQGLUHFWFRQWURORI YROXPHVSULFHVDQGSURGXFWLYHFDSDFLW\23,QDQHZ+HDOWK,QVXUDQFH
$FWFDPHLQWRHIIHFWDQGVLJQL¿HGDIXQGDPHQWDOUHIRUPLQ'XWFKKHDOWK care.24,25 The system of public and private insurance was abolished and
replaced by managed competition for providers and insurers. The new V\VWHPLQWURGXFHGWKUHHPDUNHWV KHDOWKFDUHSURYLVLRQKHDOWKLQVXUDQFH and the purchasing of health care. The government switched from steering the system to safeguarding the proper functioning of these new PDUNHWV 7KH 'XWFK +HDOWKFDUH $XWKRULW\ 1HGHUODQGVH =RUJDXWRULWHLW NZa) was established for this task and oversees the lawful implementation of the Health Insurance Act by all stakeholders.23,26 ,Q DGGLWLRQ WKH 7KH
Netherlands Authority for Consumers and Markets (ACM) supervises health LQVXUHUV DQG KHDOWK FDUH SURYLGHUV DV WKHVH DUH VXEMHFW WR WKH 'XWFK Competition Act (Mededingingswet).23 ACM can track down and enforce
+HDOWKLQVXUHUVSOD\DFHQWUDOUROHDVSUXGHQWSXUFKDVHUVRIKHDOWKFDUH aiming for more value for money.24 )RU WKLV WDVN KHDOWK FDUH LQVXUHUV
can apply selective contracting of care (e.g. hospital care).23-25 Quality
LQGLFDWRUVDUHLQFRUSRUDWHGLQWKHLUSXUFKDVLQJFULWHULDLQFOXGLQJYROXPH WKUHVKROGV+RZHYHUDIWHUPRUHWKDQDGHFDGHVLQFHWKHUHIRUPVHOHFWLYH purchasing based on quality is still very limited.27,Q¿JXUHWKHDFWRUV
DQG PDUNHWV LQ 'XWFK KHDOWK FDUH DUH VKRZQ DV ZHOO DV KRZ YROXPH based initiatives play out on each market.
Figure 1
Actors and markets in the Dutch Health Care system and volume standards
(adapted from Schäfer et al.)23
'HVSLWH LQFUHDVHG PDUNHW LQFHQWLYHV WKH 'XWFK JRYHUQPHQW PDLQWDLQV the formal responsibility for the supervision and monitoring of the quality of the care delivered by both public and private providers.28 The Dutch
Health Care Inspectorate (IGZ) was founded in 1995 as a main advisory ERG\WRWKH0LQLVWHURI+HDOWK:HOIDUHDQG6SRUWDQGLVUHVSRQVLEOHIRU ,QVXUHG SDWLHQWV 3URYLGHUV ,QVXUHUV Health insurance market Health care purchasing market Health care provision market
Dutch Healthcare Authority (Nederlandse Zorgautoriteit, NZa) and The Netherlands Authority for Consumers and
Markets (Autoriteit Consument en Markt)
Selective purchasing based on price, volume
and quality criteria, including minimum volume standards Health insurers compete
for LQVXUHG on quality of care and price. They can distinguish themselves from their competitors through selective purchasing, for instance based on volume criteria
Patients can choose their health care provider based on information provided by the government on the Internet, including
volume criteria
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
regulating quality of care provided by public and private providers.23,28-29
,Q WKH ,QVSHFWRUDWH LQWURGXFHG D VHW RI +RVSLWDO 3HUIRUPDQFH Indicators which were both obligatory and public.28 This provided them
with yearly data on the actual performance of every Dutch hospital. 'HVSLWH JRYHUQPHQWDO UHJXODWLRQV RQ SXEOLF KHDOWK DQG TXDOLW\ RI FDUH self-regulation has traditionally been an important characteristic of the Dutch health care system.23 Medical professionals are united in national
SURIHVVLRQDO DVVRFLDWLRQV ZKLFK GHIHQG WKH LQWHUHVWV RI WKHLU VSHFL¿F JURXS RI PHGLFDO VSHFLDOLVWV DQG IDFLOLWDWH VFLHQWL¿F DQG SURIHVVLRQDO GHYHORSPHQW)RULQVWDQFHSURIHVVLRQDODVVRFLDWLRQVPDLQWDLQWKHLURZQ UHUHJLVWUDWLRQ VFKHPHV DQG GHYHORS SURIHVVLRQDO JXLGHOLQHV 7KHUHIRUH the Inspectorate highlights “working on the basis of trust in care providers’ LQWULQVLFPRWLYDWLRQWRRIIHUWKHEHVWSRVVLEOHFDUH +RZHYHUZHVKDOO not hesitate to impose strict enforcement measures if a care provider GLVSOD\V UHFNOHVV EHKDYLRXU IDLOV WR OHDUQ IURP PLVWDNHV RU EUHDNV WKH law”.29,30
Materials and methods
Data sources and searches
7RDQVZHURXUUHVHDUFKTXHVWLRQVZHXVHGPXOWLSOHGDWDVRXUFHV)LUVWO\ we consulted research papers and Dutch policy reports to reconstruct important moments in the introduction and enforcement of minimum volume standards in the Netherlands. We focused on publications from the PDLQVWDNHKROGHUV PHGLFDODVVRFLDWLRQVKHDOWKLQVXUHUVDQGJRYHUQPHQW agencies such as the Inspectorate) and mainstream online health care QHZV ZHEVLWHV 6HFRQG ZH REWDLQHG KRVSLWDO UHSRUWHG GDWD RQ VXUJLFDO volume of all Dutch hospitals from the Dutch Hospital Database (2003-2016) and assessed yearly Inspectorate reports to assess trends and new developments in volume criteria (2003-2015).
