University of Groningen Geriatric syndromes; prevalence, associated factors and outcomes Rausch, Christian

Geriatric syndromes; prevalence, associated factors and outcomes

Rausch, Christian

DOI:

10.33612/diss.145064339

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Publication date: 2020

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Rausch, C. (2020). Geriatric syndromes; prevalence, associated factors and outcomes. University of Groningen. https://doi.org/10.33612/diss.145064339

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General discussion

The overall aim of this thesis is to advance knowledge on how geriatric syndromes influence older people’s health status by elucidating their associations with sociodemographic attributes, health behaviors, and health status as well as their effects on severe health outcomes, namely hospitalization and mortality.

This final chapter presents a general discussion divided into two parts: a discussion of the main findings reported in the thesis along with conceptual and methodological considerations and implications for research, policy, and practice.

Main findings

Part I: Geriatric syndromes, prevalence, and associated factors Research questions 1a and 1b examined in chapter 2

1a. What is the prevalence of geriatric syndromes among older community-dwellers?

1b. Are measures of social position associated with geriatric syndromes among older community-dwellers?

Among older community-dwellers in Sweden, around 70.0% reported at least one geriatric syndrome. Measures of lower social position, notably country of origin outside of the Nordic countries, education levels, rented accommodation, and financial stress were associated with the presence of geriatric syndromes. Financial stress and living in rented accommodation (as opposed to self-owned accommodation) were found to be most strongly associated with the presence of geriatric syndromes among older community-dwellers.

Research question 2 examined in chapter 3

2a. Is there a trend of geriatric syndrome prevalence among older community-dwellers?

2b. Which factors are associated with prevalence trends of geriatric syndromes?

The prevalence of geriatric syndromes stayed at a high-stable level from 2006 to 2014 among older community-dwellers in Sweden. Insomnia or sleep problems were identified as the most common geriatric syndrome among individuals aged 65 years and older in Sweden. Between 2006 and 2014, the prevalence of insomnia increased from 38% to close to 46%. Depressive symptoms or depressive disorders were the least common geriatric syndrome with a prevalence ranging between 1.8% and 2.1% between 2006 and 2014. During the same period, the prevalence of insomnia/sleeping problems as well as falls increased (from 38.0% to 45.8% and from 10.8% to 14.7%, respectively). Conversely, the prevalence of hearing and vision impairments as well as functional impairments declined (from 23.1% to 17.6%, 4.9% to 3.5%, and 23.3% to 19.9%, respectively). During this period, the burden of geriatric syndromes increased for older people born outside of the Nordic countries (from 73.0% to 83.0%).

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Aging / underlying dysfunctions

Geriatric syndromes Incontinence Vision and hearing_impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy

Socio-demographic attributes

Social position

Fig. 1. Geriatric syndromes, prevalence, and socio-demographic attributes Fig, 1. Geriatric syndromes, prevalence, and sociodemographic attributes

Research question 3 examined in chapter 4

3. Are geriatric syndromes associated with particular trajectories of physical activity among older community-dwellers?

Over a five-year period, four distinct trajectories of physical activity were identified among older people: high-stable, moderate-decreasing, increasing, and low-stable physical activity. Older people who engaged in low-low-stable physical activity reported the presence of geriatric syndromes more often than those engaged in other physical activity trajectories. The presence of two or more geriatric syndromes at baseline (a prevalence of 21.8%) was associated with trajectories of decreasing or low physical activity over time. This association remained significant after adjusting for sociodemographic attributes, health-related factors, and health behaviors.

Research question 4 examined in chapter 5

4. Are geriatric syndromes associated with incident chronic health conditions?

Older community-dwelling people who reported at least one geriatric syndrome at baseline were at increased risk of developing chronic health conditions over a 43-month period (HR: 1.35, 95% CI: 1.21–1.51). This association remained significant after adjusting for social factors, socioeconomic factors, health status, and health behaviors (HR: 1.27, 95% CI: 1.12–1.43). Older community-dwelling people with geriatric syndromes at baseline showed an increased risk of developing a specific chronic health condition, namely a cardiovascular condition (HR: 1.42, 95% CI: 1.13–1.79) or diabetes (HR: 1.53, 95% CI: 1.11–2.11) during the follow-up period. They had no increased risk of developing cancer, pulmonary diseases (asthma, COPD, chronic bronchitis, and emphysema), or neurological/ neurodegenerative conditions (Parkinson’s disease and dementia).

