Tilburg University
The choice determines the success
de Vries, J.; den Oudsten, B.L.
Published in:
Nederlands Tijdschrift voor Orthopaedie
Publication date: 2014
Document Version
Publisher's PDF, also known as Version of record Link to publication in Tilburg University Research Portal
Citation for published version (APA):
de Vries, J., & den Oudsten, B. L. (2014). The choice determines the success: PROMS. Nederlands Tijdschrift voor Orthopaedie, 21(2), 39-42.
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Introduction
Patient-reported outcomes (PROs) have gained im-portance in clinical practice and medical research. This growing interest is related to the shift in at-tention from doctor-oriented to patient-oriented medicine. Moreover, in recent years, the audience with an interest in PROs has broadened. Not only patients and clinicians are interested in PROs, but also regulators, policy makers and health technol-ogy assessment authorities. The goal is to ensure the best outcome for patients after treatment or for making decisions about product approval. PROs are assessed with patient-reported outcome measures (PROMs). There is a plethora of question-naires, which can be used as PROMs. It can be quite difficult to choose questionnaires, because there are several aspects that should be taken into ac-count. Although PROMs are often selected because they are commonly used or are available in a wide range of languages, such factors are not the only factors to consider and may even be minimal com-pared to other factors. For instance, the most es-sential questions to be answered are ‘what do we intend to measure?’, ‘in which target population?’, and ‘for which purpose?’. Moreover, another impor-tant aspect is ‘how good are the psychometric prop-erties of PROMs?’. It is important to answer these questions adequately, since choosing the ‘wrong’ PROM may lead to disappointment and wrong use of interpretation of data. The Dutch Orthopedic Association (Nederlandse Orthopaedische Verenig-ing; NOV) has formulated and chosen criteria for suitable PROMs.1 A step that precedes this is the
question of what each PROM exactly measures and
more importantly, what you want to know, before even choosing a measure. In this overview, we will discuss the concepts PRO and PROMS and discuss how to choose the ‘right’ PROMS.
The concept PRO
PROs can be measured directly from patients about how they function or feel in relation to a health condition and/or its treatment without interpreta-tion from another person.2 Patients’ evaluations
can be obtained through interviews, self-report questionnaires, and diaries. As such, proxy reports from caregivers or clinicians cannot be considered PROs. PROs should not be confused with patient-based outcomes. The latter implies that the issues covered are specific concerns of patients. This is not a prerequisite of PROs.2 PROs is an umbrella
term that covers a wide range of concepts. The common denominator is that PRO data refers to pa-tients’ self-reports.
Examples of PROs are functional status (FS), health status (HS), and (health-related) quality of life ((HR)QOL). Functional status refers to patients’ general physical functioning.3
Although the nomenclature of HS and (HR)QOL is distinct (Figure 1), in practice these con-cepts are used interchangeably.3 The lack of clarity may be
due to the fact that these concepts share several common grounds, while concerning content these concepts are not equivalent. HS, HRQOL and QOL are all self-reported (i.e. subjective) and multidi-mensional assessing at least three domains: physi-cal, psychologiphysi-cal, and social. Both HS and HRQOL are bound to health, while QOL is broader than health. QOL encompasses the patient’s subjective evalua-tions of their own well-being.3 It can be
as-sessed with questions like: ‘How satisfied are you with your ability to perform your daily living activi-ties?’. This reflects an evaluation of per-formance. Moreover, QOL also captures positive aspects ex-perienced by patients in life, such as positive feel-ings. HRQOL is more narrowly defined and the focus is on those QOL com-ponents that are impacted by a disease or condition, for instance ‘How much are
Prof. dr. J. De Vries1,2 and Dr. B.L. den Oudsten1,3
1 CoRPS - Center of Research on Psychology in Somatic Diseases, Department of Medical and Clinical Psychology, Tilburg University, Tilburg, The Netherlands
2 Department of Medical Psychology, Tilburg, The Netherlands
3 Department of Education and Research, St. Elisabeth Hospital, Tilburg, The Netherlands Corresponding author: Prof. dr. J. De Vries Email: j.devries@tilburguniversity.edu
The choice determines the success: PROMs
Jolanda de Vries and Brenda den Oudsten
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you troubled by problems with stiffness and pain?’. For instance, QOL and HRQOL are also ‘subjective’ in the sense that patients indicate how they feel about and experience their ability to function. HS assesses physical possibilities, state of mind and social activities without an evaluation or feelings about functioning.3 An example question is: ‘Are
you able to climb the stairs?’. Thus, HS indicates whether the patient experiences any limitations. Although the patient reports his/her own limita-tions, it still is an objective measure of functioning. As a result, two persons may have the same score on a HS instrument, but can have different scores on a (HR)QOL questionnaire.3 For example, an
old-er patient who is still physically active will have a lower QOL, when she has a tendon injury, than an older patient who likes to read. Figure 1 shows the relationship between QOL and related concepts.