7KLVVHDUFKLGHQWL¿HGWLWOHVRIZKLFKUHPDLQHGDIWHUVFUHHQLQJRI DEVWUDFWVE\DSSO\LQJWKHIROORZLQJLQFOXVLRQFULWHULD VXSSOHPHQWDU\¿OH • Effects of centralization of care in Dutch hospitals on patient outcomes
DUHDVVHVVHG
• 5HVXOWVPXVWEHEDVHGRQHPSLULFDOGDWD
• 3XEOLVKHGLQ(QJOLVKQRUHVWULFWLRQVIRU\HDURISXEOLFDWLRQ • Full-text paper must be available for the researchers.
Results
)URP RXU DQDO\VHV WKUHH HUDV ZHUH LGHQWL¿HG GXULQJ WKH LQWURGXFWLRQ and enforcement of minimum volume standards. We start our overview LQEHFDXVHYROXPHLQGLFDWRUVZHUHLQWURGXFHGIRUWKH¿UVWWLPHLQ WKDW \HDU E\ WKH ,QVSHFWRUDWH 7KH ¿UVW HUD HQGV LQ PDUNLQJ WKH beginning of increased government intervention and selective contracting E\KHDOWKLQVXUHUV7KHVHFRQGHUDHQGVLQLQGLFDWLQJWKHHQGRIWKH HPSKDVLVRQµFRQWUDFWVDQGFRQWURO¶DSSDUHQWLQSROLF\FKDQJHVPDGHE\ WKH,QVSHFWRUDWHDQGKHDOWKLQVXUHUV,QWKHWKLUGHUDSURIHVVLRQDOVUHJDLQ WKHLUOHDGLQJUROHLQHVWDEOLVKLQJTXDOLW\PHDVXUHV*LYHQWKHVHPLOHVWRQHV WKHWKUHHHUDVFDQEHODEHOOHGDVµUHJXODWHGWUXVW¶ µFRQWUDFW DQGFRQWURO¶ µUHWXUQRIWUXVW¶
Introduction and enforcement of minimum volume
standards
Regulated trust (2003-2009)
,Q 7KH+HDOWK&RXQFLORIWKH1HWKHUODQGVDQLQGHSHQGHQWVFLHQWL¿F DGYLVRU\ ERG\ IRU JRYHUQPHQW DQG SDUOLDPHQW SXEOLVKHG DQ LQÀXHQWLDO report on quality and distribution of cancer care.31 It triggered nationwide
DJUHHPHQWVRQFRQFHQWUDWLRQRIFRPSOH[FDUHIRULQVWDQFHIRUKHPDWRORJ\ head and neck oncology and sarcoma.32 Collective efforts for centralization
and consensus on minimum volume standards took longer for other surgical SURFHGXUHV)RUSDQFUHDWLFUHVHFWLRQVD\HDUSOHDIRUFHQWUDOL]DWLRQLQ the surgical community did not result in a change in the referral pattern and reduction of the mortality rate.33 Although professional associations
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
introduced by the Inspectorate in 2003.28 This marked the beginning
of volume standards as a quality measure in the Netherlands in which three stakeholders have alternated in taking the lead: Dutch government ,QVSHFWRUDWH PHGLFDOSURIHVVLRQDOVDQGKHDOWKLQVXUHUV
:KHQ WKH ,QVSHFWRUDWH LQWURGXFHG WKH ¿UVW PDQGDWRU\ VHW RI SXEOLF SHUIRUPDQFH LQGLFDWRUV LQ WZR YROXPH LQGLFDWRUV RI KLJKULVN interventions were included: volume of repairs of unruptured abdominal aortic aneurysm and volume of resections for oesophageal carcinoma.28
The Dutch Inspectorate made the following statement about the inclusion of YROXPHFULWHULD ³3UDFWLFHPDNHVSHUIHFWRUDWOHDVWOHDGVWRH[SHUWLVH:LWK every action in general and especially for technically complex actions such DVDEGRPLQDODRUWLFDQHXU\VPUHVHFWLRQVLWLVFOHDUWKDWPRUHH[SHULHQFH with the procedure leads to lower risk of complications. This applies to the VXUJHRQEXWDOVRWRWKHZKROHVXUJLFDOWHDPWKHDQHVWKHVLRORJLVWDQGWKH doctors and nurses on the Intensive Care Unit or ward”.34