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Health status Health behaviors

Physical activity

Chronic health conditions Aging /

underlying dysfunctions Geriatric syndromes Incontinence Vision and hearing

impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy

Fig. 2. Geriatric syndromes, physical activity and chronic health conditions Fig. 2. Geriatric syndromes, physical activity, and chronic health conditions

Part II: Falls, polypharmacy and the risks of hospitalization and mortality Research question 5 examined in chapter 6

5. Taking inappropriate drug use among older individuals into consideration, are increasing numbers of prescribed medications associated with hospitalization and mortality due to adverse drug events by unintentional poisoning?

A higher number of different medications (two or more) was associated with a higher risk of hospitalization and mortality due to unintentional poisoning. This association remained valid for three or more medications when inappropriate drug use was excluded (adjusted odds ratios, OR excl. inappropriate drug use, IDU 1.5, 95% CI: 1.2–2.0). The risk for hospitalization and mortality due to unintentional poisoning increased with an increasing number of medications dispensed in a dose-response manner. This association was also apparent among older people aged 50+ years and remained tenable after adjusting for sociodemographic factors and comorbidity levels.

Research question 6 examined in chapter 7

6. Taking existing clinical conditions among older individuals into consideration, are injurious falls associated with subsequent hospitalization and mortality due to a adverse drug events by unintentional poisoning?

Older people who experienced injurious falls were at increased risk for subsequent hospitalization and mortality attributed to adverse drug event unintentional poisoning than those who did not experience injurious falls. The risk of hospitalization or mortality tripled within six months following an injurious fall, with the highest risk occurring within three weeks after an injurious fall (adjusted OR: 8.86; 95% CI: 5.76–13.6). These associations did not evidence any significant changes after adjusting for sociodemographic factors, civil status, and comorbidity levels (adjusted OR: 7.69; 95% CI: 4.87 – 12.1). Older people who experienced unintentional poisoning events after injurious falls tended to have a higher comorbidity level and to receive more opioids and analgesics after their falls.

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impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy

Fig. 3. Geriatric syndromes and hospitalization and mortality due to unintentional poisoning

Discussion of the main fi ndings

Part I:

Geriatric syndromes, their prevalence, and associated factors among older community-dwellers in Sweden and the Netherlands

Chapters 2 and 3:

The prevalence of geriatric syndromes and social position among older community-dwellers in Sweden

Chapter 4:

Geriatric syndromes and trajectories of physical activity in older community-dwellers in the Netherlands

Chapter 5:

Geriatric syndromes and subsequent chronic health conditions among older community-dwellers in the Netherlands

Health outcomes

Health status Health behaviors

Physical activity

Chronic health conditions Aging /

underlying dysfunctions

Mortality Hospitalization

Geriatric syndromes

Incontinence Vision and hearing_impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy II II Socio-demographic attributes Social position I I I Part II:

Polypharmacy, falls, and the risk of hospitalization and mortality

Chapter 6:

Polypharmacy, hospitalization, and mortality due to unintentional poisoning

Chapter 7:

Injurious falls, hospitalization, and mortality due to unintentional poisoning

Fig. 3. Thesis components and the geriatric syndrome concept Fig. 4. Geriatric syndromes, scheme of this PhD

Part I: Geriatric syndromes, prevalence, and associated factors Geriatric syndromes, prevalence, and social position

Th e results of this study indicate stable prevalence of geriatric syndromes over time with diff erences in the prevalence of specifi c geriatric syndromes at the population level. Meinow et al., who studied the prevalence of complex health issues among older Swedes since 1996, reported stable prevalence of these health issues starting from 2002 [1]. Our results covering the years 2006 to 2014, are comparable to the reported prevalence by Meinow et al. [1]. Although the prevalence of geriatric syndromes did not increase, the proportion of older people presenting these

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conditions revealed an ongoing increase, and this percentage is expected to rise over time.