PROMs
Besides FS, HS, and (HR)QOL, PROMs can also as-sess symptoms, general health percep-tions, or satisfaction with treatment.3,4 For example, the
term PROMs covers a wide range of potential types of measurements. Assessing PROs with PROMs have a number of potential benefits.5 They may
facili-tate the detection of issues that might otherwise be overlooked5, for instance, depressive symptoms
which are related to lower adherence of the treat-ment.6 PROMs can also be used to monitor the
ef-fects of disease progression and to provide infor-mation about the (potential) impact of prescribed
treatment.5 PROMs used in routine clinical care may
facilitate patient-clinician communication about expectations regarding the outcomes of illness and/ or treatment and promote shared decision making when the professional gives patients feedback on their scores on the completed PROM(s).5 In this
way, patients feel taken seriously and will probably experience the consultation as more valuable. As such, the as-sessment of PROs may improve patient satisfaction apart from the fact that paying atten-tion to the patient just by letting him/her complete a PROM also increases patient satisfaction.7 PROMs
may also be used to monitor outcomes as a strategy for quality improvement or even predict the out-comes of care.4,6 Critical notes can also be found
in the literature.8 PROMs were originally developed
for use in research and subsequently adopted to support clinical management.9 However, in order
to safely use the data it is necessary to have suffi-cient knowledge about how to interpret and report the data, to know how these data can be used in clinical practice, and when not to use PROMs.10
PROMs can be divided into generic, disease-specif-ic, or condition-specific measures.3 Generic
meas-ures can be used to assess outcomes in healthy persons as well as patients with any disease or con-dition, while disease-specific measures describe the severity, symptoms, or functional limitations related to a specific disease. Examples of generic measures are the Eu-roQOL- 5 dimensions (EQ-5-D)11 and the Short Form Health Survey (SF-36)12.
Examples of disease-specific measures are the Eu-ropean Organization on Research and Treatment of Can-cer-Quality of Life Questionnaire-Core30 (EORTC-QLQ-C30)13 and the Sarcoidosis Health
Questionnaire (SHQ).14 Condition-specific
meas-ures describe symptoms or experiences relat-ed to a specific condition or problem (e.g., low back pain), or are related to particular treat-ments, such as hip replacement. An example of a condi-tion-specific measure is the Knee Nu-meric-Entity Evaluation Score (Knees-ACL), which assesses im-pairment, functional limita-tions, and psychosocial consequences of persons who have undergone an anterior cruciate ligament reconstruction.14 Other
condition-specific measures are the Hip disability and Osteo-arthritis Outcome Score Physical Func-tion (HOOS hip outcome)16 and the HOOS-PS which
is the short version of the HOOS and the Knee dis-ability and Osteoarthritis Outcome Score.17
A PROM that measures a single construction is uni-dimensional. Items in a uni-dimensional question-naire can be added to provide a single scale score. A multi-dimensional PROM is used to provide a pro-file of scores, in which each subscale is scored and reported separately. It is sometimes possible to cre-Figure 1. Conceptualisation of functional status (FS),
health status (HS), health-related quality of life (HRQOL), and quality of life (QOL).
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ate a total score from a multidimensional measure. However, this will result in loss of information and can no longer be considered multi-dimensional be-cause it cannot be ascertained in which domain the patient has (a) problem(s) or is troubled or satisfied.