7R PLQLPL]H WKH DGPLQLVWUDWLYH EXUGHQ YROXPH FULWHULD LQ WKH KRVSLWDO SHUIRUPDQFHLQGLFDWRUVHWDUHQRWUHSRUWHGRQDWHDPOHYHOEXWRQWKHOHYHO of the hospital location where the surgery is performed. Requiring hospitals to report on the number of high-risk operations they performed had so far been unheard of in the Netherlands.28 +RZHYHUWKLVQHZDSSURDFK³ZDV
DQLVVXHWKDWPDQ\IHOWZDVRYHUGXH´EHFDXVHRIWKHLQFUHDVLQJVFLHQWL¿F evidence for volume-outcome relationships for several high-risk surgical procedures. These early publications had prompted discussions in Dutch national surgical meetings as early as 1996.35
The performance indicator set is not “a set of control panels” for the Dutch Inspectorate. Scores are treated as signals that may trigger additional questions and/or investigations.28 If further investigation and dialogue
UHYHDO D IDLOXUH WR GHOLYHU TXDOLW\ RI FDUH WKH ,QVSHFWRUDWH FDQ HQIRUFH VDQFWLRQV ,Q WKH ,QVSHFWRUDWH IRUFHG KRVSLWDOV WKDW SHUIRUPHG less than 10 oesophageal resections in the last three consecutive years to stop providing these procedures unless they could provide concrete evidence for collaboration with other hospitals.36 This measure increased
E\ WKH ,QVSHFWRUDWH XOWLPDWHO\ VKRZHG VLJQL¿FDQW GLIIHUHQFHV EHWZHHQ the reported and actual number of oesophageal resections after the introduction of the new guidelines and enforcement of the minimum YROXPHVWDQGDUG2IWKHKRVSLWDOVVWXGLHGDFWXDOO\SHUIRUPHGIHZHU resections than they reported.
Volume thresholds for abdominal aortic procedures presented different FKDOOHQJHV ,Q WKHLU DQQXDO UHSRUW RQ KRVSLWDO LQGLFDWRUV WKH Inspectorate made an addition to the aforementioned statement about SUDFWLFH PDNHV SHUIHFW ³2Q WKH RWKHU KDQG D SRVVLEOH UXSWXUHG DRUWLF DQHXU\VP UHTXLUHV TXLFN WUHDWPHQW 7KHUHIRUH WKH ,QVSHFWRUDWH understands that a strong reduction in centers performing abdominal aorta aneurysm surgeries should not be aspired”.38 This statement refers
to concerns that were raised about the effects of concentration of elective care on acute care.39,40 Not meeting volume thresholds may require a
KRVSLWDOWRVWRSSURYLGLQJFHUWDLQSURFHGXUHVIRUWKHLUSDWLHQWV,QGRLQJVR KRVSLWDOVULVNORVLQJH[SHUWLVHWKDWJRHVEH\RQGWKHORZYROXPHSURFHGXUH especially in the acute care setting.41 )RULQVWDQFHWKHGLVDSSHDUDQFHRI
abdominal aortic procedures in a low-volume center can also lead to loss RI VXUJLFDO VNLOOV LQ DFXWH VLWXDWLRQV $FFRUGLQJ WR WKH ,QVSHFWRUDWH WKLV consequence was thoroughly discussed before the volume standard was published and that the Dutch Surgical Association concluded that the EHQH¿WV RI FRQFHQWUDWLRQ RXWZHLJK WKH ULVN RI WUDQVSRUWDWLRQ39 In their
DQQXDOUHSRUWRQKRVSLWDOLQGLFDWRUVWKH,QVSHFWRUDWHLOOXVWUDWHGWKH dilemma surgeons face in a hospital where abdominal aortic procedures are no longer performed and a patient with a ruptured aneurysm presents itself.42
2YHU WKH \HDUV YROXPH FULWHULD IRU RWKHU VXUJHULHV ZHUH DGGHG WR WKH KRVSLWDO SHUIRUPDQFH LQGLFDWRU VHW SDQFUHDWLF UHVHFWLRQV F\VWHFWRP\ OXQJ UHVHFWLRQ EDULDWULF VXUJHU\ RYDULDQ FDQFHU VXUJHU\ SURVWDWHFWRP\ EUHDVW FDQFHU VXUJHU\ JDVWULF UHVHFWLRQV DQG SDFHPDNHU LPSODQWDWLRQ (2015).