Th e fi ndings reported in chapter 3 reveal that fi nancial stress is strongly associated with the presence of geriatric syndromes among older people. Earlier studies have identifi ed other factors indicative of low social position, such as primary education or low income, to be associated with the presence of complex health conditions experienced in old age [2–5]. Studies on specifi c geriatric syndromes, for example, cognitive impairment and falls, have also revealed an association with fi nancial stress and other income-related factors [6,7]. Th is association may be attributed to various mechanisms. For instance, high-risk health behaviors, which were found to be clustered among people whose social positions were relatively low, may contribute to the presentation of geriatric syndromes [8]. Limited social participation and other living conditions linked to fi nancial hardship are also known to be associated with geriatric syndromes [9,10]. However, when health-risk behaviors and factors relating to social activities were considered, fi nancial stress remained strongly associated with the presence of geriatric syndromes among older community-dwellers. Given the relatively low fi nancial burden entailed in accessing healthcare in Sweden, the costs of healthcare may only partly explain this association, which may also be linked to the direct impacts of stress induced by fi nancial hardship on geriatric syndromes. Some geriatric syndromes, such as depressive symptoms or falls, have been found to be associated with stress responses that may also stem from fi nancial diffi culties [11–13]. Stress itself, particularly if prolonged, may contribute to the wear and tear associated with aging, and may even accelerate aging processes associated with geriatric syndromes [14,15].

In addition, the results of this study have shown that older people born outside the Nordic countries had a higher prevalence of geriatric syndromes compared with those born in Nordic countries. Earlier studies have also shown that foreign-born individuals are less likely to avail of hospital care compared with native-born older people [16]. Th is association may be related to higher physical vulnerability [17], diff erences in the management of health conditions, health illiteracy, and lower use of in-hospital care [16]. However, lower income levels may also partially explain this fi nding [17,18]. A study from the Netherlands showed that older migrants from non-Western backgrounds were more likely to present geriatric syndromes

related to cognitive impairment [19]. Lower cognitive reserves associated with fewer years of education or lower social positions may also partially explain the higher prevalence of cognitive impairment among foreign-born older individuals [20]. The strain of financial difficulties stemming from a lower social position can also contribute to aging-related mechanisms [14,21,22]. In recent years, both the Netherlands and Sweden have experienced an influx of people with migrant backgrounds, who may be particularly vulnerable to geriatric syndromes in the future. For preventative reasons it may be relevant to pay extra attention to this part of the population in Sweden and The Netherlands.

Geriatric syndromes, physical activity, and chronic health conditions

Previous studies have pointed to geriatric syndromes as indicators of advanced aging-related impairments that need to be comprehensively assessed, as they are associated with an increased risk for hospitalization and mortality [23–25]. Our findings show that older people with geriatric syndromes may require increased care and attention, as geriatric syndromes are associated with declining or low physical activity and the subsequent development of chronic health conditions (see Fig. 5).

Studies have revealed the heterogeneity of physical activity patterns over time among older people [26–28]. With increasing age, there is a decline in physical activity patterns of older people [26]. Engagement in physical activity may be more difficult at an older age, as physical strength decreases and the presence of health conditions, notably cardiovascular diseases may hamper activity [26]. Health behavioral factors, such as smoking or increased alcohol intake, or a low socioeconomic background are known to be associated with declining trajectories of physical activity among older people [28]. However, our findings indicate that geriatric syndromes, particularly those that co-occur (i.e. the simultaneous presence of two or more) are also associated with declining or low physical activity trajectories over time.

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Health outcomes Health status Health behaviors

Physical activity

Chronic health conditions Aging / underlying dysfunctions

Mortality Hospitalization Geriatric syndromes Incontinence Vision and hearing

impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy

Fig. 4. Geriatric syndromes, physical activity and chronic health conditions Fig. 5. Geriatric syndromes, physical activity, and health conditions

Th e presence of two or more geriatric syndromes, can present as multiple organic impairments that hinder engagement in physical activity. Diff erent mechanisms may explain or account for this association. For instance, the presence of two or more geriatric syndromes may indicate not only advanced and accumulated impairments stemming from aging but also underlying disease-related pathophysiological processes [29,30].Th us, geriatric syndromes may refl ect the continued accumulation of impairments that eventually lead to the presentation of specifi c diseases that hinder physical activity [29]. Chapter 5 showed that

geriatric syndromes are associated with the development of chronic health conditions.Geriatric syndromes, such as falls or urinary incontinence, can directly affect participation in physical activity, for example, through the fear of falling or the need for close proximity to sanitary equipment [31]. This may decrease the engagement in physical activity a health protective measures, and thereby increase the risk for developing chronic health conditions.

Older respondents reported the presence of geriatric syndromes in relation to all of the identified trajectories of physical activity—high-stable, moderate-decreasing, low-increasing, and low stable. However, those with geriatric syndromes at baseline still demonstrated an increasing physical activity trajectory. An increase in physical activity among older people is also known to improve physical strength and cognitive abilities. Through their engagement in physical activity, older individuals maintain their independence and decrease their risks for institutionalization, hospitalization, and mortality [29,32,33]. Thus, geriatric syndromes may serve as target to increase or at least interfere with the decline in physical activity.