PROMS within the field of orthopedics
A commonly used generic instrument is the SF-36. However, although many researchers claim that they have assessed (HS)QOL, this instrument is as-sessing HS.3,18
The EQ-5D and the HOOS have been chosen as standard PROM by the Dutch Orthopedic Society.1
Since pain reduction was also considered to be an important outcome, visual analogue scales have been added. It is a 0 to 10(0) scale for recording an individual’s rating of their pain (or health state) and is often similar to a thermometer.1 It should be
noted that the EQ-5D and the HOOS hip outcome are not QOL measures, but a HS and a FS meas-ure according to the abovementioned definitions. When interested in QOL another measure should be chosen. Besides HS, the EQ-5D can be used to measure health utilities (also health state) and are used to calculate quality-adjusted life years (QALY). A QALY served as a composite indicator al-lows quality and quantity of life to be combined in a single index. Utilities are generally expressed on a numerical scale ranging from ‘0’ (death) to ‘1’ (perfect health). It assumes that a year of life lived in perfect health is worth 1 QALY and that a life lived in a state of less than perfect health is worth less than 1.19 This type of assessment can be used
to determine the cost-effectiveness of interven-tions. If one is interested to assess (HR)QOL, only generic instruments are currently available. That is, the Short Musculoskeletal Function Assessment (SMFA)20 which assesses HRQOL or the World Health
Organization Quality of Life instrument (WHOQOL-100)21 which assesses QOL. The WHOQOL-100
contains 100 items which hampers its practicality in clinical practice, however a short-form is also available (i.e., WHOQOL-BREF).22 Recently, two
systematic reviews provided an overview about the concepts of HS, HRQOL, and QOL and the instru-ments used within the field of distal radius and an-kle fracture.23,24
Selection of PROs and PROMs
The type of PROM should closely correspond to the PRO to be measured. In other words, the research aim will be answered adequately when a suitable PROM is chosen. Suppose we aim to assess QOL, many PROMs will be available. We have already
shown that authors use concepts interchangeably and that PROMs are supposed to measure QOL, but will not assess it per se. It is important to inspect the items of an instrument, since a QOL instrument may assess what patients can actually perform (FS or HS) or may assess to what extent a patient is sat-isfied or troubled by its physical performance ((HR) QOL). When a research aim is adapted, the PROM will probably also change.
Another aspect to evaluate a PROM is the way it is developed. For instance, were items derived from the appropriate source/population? Clinical input is required for the assessment of symptoms and functioning, however, when assessing QOL it is important that during the development, patients are involved in the determination of the content of the questionnaire. In addition, the questionnaire content should be clear and unambiguous and writ-ten in a reading age that most persons will be able to understand. Questionnaires containing double-barreled items damage item clarity and should be avoided. Moreover, questionnaires should be prac-tical in (clinical) practice. For instance, the length of the measures in terms of number of the items is often considered an important selection criterion for a PROM. However, it is usually the profession-als who think that patients are only prepared to answer a few questions, whereas patients feel that the clinician is really interested in him/her, espe-cially when the score of a patient is brought up in the consultation.