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
RI 'XWFK KRVSLWDOV LQ $OJHPHHQ 'DJEODG D ODUJH 'XWFK QHZVSDSHU DQG (OVHYLHU 0DJD]LQH KDYH EHFRPH D ¿[HG IHDWXUH LQ SXEOLF DFFRXQWDELOLW\ ,QWKLVUHVSHFWPDLQVWUHDPPHGLDKDYHKHOSHGSURYLGHHDVLO\DFFHVVLEOH information on quality of care for the public. Reactions from hospitals whose data are presented publicly vary from defensiveness and dismissive to motivated for quality improvement. The latter refers to the desired “burning platform” effect of publishing performance information.28
Contracts and control (2009-2017)
'HVSLWH LQWHQWLRQV WR UHWUHDW DQG OHW PDUNHW IRUFHV RSHUDWH WKH 'XWFK government intervened because of rising healthcare costs and economic crisis.24 ,Q WKH'XWFK0LQLVWU\RI+HDOWK:HOIDUHDQG6SRUWUHTXHVWHG
FRPSUHKHQVLYH VDIHW\ QRUPV EDVHG RQ KLJKULVN KHDOWK FDUH SURFHVVHV ZKLFKLQFOXGHGPLQLPXPYROXPHVWDQGDUGVIRUKLJKO\FRPSOH[ORZYROXPH procedures.43 The Dutch government negotiated a national agreement
aimed at cost containment with representatives of all stakeholders in specialist care.44$PRQJRWKHUPHDVXUHVKHDOWKLQVXUHUVZHUHHQFRXUDJHG
WR LQFUHDVLQJO\ DSSO\ VHOHFWLYH FRQWUDFWLQJ EDVHG RQ YROXPH SULFH DQG TXDOLW\ 1HYHUWKHOHVV VHYHUDO SROLWLFDO SDUWLHV KDYH UDLVHG FRQFHUQV LQ Dutch Parliament about the autonomous raising of minimum volume standards by health insurers and the resulting confusion among patients and health care providers.45,46 ,QKHDOWKLQVXUHU&=*URXSSXEOLVKHG
a list of Dutch hospitals assigned to categories ranging from “best” to “not eligible for a contract” based on CZ Group’s selection criteria for breast cancer care.47 This new approach was met with mixed reviews. The Minister
RI+HDOWK&DUH:HOIDUHDQG6SRUWWKH,QVSHFWRUDWHDQGSDWLHQWDGYRFDWHV applauded the explicit choice for contracting based on quality. Criticism came from professional organizations and even prompted legal action. 7KHPDLQSRLQWRIFULWLTXHZDVWKHOLPLWHGVFLHQWL¿FVXEVWDQWLDWLRQIRUWKH FULWHULDHVSHFLDOO\DPLQLPXPYROXPHWKUHVKROGRIQHZSDWLHQWVZLWK DEUHDVWFDQFHUGLDJQRVLVDQGRSHUDWLRQVD\HDU,QKHDOWKLQVXUHU CZ Group still maintains the same categories for selective purchasing of breast cancer care and raised the volume thresholds for primary breast cancer operations from 70 to 75.48 Health insurers “raise the bar” in an
effort to distinguish themselves from their competitors.
7KH 'XWFK $VVRFLDWLRQ RI 8URORJ\ LQWURGXFHG WKH ¿UVW PLQLPXP YROXPH VWDQGDUGVIRUF\VWHFWRPLHVLQ,QWKH'XWFK6XUJLFDO$VVRFLDWLRQ IROORZHG ZLWK WKH ¿UVW FRPSUHKHQVLYH QRUP VHW IRU VXUJHU\ LQ JHQHUDO DQGVSHFL¿FVXUJLFDOSURFHGXUHV6LQFHWKHQVL[QHZHGLWLRQVKDYHEHHQ published containing both qualitative and quantitative norms.49-55 Surgical
procedures are divided into four different categories (table 1). The Dutch society for Neurosurgery based their minimum volume standards on the VDPHUDWLRQDOHDOWKRXJKQHXURVXUJHU\LQWKH1HWKHUODQGVKDVEHHQKLJKO\ regulated and centralized in 13 centers.56 In their publication of quality
VWDQGDUGVQHXURVXUJHRQVQRWHWKDWWKHLQWURGXFWLRQRIPLQLPXPYROXPH thresholds could lead to unwarranted overproduction. They emphasize the importance of collaboration and value the qualitative norms higher WKDQWKHLUTXDQWLWDWLYHFRXQWHUSDUWV,QSURIHVVLRQDODVVRFLDWLRQVLQ FDQFHUFDUHSXEOLVKHGWKH¿UVWVHWRIFRPSUHKHQVLYHQRUPVIRUDOOWXPRU W\SHVLQFOXGLQJPLQLPXPYROXPHVWDQGDUGV57 ,QWKH¿IWKHGLWLRQZDV
published.58 The Inspectorate incorporated minimum volume standards
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
No. Categories Surgical procedures
I Surgical procedures for which only quality
standards for the health care institution DUHHVWDEOLVKHG%\H[FHSWLRQDPLQLPXP YROXPHVWDQGDUGRID\HDUFDQEHVHW which should be considered as a stepping stone to a higher category.
VDUFRPDLQÀDPPDWRU\ERZHO GLVHDVHperipheral arterial occlusive disease (PAOD), SHGLDWULFVXUJHU\ procedures)
I/II Combination of no. I and II endocrine surgery
gastric resections
II +LJKO\FRPSOH[ORZYROXPHVXUJLFDO
procedures for which quality standards for WKHKHDOWKFDUHLQVWLWXWLRQDUHHVWDEOLVKHG supplemented by a minimum volume standard of 20 a year.
PHODQRPDSHULWRQHDOFDQFHU HVRSKDJHDOUHVHFWLRQV SDQFUHDWLFUHVHFWLRQVOLYHU UHVHFWLRQVrectal cancer surgery OXQJUHVHFWLRQVDQHXU\VP UHSDLUVFDURWLGVXUJHU\
YHUWHEUDOIUDFWXUHVWUDXPDOHYHO SHGLDWULFVXUJHU\ SURFHGXUHV
III High and low complexity, high volume
surgical procedures for which no evidence of a minimum volume standard that leads to better quality is available. For these procedures, quality standards for the health care institution are established, supplemented by a minimum volume standard of 50 a year.