Geriatric syndromes are not only associated with low and decreasing levels of physical activity but are also associated with subsequent incidences of chronic health conditions, especially cardiovascular conditions and diabetes. Studies have shown that geriatric syndromes and chronic conditions such as cardiovascular disease are associated with aging-related processes [34,35]. Aging-related processes may contribute to changes in various organs that eventually present as geriatric syndromes [36]. These aging-related changes contribute to other pathophysiological processes in specific organs that may develop into chronic health conditions, for example an increase in inflammatory processes within the cardiovascular system [34]. Geriatric syndromes may thus be the first indication of underlying aging-related dysfunction that over time contributes to the incidence of chronic health conditions. Such processes may shed light on the finding of an association between geriatric syndromes and any chronic health condition, and specifically their association with cardiovascular diseases and diabetes, described in this thesis.

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Geriatric syndromes were found to be longitudinally associated with cardiovascular diseases and diabetes but not with other chronic health conditions. This finding may be associated with a lack of power in the study, as only a limited number of respondents reported specific chronic health conditions. Previous studies have revealed cross-sectional associations between geriatric syndromes and chronic health conditions such as COPD or dementia [37]. The association between geriatric syndromes and cancer may be more complex. While aging-related cell senescence can halt the proliferation of damaged DNA, it is also known to promote malignant transformation [37,38]. Thus, an association between geriatric syndromes and cancer may depend on other factors, including the specific organ or tissue affected [38].

Part II: Polypharmacy, falls, and health outcomes

Associations among polypharmacy and falls and hospitalization and mortality due to unintentional poisoning

Multimorbidity (i.e., multiple health conditions) occurring with old age contributes to increased use of medication [39]. Polypharmacy, or the intake of several medications concurrently, while being externally induced compared with other common geriatric syndromes, is also related to impairments in various organs systems occurring alongside the aging process [39]. Polypharmacy, entailing the ingestion of five or more medications that are often prescribed or dispensed, is associated with severe health outcomes, notably hospitalization and mortality [40,41]. Polypharmacy may also include the use of inappropriate drugs (i.e. those considered unsuitable for treatment) among older people [41–44]. The findings reported in this thesis indicate that older people taking three or more (less than the number of medications noted in the above definition of polypharmacy) have increased risks for hospitalization and mortality due to adverse drug events by unintentional poisoning.

Health outcomes Aging / underlying dysfunctions Mortality Hospitalization Geriatric syndromes Incontinence Vision and hearing_impairments

Depressive

symptoms Sleep problems

Frailty _impairmentCognitive

Falls Polypharmacy

Fig. 5. Associations between polypharmacy and falls and hospitalization and mortality due to unintentional poisoning

Fig. 6. Associations between polypharmacy and falls and hospitalization and mortality by unintentional poisoning

Th e above fi ndings may in part be explained by the ingestion of drugs known to be inappropriate for use by older individuals because of drug–drug or drug– disease interactions [45–47]. However, even when inappropriate medications were taken into account, older individuals receiving three or more medications still had an increased risk for hospitalization and mortality due to adverse drug events. Th e presence of cognitive or vision impairments, for example, could lead to the accidental intake of the wrong medication or incorrect dosages [48]. In addition, older people tend to use a variety of over-the-counter medications that could further augment the risk of drug–drug interactions [49]. Aging-related

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changes, such as metabolic changes, not only alter drug clearance processes, but they also lead to changes in adipose tissue deposition that alter the bioavailability and effects of medications among older people [50]. Aging-related physiological changes may play an important role in the association between large numbers of medications and hospitalization and mortality due to adverse drug events among older people. The interactions between aging-related changes and the use of a large number of medications may also contribute to the presentation of other geriatric syndromes such as falls.