It is essential that a PROM meets certain criteria concerning development, as well as psychometric and scaling standards, in order to be able to pro-vide useful information. PROMs should have a sound theoretical basis and should be relevant to the tar-get population. Moreover, PROMs should also be re-liable, valid, and responsive to change. If a PROM is not psychometrically sound, its scores will not be in-terpretable, since these scores are meaningless. Re-liability is defined as the degree to which scores for patients who have not changed, are the same for re-peated measurement under several conditions, that is using different sets of items from the same multi-item PROMs (internal consistency); over time (test-retest reliability), and on different occasions (intra-rater).25-27 Other frequently used terminology for
reliability are: reproducibility, stability, and agree-ment. Validity is defined as ‘the degree to which an instrument truly measures the construction(s) it purports to measure’.25-27 To evaluate the effects
of treatment or other longitudinal changes in, for example QOL, we need PROMs that are sensitive to change. When minimal important change (MID) is applied to PROMs it refers to the smallest score change which patients perceive as important.25
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Another aspect is whether the results should be compared with a norm population or another pa-tient group.25-27 This will determine whether a
generic, disease-specific, or condition specific in-strument should be chosen. The presence of ref-erence population(s) for PROMS will facilitate the interpretation of patients’ scores. An instrument assessing QOL developed in one country is not nec-essarily an adequate measure in an other. This may be due to translation differences or differences in cultural issues. For instance, during the develop-ment of the WHOQOL-100 in the 1990s , traffic safety was an important aspect of QOL according to the Israeli, however in another countries this issue was not relevant. Another aspect in which cultures differed was whether a sexual problem belonged to the physical health domain or should be seen as an aspect of social relationships. Thus, the per-ception of QOL and the way persons deal and ex-press health problems differs between cultures. As a consequence, if the transposition of a measure of its original cultural context is done by simple trans-lation it is unlikely that it will be a good measure, because of language and cultural differences.25,26 Conclusion
PROMs should assess the PRO one intends to meas-ure, be well-developed, culturally adapted if nec-essary, be practical in use, and have good psycho-metric qualities, i.e. be reliable, valid, responsive to change, and the minimal important difference should be known. The EQ-5D, the HOOS and a VAS pain score have been chosen as standard PROMs by the Dutch Orthopedic Society. However, these PROMs cannot be used to assess (HR)QOL. When interested in (HR)QOL another measure should be chosen. Currently, only generic instruments are cur-rently available in the field of orthopedics. The SMFA can be used to assess HRQOL, while the WHOQOL-BREF or WHOQOL-100 can be used to assess QOL.
Abstract
Patient Reported Outcome Measures (PROMs) re-fer to a variety of measures that are used to assess patient-reported outcomes (PROs). PROMs are often selected because they are com-monly used or are available in a wide range of languages. Although important, such factors are not the only factors to consider. PROMs should assess the PRO one intends to measure, such as health status, health-related quality of life (HRQOL) or quality of life (QOL), it should be well-developed, and have good psycho-metric qualities, i.e. be reliable, valid, responsive to change, and the minimal important difference
should be known. In addition, one should ex-amine the practicality of the measure and/or cross cul-tural validity. The EuroQOL- 5 dimen-sions (EQ-5D), the Hip disability and Osteoarthritis Outcome Score Physical Function (HOOS) and a visual analogue scale (VAS) pain score have been chosen as standard PROMs by the Dutch Orthopedic Society. However, it should be noted that these PROMs cannot be used to assess (HR)QOL. When interested in (HR)QOL an-other measure should be chosen. However, within the field of orthopedics only generic instruments are currently available. The Short Musculoskeletal Func-tion Assessment (SMFA) can be used to assess HRQOL or the World Health Organization Quality of Life instrument-100 items (WHOQOL-100) and its short version (WHOQOL-BREF) can be used to assess QOL.
References
1. Nederlandse Orthopaedische Vereniging (NOV). Patient reported outcomes, 2012.
2. Patrick D, Guyatt GH, Acquadro C. Chapter 17: Patient-reported outcomes. In: Hig-gins JPT, Green S (editors), Cochrane Handbook for Systematic Reviews of Interven-tions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Avail-able from www.cochrane-handbook.org.
3. De Vries, J., Quality of life assessment, in Assessment in behavorial medicine, A.J.J.M. Vingerhoets, Editor 2001, Brunner-Routledge: Hove. p. 353-370.
4. Rothman ML, Beltran P, Cappelleri JC, Lipscomb J, Teschendorf B, Mayo/FDA Pa-tient-reported Oucomes Consensus Meeting Group. Patient-reported outcomes: con-ceptual issues. Value Health. 2007; 10: S66-75. 5. Valderas JM, Kotzeva A, Espallargues M, Guyatt G,
Ferrans CE, Halyard MY, Revic-ki DA, Symonds T, Parada A, Alonso J. The impact of measuring patient-reported outcomes in clinical practice: a systematic review of the literature. Qual Life Res. 2008; 17: 179-93.