EUHDVWFDQFHUVXUJHU\colon cancer surgery, endoscopy by surgeons
IV +LJKDQGORZFRPSOH[LW\KLJKYROXPH
surgical procedures for which quality standards for the health care institution DUHHVWDEOLVKHGVXSSOHPHQWHGE\an evidence-based minimum volume standard.
bariatric surgery
Table 1
Return of trust (2017 and beyond)
,QDIWHU\HDUVRILQFOXGLQJYROXPHFULWHULDDVKRVSLWDOSHUIRUPDQFH LQGLFDWRUV WKH ,QVSHFWRUDWH KDV HQGHG WKLV SROLF\ SUDFWLFH $FFRUGLQJ WR WKH ,QVSHFWRUDWH WKH TXDOLW\ LQGLFDWRUV IRU PLQLPXP YROXPH KDYH reached their goals and therefore will no longer be part of the annual hospital performance indicator set.59 Exceptions are made for procedures
LQD¿HOGRIVXUJHU\WKDWKDVQHYHUEHIRUHHVWDEOLVKHGPLQLPXPYROXPH VWDQGDUGV HJQHXURVXUJHU\ DQGRURQVSHFL¿FUHTXHVWE\DSURIHVVLRQDO associations (e.g. pediatric surgery) and/or for high-risk procedures with minimum volume standards that have been established over three years ago and still need enforcing (e.g. gastric resections). Volume thresholds KDYHEHFRPHD¿[HGIHDWXUHLQTXDOLW\VWDQGDUGVGHYHORSHGE\SURIHVVLRQDO DVVRFLDWLRQV)XUWKHUPRUHWKHDWWHQWLRQKDVLQFUHDVLQJO\VKLIWHGWRRWKHU PHDVXUHVIDFLOLWDWHGE\LQLWLDWLYHVVXFKDVWKH'XWFK,QVWLWXWHIRU&OLQLFDO Auditing (DICA).60
$IWHU PRUH WKDQ D GHFDGH KHDOWK LQVXUHUV KDYH QRW EHHQ DEOH WR IXO¿OO the role of prudent buyer of care as envisioned in the reform.27 Their
bargaining position is still relatively weak in an increasingly concentrated hospital market.61 The mobilization of public support against unfavorable
contracting has also been successful over the years. Both providers and consumers have been critical about restrictions to the freedom of choice of provider.62 Health insurers are therefore reluctant to implement selective
contracting in fear of losing enrollees. Trust is an important issue in whether or not enrollees accept health insurers to act as good purchasing agents on their behalf.63 The CEO of health insurer VGZ pointed out: “We
FRQVLGHUHG RXUVHOYHV DV WKH JXDUGLDQV RI TXDOLW\ RI FDUH +RZHYHU ZH have noticed that the outside world does not tolerate this role”.64 Starting
LQ 9*= ZLOO PDLQWDLQ WKH VDPH PLQLPXP YROXPH VWDQGDUGV DV prescribed by professional associations.65 Health insurers are shifting their
focus to facilitating competition on good practices and sensible healthcare in collaboration with medical professionals.27
Implications of minimum volume standards
,QWHUQDWLRQDO¿QGLQJV
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
LQ HDFK KHDOWK FDUH V\VWHP H[DPSOHV RI VLPLODU SROLFLHV DUH IRXQG LQ other European nations.66-73 ,Q WKH 8QLWHG 6WDWHV RI $PHULFD 86$ WKH
Leapfrog Group is the most notable promoter of volume-based quality measures.74,75 Many authors have put the Leapfrog thresholds to the
WHVW ZLWK YDU\LQJ UHVXOWV4,74-80 ,QWHUQDWLRQDO UHVHDUFK VKRZLQJ EHQH¿FLDO
effects of volume on outcomes for patients is abundant.3-22 Perhaps the
PRVWFRPSHOOLQJZD\WRLOOXVWUDWHWKHEHQH¿WVLVFDOFXODWLQJWKHQXPEHURI lives that could be saved when steering patients away from low-volume providers.81-85 +RZHYHU UHGLUHFWLRQ RI SDWLHQWV WR KLJKYROXPH SURYLGHUV
can have unintended consequences for both low- and high-volume IDFLOLWLHV7KHLPSDFWRIORVLQJYROXPHVWUHWFKHVIXUWKHUWKDQWKHVSHFL¿F procedure for which volume standards are enforced. It could negatively LPSDFW D KRVSLWDO¶V RU VXUJHRQ¶V SUR¿FLHQF\ WR PDQDJH DFXWH FDVHV DQG related elective procedures without volume standards.20,40,86 Attracting
RU PDLQWDLQLQJ TXDOL¿HG SURIHVVLRQDOV FDQ DOVR EH PRUH FKDOOHQJLQJ IRU these low-volume centers.20 High-volume centers have to accommodate
PRUHSDWLHQWVZKLFKFRXOGOHDGWRRYHUEXUGHQLQJWKHLUV\VWHPDQGFUHDWH extra waiting times.87,88 Increased travel distances can create barriers to
timely and high-quality care for those without easy access and limited WUDQVSRUWDWLRQ$VDUHVXOWH[LVWLQJGLVSDULWLHVEHWZHHQSDWLHQWVWUHDWHGLQ high- and low-volume hospitals can worsen for patients in rural areas and/ or from a certain socioeconomic status.88-95 ,QDGGLWLRQWRSUDFWLFDOLVVXHV
treatment at a local center keeps patients near their personal support systems and familiar providers for continuity-of-care.96