The findings reported in this thesis show that an injurious fall among older individuals increases their risk for subsequent hospitalization or mortality due to an adverse drug event by unintentional poisoning. A fall can, on its own, be an indicator of an adverse drug event and may therefore be indicative of drug– drug interactions or side-effects [51]. In this study, older individuals who had experienced falls that led to hospitalization or mortality due to adverse drug events tended to receive more opioid analgesic medications than those who did not experience a subsequent adverse drug event. A fall may occur as aging-related changes interact with pharmacological effects associated with the ingestion of a large number of medications [39,43,52,53]. Additional medications taken after a fall may also account for the association between falls and subsequent hospitalization and mortality due to adverse drug events. The use of new medications after an incident, such as a fall, may also contribute to a prescribing cascade in which new medications are prescribed after other adverse events have occurred [54]. The presentation of a geriatric syndrome, such as a fall, thus requires a thorough assessment, as it not only relates to aging-related changes but it may also be induced by external factors like intake of large number of medications, which can be addressed.

Further research is needed to disentangle the associations between falls, polypharmacy, and other geriatric syndromes among older people. The presence of geriatric syndromes, particularly polypharmacy and falls, may serve as markers for interventions such as medical and pharmaceutical assessments, aimed at preventing harmful medication-related outcomes.

Studies conducted in Sweden and in the Netherlands

Cohort data from Sweden and the Netherlands were used for all of the studies reported in this thesis. Common characteristics of these countries are the high life expectancies and increasing proportions of older people within their populations [55]. In addition, the uses of healthcare facilities by older people with complex health conditions are comparable in Sweden, the Netherlands, and other European countries [56].

Some differences, however, require emphasis when considering geriatric syndromes and health in both contexts, as noted below.

The system for monitoring the impacts of policies on the health of older people is particularly advanced in the Netherlands [57]. This process entails assessment and continuous adaptation of policies focusing not only on older individuals’ fitness and health and their physical activity but also on their social and work participation [57]. Sweden has only recently strengthened processes for monitoring the impacts of relevant policies on the care of the elderly, which is predominantly managed at the municipal level [58]. The promotion of physical and social activities and the adaptation of these policies may help to delay and prevent geriatric syndromes within the older population segment.

A second difference relates to the retirement age in the two countries. Whereas the retirement ages stated in policies in Sweden and the Netherlands are comparable, the actual age of retirement in these countries differ [59]. In Sweden, men and women effectively work up to the ages of 66.4 and 65.0 years, respectively, whereas comparable ages in the Netherlands are 65.0 and 62.5 years, respectively [59]. Retirement has a significant effect on an individual’s health. For example, it has been shown that decline in musculoskeletal function increases prior to retirement, but that this decline decreases after retirement[60]. Older people retiring earlier may just benefit from this slowing in musculoskeletal function decline. The differences in the actual retirement ages in Sweden and the Netherlands may thus impact on the health of older individuals and the prevalence of geriatric syndromes in these countries.

Climate-related differences, such as less daylight during winter and more icy conditions, may also induce specific differences relating to the presence of specific geriatric syndromes in these countries. Seasonality and the extended winter

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months can contribute to the presentation of depressive symptoms, particularly in Sweden [61]. Exposure to settings such as snow and icy walkways in Sweden could also increase the risk for falls [62]. Thus, specific geriatric syndromes, such as falls and depressive symptoms, can vary in their prevalence in these countries and may require differential assessments.

Conceptual considerations

There is still a lack of consensus on the definition of geriatric syndromes. Therefore, the findings of studies on the geriatric syndromes considered in this thesis may differ to those of comparable studies [63–66]. Some geriatric syndromes, such as frailty, sarcopenia, and functional decline/impairment, may even overlap in their definitions, leading to different geriatric syndromes stated in other studies [67]. The selection of some geriatric syndromes as opposed to others in studies is limited by the lack of an all-encompassing definition and the availability of data [36].

The majority of studies reported in this thesis entailed the use of self-reporting for assessing geriatric syndromes. Alternative methods, such as consulting registers of health-conditions, do not adequately capture all of the existing geriatric syndromes, for example, frailty, as they primarily code for diagnosed diseases [68]. However, the International Statistical Classification of Diseases and Related Health Problems (ICD), which is often used in health registers, does code for some geriatric syndromes, for example, falls [68].

In these studies, depending on data availability, those syndromes fulfilling the definition of a geriatric syndrome set out in the introduction were considered. In addition, geriatric syndromes that are widely agreed upon and have been referenced in various studies [29,36,63,69,70] were considered.

Methodological considerations

This section presents a discussion on the methodologies applied in the studies described in this thesis that encompasses study samples and the measurement of geriatric syndromes, covariates, and outcomes.