6. Sundbom LT, Bingefors K. The influence of symptoms of anxiety and depression on medication nonadherence and its causes: a population based survery of prescrip-tion drug users in Sweden. Patient Prefer Adherence 2013; 19:805-11.
7. Chen J, Ou L, Hollis SJ. A systematic review of the impact of routine collection of patient reported outcome measures on patients, providers and health organisation in an oncologic setting. BMC Health Serv Res 2013, 11; 13: 211.
8. Wolpert M. Do patient reported outcome measures do more harm than good? BMJ. 2013; 346: f2669.
9. Black N. Patient reported outcome measures could help transform healthcare. BMJ 2013; 346: 167.
10. Glasziou P, Irwig L, Aronson JK. Evidence-based medical monitoring: from principles to practice. Blackwell, 2008 11. EuroQol - a new facility for the measurement of health-related quality of life. The Eu-roQol Group. Health Policy 1990; 16: 199-208.
12. Ware Jr JE, Sherbourne CD. The MOS 36-item short form
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health survy (SF-36). I. Conceptual framework and item selection. Med Care 1992; 30: 473-83.
13. Aaronson NK, Ahmedzai S, Bergman B, et al. The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst 1993; 85: 365–376.
14. Cox CE, Donohue JF, Brown CD, Kataria YP, Judson MA. The Sarcoidosis Health Questionnaire: a new measure of health-related quality of life. Am J Respir Crit Care Med. 2003, 168: 323-9.
15. Comins J, Krogsgaard M, Brodersen J. Development of the knee numeric-entity evaluation score (KNEES-ACL): a condition specific questionnaire. Scand J Med Sci Sports 2013; 23: 293-301.
16. de Groot IB, Reijman M, Terwee CB, Bierma-Zeinstra SM, Favejee M, Roos EM, Verhaar JA. Validation of the Dutch version of the Hip disability and Osteoarthritis Outcome Score. Osteoarthr Cartil. 2007; 15: 104-109.
17. Roos EM, Lohmander LS. Knee injury and Osteoarthritis Outcome Score (KOOS): from joint injury to osteoarthri-tis. Health Qual Life Outcomes 2003; 1:64.
18. Hamming JP, De Vries J. Measuring quality of life. Br J Surg 2007; 94:923-924.
19. Prieto L, Sacristán JA. Problems and solutions in calcu-lating quality-adjusted life years (QALYs). Health Qual Life Outcomes. 2003; 19: 1-80.
20. Swiontkowski MF, Engelberg R, Martin, DP., Agel, J. Short musculoskeletal function assessment
question-naire: validity, reliability, and responsiveness. J Bone Joint Surg Am 1999; 81: 1245-1260.
21. WHOQOL Group. Development of the WHOQOL: rationale and current status. Int J Ment Health 1994: 23: 24-56. 22. WHOQOL Group. Development of the World Health
Organization WHOQOL-BREF quality of life assessment. Psychol Med 1998; 28: 551-558.
23. Van Son MA, De Vries J, Roukema JA, Den Oudsten BL. Health status and (health-related quality of life during the recovery of distal radius fractures: a systematic review. Qual Life Res 2013 Mar 22.
24. Van Son MA, De Vries J, Roukema JA, Den Oudsten BL. Health status, health-related quality of life, and quality of life following ankle fractures: a systematic review. Injury. Int. J. Care Injured 2013; 44: 1391-1402. 25. Mokkink LB, Terwee CB, Patrick DL, et al. The COSMIN
study reached international consensus on taxonomy, terminology, and definitions of measurement properties for health-related patient-reported outcomes: results of the COSMIN-study. J Clin Epi-demiol 2010; 63: 737-45. 26. Mokkink LB, Terwee CB, Patrick DL, et al. The COSMIN
checklist for assessing the methodological quality of studies on measurement properties of health status meas-urement instruments: an international Delphi study. Qual Life Res 2010; 19: 539-549.
27. Terwee CB, Bot DM, de Boer MR, van der Windt DAWM, Knol DL, Dekker J, Bouter, LM, de Vet HCW. Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol 2007; 60: 34-42.