Implications in Dutch context
The introduction of market incentives introduced new challenges for Dutch KRVSLWDOV 7KHLU ¿QDQFLDO ULVNV DQG SUHVVXUH IURP KHDOWK LQVXUHUV DQG competitors have increased. Mergers are a way to strengthen market or bargaining power. The number of hospitals decreased from 160 in 1985 to 79 in 2016.97,98 The introduction of selective contracting by health insurers
was an important motive for hospital mergers between 2005 and 2012.97
The Netherlands Authority for Consumers and Markets (ACM) assesses collaborations in hospital care services to prevent harm to buyers (patients and insured/insurers).99 8QGHUWKH'XWFK&RPSHWLWLRQ$FWDQ\SRWHQWLDOO\
,Q$&0SURKLELWHGDKRVSLWDOPHUJHUIRUWKH¿UVWWLPH100
Especially smaller hospitals have been forced out of the market in the last decade.101 Minimum volume standards have caused a decrease in the
total number of hospitals performing certain surgeries. The percentage of these remaining hospitals that do not meet volume thresholds has also decreased over the years. Figure 2 displays this trend for surgeries for which volume criteria have been included in the hospital performance LQGLFDWRU VHW IURP WR )RU RHVRSKDJHDO UHVHFWLRQV WKH VKDUS decline since 2007 coincides with the enforcement of the volume threshold E\WKH,QVSHFWRUDWH2YHUDOOFRPSOH[VXUJHULHVDUHLQFUHDVLQJO\SURYLGHG by Dutch hospitals that meet the standards for minimum volume.
Figure 2
Trend of Dutch hospitals not meeting volume thresholds 2004-2015
34,36,38,39,42,95,102-107
Research has shown that Dutch hospitals are easily accessible.108 On
average patients travel 13 minutes and about 75% chooses the closest KRVSLWDOGHSHQGLQJRQWKHFRQGLWLRQDQGWUHDWPHQW+RZHYHUQHDUO\KDOI RI SDWLHQWV DUH SUHSDUHG WR WUDYHO PLQXWHV $ VWXG\ E\ 7DQNH Ikkersheim investigated the trade-off between quality and accessibility for breast cancer care in the Netherlands.109 Based on their quantitative
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
PRGHO EUHDVW FDQFHU WUHDWPHQW IDFLOLWLHV DUH WRR GLVSHUVHG DQG FRXOG EHUHGXFHGWRDVLJQL¿FDQWORZHUQXPEHUJLYHQWKHFRPSDFWVL]HRIWKH Netherlands. Research has also shown that the utilisation of healthcare is HTXLWDEOHZLWKVPDOOGLIIHUHQFHVEHWZHHQVXEJURXSVEDVHGRQHGXFDWLRQ or ethnicity.24
Reference ¿UVW author, year) Study period Surgical procedure N D ata source
Volume and outcome variables
Conclusion +HUPDQV 2016 110 2006- 2012 ra dical cystectom y (RC) Netherlands Cancer R egistry Hospital v o lume R
ates of pelvic lymph node dissection (PLND) Rates of node-positiv
e disease (pN+) After centr alization of FDUH3/1'GXULQJ5& IRUF 7D1RU1[0
urothelial carcinoma has become standard in all types of Dutch hospitals.
(JJLQN 2016 111 2004- 2013 epithelial o varian cancer (EOC) Netherlands Cancer R egistry +RVSLWDOY ROXPHKRVSLWDO
W\SHVXUJLFDORXWFRPH (extent of macroscopic residual tumor after surgery) and o
ver
all
surviv
al
Changes in treatment sequence (primary debulking surgery and adjuv
ant chemother
apy
(PDS+ACT) or neo- adjuv
ant chemother
apy
and interv
al debulking
surgery (NACT+IDS))
Changes in pattern of care for patients with EOC in the Netherlands have
led to impro
vement
in surgical outcome and surviv
al. V an der *HHVW 2016 112 2005- 2013 Pa ncreatoduode-nectom y (PD)
for primary pancreatic or periampullary carcinoma
Netherlands Cancer R egistry KRVSLWDOY ROXPH postoper ativ e mortalit y GD \ R Y H UDOO surviv al (OGHUO\SDWLHQWVEHQH¿ W from centr alization by undergoing PD in KLJK Y ROXPHKRVSLWDOV
both with respect to postoper
ativ
e mortalit
y
and surviv
al.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Reference ¿UVW author, year) Study period Surgical procedure
N
D
ata source
Volume and outcome variables
Conclusion 2QHWH 2015 113 2004- 2009 Pa ncreatoduode-nectom y (PD)
pathology reports in a nation
wide pathology database +RVSLWDOY ROXPHR Y H UDOO UHVHFWLRQU DWHV LPSUR Y HGU DGLFDO 5
quality of pathology reports
Centr
alization of PD w
as
associated with both higher resection r
ates
and more reported R0 resections.