Study populations

Data used for the studies described in this thesis were derived from three different sources and two countries, namely Sweden and the Netherlands. For the Swedish studies (see chapters 2 and 3), data were obtained from the Stockholm County Council Public Health Surveys and linked with the Swedish administrative registers. Data used in the studies described in chapters 6 and 7 were also obtained from these registers. The Dutch studies reported in chapters 4 and 5 were based on data obtained from participants in the Lifelines Cohort Study (Lifelines) from the three northern provinces in the Netherlands. The samples were large for all of the datasets, enabling cross-sectional and longitudinal analysis.

The Stockholm County Council Public Health Surveys covered a total of 50,000 individuals for each survey year and were conducted every four years. The participation rates of older people aged 65–84 years included in the studies (n = 18,592) were 74.5% (2006), 74.1% (2010), and 60.1% (2014). The survey cohort was found to be representative of the older cohort within the Swedish population in terms of morbidity [71]. However, very old people, those with physical and mental impairments, as well as those born outside of Sweden may have been underrepresented in the study sample because of health or language barriers [71]. Translation assistance was, however, provided during later surveys [72,73]. The Stockholm County Council Public Health Surveys focused on individuals living in the Stockholm catchment area. Therefore, it is possible that the results obtained for older people in the Stockholm area may not have been representative in terms of older people living outside of Stockholm.

The Swedish administrative registers, namely the Swedish Patient, Cause of Death, and Swedish Prescribed Drug registers contain a large proportion of the healthcare information for the Swedish population relating to hospitals, all deaths, and dispensed medications (n > 9,000,000), respectively. Consequently, it was possible to analyze specific geriatric syndromes such as polypharmacy and

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injurious falls among older people. The results can be considered representative of the entire population [74]. The use of these registers limits recall bias, as diagnosis are directly recorded. Medical diagnoses recorded in the registers were dependent on the diagnoses provided by physicians, and inaccuracies cannot be ruled out, particularly for older individuals with multiple health conditions, necessitating the coding and registration of multiple diagnoses [75,76].

Data obtained from the Lifelines Cohort Study comprised mainly participants’ responses to questionnaires relating to sociodemographic, social, health, and health-related factors. Recruitment of participants was predominantly done via general practitioners but also via family members. The response rate for the follow-up measures was around 60%. The participation rate of individuals enrolled by their general practitioners was low, which could have led to healthy selection bias. Physical activity levels of older individuals tended to be slightly higher than those reported for older individuals within the Dutch population, that is, 62% of older people in the Lifelines study were active for at least five days in a week compared with 44% in the Dutch population [77].

Quality of data

Cross-sectional and longitudinal data were used to examine geriatric syndromes and associated factors in the studies reported in this thesis. The following sections present a discussion on the quality of the data on geriatric syndromes and all of the factors considered in the different studies.

Geriatric syndromes

As self-reported data were used to measure geriatric syndromes, misclassifications cannot be discounted. In cases of self-reported information on geriatric syndromes discussed in chapters 2, 3, 4, and 5, it is possible that the prevalence of geriatric syndromes was underestimated as a result of recall bias or (fear of) stigmatization. Older people with geriatric syndromes tend to be more prone to ill-health. Therefore, recall bias or (fear of) stigmatization may have also led to the underestimation of the associations of geriatric syndromes with declining physical activity and the development of chronic health conditions discussed in chapters 4 and 5. In addition, specific geriatric syndromes, for example, falls were assessed using different questions in the Stockholm County Council Public Health Surveys and in the Lifelines Cohort study. The questions used in the former study

covered any falls that had occurred in the last months at the time of questioning, whereas the question used in the latter study focused on falls that occurred along with dizziness. This difference may explain variations in the prevalence of geriatric syndromes observed in the studies, making direct comparisons between the Swedish and Dutch data difficult.

Chapters 6 and 7 present assessments of specific geriatric syndromes, namely falls and polypharmacy that were assessed using Swedish administrative registers. The use of these registers, which provide precise and continuously updated data, was advantageous [74,78]. Their use reduced the risk of recall bias. However, there were also some limitations. Over-the-counter medications were not considered in the assessment presented in chapter 6, which may have contributed to potential overestimation in the reported results. Furthermore, only information on dispensed medication was available; information on whether or not medications were actually consumed was not recorded. Of the fall cases examined in chapter 7, only severe fall injuries (i.e., those requiring hospital admissions) were considered. Less severe falls were not captured in the analysis. Moreover, older individuals who experience falls requiring hospitalization may be more fragile. It is possible that the association between falls and hospitalization and mortality by unintentional poisoning may have been partially overestimated, as only severe falls often requiring new medication prescriptions were considered

Social position, physical activity, chronic health conditions, and adverse drug events by unintentional poisoning

Misclassifications of some of the social position measures used in the studies reported in chapters 2 and 3 were limited, as the relevant data were extracted from Swedish administrative registers. Measures such as education level, country of origin, and civil status were based on entries extracted from these registers and were linked through Swedish individuals’ identification numbers.