+HQQHPDQ 2014 114 1989- 2009 esophagectom y Netherlands Cancer R egistry KRVSLWDOY ROXPHPRQWK and 2 y ear mortalit y r ates Centr alization of esophagectom y to a minimum of 20 resections/y
ear has been
effectiv
ely introduced
in the Netherlands. Increasing annual hospital v
o
lume w
as
associated with a nonlinear decrease in mortalit
y up to 40-60
HVRSKDJHFWRPLHV\
HDU
after which a plateau w
as reached. *RRLN HU 2014 115 2000- 2009 Pa ncreatic surgery Netherlands Cancer R egistry +RVSLWDOY ROXPHVXUYLY DO after resection Centr alization of
pancreatic cancer surgery led to increased resection rates.
Reference ¿UVW author, year) Study period Surgical procedure N D ata source
Volume and outcome variables
Conclusion -DQVVHQV 2012 116 1996- 1998 2001- 2006. Pe diatric tr auma care surv
eillance-based before- after study in-hospital mortality rate before and after regionalization of tr
auma
care in the Netherlands
R
egionalization of tr
auma
care in the Netherlands reduced the in-hospital mortalit
y r
ates for
adolescents in the last GHFDGH+RZHY
HU WKLV reduction w as not caused by a change in referr al beha viour . V an den (LQGHQ 2012 117 1989- 1999 2000- 2008 vulv ar carcinoma 382
cancer registry Comprehensiv
e Cancer Centre R elativ e surviv al r ates C entr alisation of care for vulv ar SCC patients
has been well adopted in the Eastern part of the Netherlands. Being treated in a specialised oncology centre w
as
associated with a better surviv
al after adjustment
for age and stage.
'H:LOGH 2012 118 2004- 2009 Pa ncreatico-duodenectom y (PD) .LZ D3ULVPDQW registry +RVSLWDOY ROXPHLQ hospital mortalit y r ate With nation wide FHQWU DOL]DWLRQRI3' WKH
in-hospital mortality rate after this procedure decreased.
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Reference ¿UVW author, year) Study period Surgical procedure
N
D
ata source
Volume and outcome variables
Conclusion
/HPPHQV 2011
119
1995- 2000 2005- 2008
primary cancer of the SDQFUHDWLFKHDG extr
ahepatic bile GXFWVDPSXOOD of V ater or duodenum Netherlands Cancer R egistry +RVSLWDOY ROXPH UHVHFWLRQU DWHVLQ KRVSLWDOPRUWDOLW \ \ HDU surviv al and changes in treatment patterns
High-quality care can be achiev
ed in
regional hospitals through collabor
ation.
Centr
alization should
no longer be regarded as a threat b
y gener
al
hospitals but as a chance to impro
ve outcomes in pancreatic cancer . *RRLN HU 2011 120 1996- 2000 2001- 2005 2006- 2008
resection for suspected pancreatic cancer
249
Comprehensiv
e
Cancer Centre West (CCCW)
+RVSLWDOY ROXPHVXUYLY DO Centr alization of pancreatic surgery w as
successful and has resulted in impro
ved
clinical outcomes in the western part RIWKH1HWKHUODQGV demonstr
Reference ¿UVW author, year) Study period Surgical procedure N D ata source
Volume and outcome variables
Conclusion V an de 3 ROO)U DQVH 2011 121 1995- 1998 1999- 2006
oesophageal and gastric cardia cancer
Eindho ve n Cancer R egistry long-term surviv al C oncentr ation of
oesophageal and gastric cardia cancer surgery was associated with impro
vements in
long-WHUPSRSXODWLRQEDVHG ov
er
all surviv
al for
surgically as well as non-surgically treated SDWLHQWVDSSDUHQWO\ mediated by an increase in v
o
lume.
1LHQKXLMV 2010
122
1995- 2000 2005- 2009
resection of a pancreatic tumour
76
Prospectiv
e data
+RVSLWDOY
ROXPHVXUJLFDO
morbidity and in-hospital mortality
These data deriv
ed from daily pr actice in a collabor ativ e surgical
region in The Netherlands (CCCS) support the need for centr
alisation
of pancreatic surgery in order to impro
ve
standard of care in pancreatic surgery
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
Reference ¿UVW author, year) Study period Surgical procedure
N
D
ata source
Volume and outcome variables
Conclusion : RXWHUV 2009 123 1990- 2004 esophagectomies for cancer
555 clinical data +RVSLWDOY ROXPH SRVWRSHU DWLY HPRUELGLW \ OHQJWKRIVWD \PRUWDOLW \ surviv al V o lume is an important determinant of qualit y of
care in esophageal cancer surgery
. R
eferr
al of
patients with esophageal cancer to surgical units with adequate experience and superior outcomes (outcome-based referr
al)
impro
ves qualit
y of care.
Discussion
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6
patients and health insurers.60 Another promising effort comes from the
International Consortium for Health Outcomes Measurement (ICHOM). ,QWHUQDWLRQDO PXOWLGLVFLSOLQDU\ ZRUNLQJ JURXSV GHYHORS VWDQGDUG VHWV RI SDWLHQWFHQWHUHG RXWFRPHV IRU OXQJ FDQFHU FRURQDU\ DUWHU\ GLVHDVH breast cancer and colorectal cancer.124-127
7KLUG DQG ¿QDOO\ YROXPH UHPDLQV D FRQWURYHUVLDO TXDOLW\ PHDVXUH DQG therefore is not conducive for continuous quality improvement. Minimum volume standards imply that a cut-off point can be used to discriminate between high and low quality. Reviews have shown that determining numerical thresholds based on volume-outcome research is often impossible.19,128-133 7KHGH¿QLWLRQRIKLJKDQGORZYROXPHKRVSLWDOVYDULHV
IRUGLIIHUHQWSURFHGXUHVDQGLQVRPHLQVWDQFHVEHWZHHQVWXGLHVDQDO\]LQJ the same procedure. Applying volume standards can unfairly bypass high-quality low-volume providers and overestimate the performance of low-quality high-volume providers. Besides limitations in determining PHDQLQJIXO WKUHVKROGV WKHUH LV ZLGH FRQVHQVXV WKDW YROXPH DV VXFK LV an imperfect correlate of quality.16,22,86,134 Volume alone does not lead to
EHWWHUTXDOLW\EXWDFWVDVDSUR[\IRURWKHUIDFWRUVWKDWGLUHFWO\LQÀXHQFH outcomes.Quality improvement requires an understanding of the working mechanism and of what volume represents. After decades of research only a limited amount of studies focus on the circumstances under which volume and outcome show a positive association.135 ,Q DGGLWLRQ WKH
methodological rigor of volume-outcome studies is modest. The likelihood that steering on volume alone will produce consistent and continuous LPSURYHPHQWVLQTXDOLW\RIFDUHLVVPDOO2JEXXUJHVFDXWLRQDQGÀH[LELOLW\ as approaches may vary for each condition.136 Empirical evidence for an
inverse relationship between hospital volume and mortality does not necessarily have policy relevance. A restriction in hospitals that carry out abdominal aortic aneurysm repairs is likely to improve outcomes. :KHUHDVVXFKUHVWULFWLRQVEDVHGRQVLPLODUHYLGHQFHIRULVFKHPLFVWURNH would be harmful for patients.137,138 3ROLF\PDNHUVKHDOWKFDUHSURYLGHUV
and researchers should remain focused on exploring measures that are truly targeted at causal factors. The Inspectorate has already announced the end of volume criteria in the Hospital performance indicator set and more focus on indicators relating to coordination and collaboration in complex care.
VWDQGDUGV )XUWKHUPRUH PRUH UHVHDUFK LV QHHGHG RQ WKH LPSOLFDWLRQV of minimum volume standards. While implementing minimum volume VWDQGDUGVFDQLPSURYHTXDOLW\RIFDUHWKHRYHUDOOHIIHFWRQSDWLHQWZHOIDUH and quality of the health care system as a whole remains unclear.
Conclusion
This current evaluation of minimum volume standards in the Netherlands KDV VKRZQ WKDW VWDNHKROGHUV DOWHUQDWHG LQ WDNLQJ WKH OHDG LQ NHHSLQJ with their changing roles in Dutch health care. The policy has effectively decreased the number of low-volume hospitals performing complex surgeries in the Netherlands and research has shown improved outcomes DVDUHVXOW%DVHGRQWKH'XWFKH[SHULHQFHWKHIROORZLQJOHVVRQVFDQEH useful for other health care systems: 1. professionals should be in the lead in the development of national quality standards such as minimum volume thresholds. 2. external pressure can be helpful for professionals to take the initiative and 3. volume remains a controversial quality measure and therefore not conducive for continuous quality improvement. Future research and policies should focus on the underlying mechanism of volume-outcome relationships and overall effects of volume-based policies.
References
1. World health organisation. WHO Guidelines for Safe Surgery 2009. Safe Surgery Saves Lives. Geneva. 2009. Available at: http://www.who. int/patientsafety/safesurgery/tools_resources/9789241598552/en/ [accessed 02.03.17]. 3HDUVH500RUHQR53%DXHU33HORVL30HWQLW]36SLHV&HWDO0RUWDOLW\ DIWHUVXUJHU\LQ(XURSH $GD\FRKRUWVWXG\/DQFHW ± 65. 6FKUDJ'&UDPHU/'%DFK3%&RKHQ$0:DUUHQ-/%HJJ&%,QÀXHQFH of hospital procedure volume on outcomes following surgery for colon cancer. JAMA 2000;284:3028-35.
%LUNPH\HU-'6WXNHO7$6LHZHUV$(*RRGQH\33:HQQEHUJ'(/XFDV FL. Surgeon volume and operative mortality in the United States. N Engl J Med 2003;349:2117-27.
'LPLFN -% 8SFKXUFK *5 -U (QGRYDVFXODU WHFKQRORJ\ KRVSLWDO YROXPH and mortality with abdominal aortic aneurysm surgery. J Vasc Surg 2008;47:1150-4.