Wealth-related factors, notably financial stress and type of accommodation were based on self-reporting, which could have been influenced by recall bias as well as the issue of social stigma. The results obtained on the association between financial stress and geriatric syndromes may have been underestimated, as fewer older people may have reported financial stress as a result of social stigma.

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Health behavioral factors measured as covariates, as discussed in chapters 2, 3, and 5, and as outcomes (chapter 4), may also have been subject to information bias. Misclassification of smoking status, alcohol consumption, and physical activity may have occurred as a result of more favorable self-reporting that could have contributed to underestimation of smoking status and alcohol consumption. Data on physical activity obtained in the Lifelines Cohort Study, discussed in chapter 4, were based on self-reporting of the number of physically active days. Physical activity was then assessed at baseline and through three follow-up measurements. For the fourth measurement, the participants were asked about their physical activity levels in the summer and in the winter, and the average was taken as the measure. This measure could have led to misclassification depending on the season in which the questionnaire was completed, but it would have had a non-differential effect on the association. Loss of follow-up and exclusion of participants who did not answer at least three questionnaires on physical activity may have led to overestimation of physical activity levels. This issue may have contributed to underestimations of the associations between geriatric syndromes and moderate-declining and low-stable physical activity trajectories, as older individuals with poorer health engaging in low levels of physical activity may have been excluded. The presence and development of chronic health conditions, discussed in chapter 5, were determined through participants’ self-reporting. The exclusion of individuals with cardiovascular diseases, pulmonary diseases (COPD, asthma, chronic bronchitis, and emphysema), cancer, neurological diseases (Parkinson’s disease and dementia), and diabetes was based on self-reported information validated by medication use [79]. Self-reports on chronic health conditions were used for each of the four measurement points. These self-reported data could have been subject to recall bias, which, in turn, could have affected the incidence of the chronic health conditions under investigation. However, studies have shown that self-reporting of the presence of diseases by older individuals is broadly representative of their health status [80,81].

Attribution of causality and confounding factors Causality

Cross-sectional and longitudinal data from different sources were used for the studies. Chapters 2 and 3 employed cross-sectional study designs. The nature of the questions implies some directionality (i.e., education completed early in life)

and the presence of geriatric syndromes (e.g., recent falls that occurred in the last six months).

Utilization of registers and of a longitudinal design reduced the risk of reverse causation in the studies described in chapters 4, 5, 6, and 7. Longitudinal data obtained from the Lifelines Cohort Study were used for the studies reported in chapters 4 and 5. The longitudinal design enabled analyses of the associations between geriatric syndromes at baseline and trajectories of physical activity as well as the development of chronic health conditions over a period of several years. It is possible that some reverse causation existed between geriatric syndromes and physical activity (chapter 4). Both geriatric syndromes and physical activity were measured at the baseline. However, physical activity levels were followed over three additional measures, which would have limited the possibility of reverse causation.

Given the nature of the design of all of the studies, causal interference cannot be assumed.

Confounding factors

All of the analyses were adjusted for age and sex. In some instances, stratification was conducted to enable further assessment of the effects by age and sex. Residual confounding may have been limited in most of the studies, as the assessed cohorts and the registries used in the studies provided data across a variety of domains, such as sociodemographic attributes, health behaviors, and health conditions. Confounding factors, such as risky health behaviors, may not have been captured in the studies presented in chapters 6 and 7 because of non-availability of data. It is likely that these behaviors would explain some of the observed associations. Accounting for risky health behaviors could decrease the strength of the association between falls and number of medications and the assessed outcome. Similarly, limited or missing information on nutrition in the studies could have partially confounded the associations between geriatric syndromes and other outcomes.

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Implications of the findings

The findings presented in this thesis have implications for medical and global public health research, policy, and practice, as discussed below.

Implications for future research

In 1965, Bernard Isaacs coined the term “geriatric giants,” encompassing immobility, instability, incontinence, and impaired memory. Over time, the conceptualization of and research on these common aging-dependent conditions among older people have advanced. In 1991, Fried and colleagues conducted further research on aging-related conditions. Their focus was on conditions that are commonly experienced by older people but are rarely associated with one specific disease or underlying pathology [36,82]. Inouye and colleagues conceptualized the idea of prevalent syndromes among older individuals further [55], providing a basis for an increasing variety of research topics relating to geriatric syndromes [55]. This thesis confirms some of the points raised by Inouye et al. through investigations of geriatric syndromes and their association with social position and other chronic health conditions among older people in Sweden and the Netherlands. It incorporates current concepts relating to geriatric syndromes, while also identifying gaps that can be addressed in future research projects. Although studies on geriatric syndromes are increasing, a consistent definition on conditions considered to be geriatric syndromes is still lacking. The studies presented here have focused on the geriatric syndromes most commonly referred to in the literature and those that are most prevalent among community-dwellers. However, a definition needs to be established to enable comparisons of findings derived from different studies conducted in different settings. A consistent definition of geriatric syndromes may also enable the development of assessment tools and questionnaires that could be applied in other studies [68].

The results of the cross-sectional study reported in chapter 2 revealed that social position is associated with geriatric syndromes. New studies adopting a life course approach may shed further light on how social position established in early childhood, or at other life stages, may lead to the development of geriatric syndromes at older ages. A life course approach may also help to determine the direction of the relationship between social position and geriatric syndromes [83].

Furthermore, new insights may facilitate the identification of intervention targets earlier in life.

In our longitudinal studies, we found that geriatric syndromes were associated with distinct trajectories of physical activity and with the development of specific chronic health conditions. Future research should be aimed at determining whether specific clusters of geriatric syndromes, such as urinary incontinence and falls, exist and their associations with outcomes that include physical activity and specific health conditions. Some clinical researchers have already identified clusters of geriatric syndromes and patterns of geriatric syndromes and chronic conditions [63,84]. Longitudinal studies conducted among older community-dwellers may help to disentangle more long-term associations between different geriatric syndromes and factors external to clinical settings. These studies could also focus on the multidirectional associations between geriatric syndromes and chronic health conditions in relation to underlying aging processes [85,86].

Implications for policy and practice

The studies reported in this thesis have shown that geriatric syndromes are associated with a progressive decline in physical activity, the development of chronic health conditions, and adverse health outcomes. However, they have also demonstrated that older individuals with geriatric syndromes can still engage in increased physical activity. Despite the complexity and breadth of geriatric syndromes, the presence of a geriatric syndrome does not necessarily mean that an older person will rapidly age and die. Geriatric syndromes may indicate underlying aging processes and can serve to indicate the need for focused care and assessments by physicians. Studies and clinical practice have introduced geriatric assessments or frailty indices that facilitate the identification of the most vulnerable individuals within the older population segment. However, identification of geriatric syndromes may serve as a targetable indicator for public health initiatives that can even be employed at general practice. Managing geriatric syndromes, such as urinary continence or polypharmacy, may enable older individuals to increase their physical activity levels or maintain their independence in old age.

Geriatric syndromes should be addressed within clinical practice and should be assessed beyond their presentation. An increasing number of studies are elucidating the underlying mechanisms that connect these syndromes to aging

8

[37]. Comprehensive assessments and regular screening of these syndromes would enable the documentation of declining health and physical activity and the development of chronic health conditions.

The provision of healthcare is becoming increasingly specialized, with a focus on specific diseases. However, geriatric syndromes are associated with impairments that affect various organ systems [23]. They are highly prevalent and increase the risk for decreased physical activity, hospitalization, and mortality [23,70]. Policies and efforts should therefore be implemented at the population level to detect geriatric syndromes at an early stage. By targeting specific groups of older individuals, for example, those with relatively low social positions who lack sufficient financial means, these policies and initiatives would have more impact by enabling the provision of additional medical as well as financial support for older individuals from specific groups or social backgrounds.

Conclusion

Geriatric syndromes are prevalent among older people. Not only low social position entailing limited financial means but also countries of origin and birth are associated with geriatric syndromes. The presence of geriatric syndromes increases the risk of declining physical activity and the development of chronic health conditions. In addition, geriatric syndromes, such as falls and polypharmacy, associated with the concomitant use of numerous medications can increase the risk for severe outcomes such as hospitalization and death caused by unintentional poisoning.

Comprehensive assessments and monitoring of geriatric syndromes within general practice and hospitals may help to prevent or delay the declining health of older people. Further longitudinal studies are needed to acquire a deeper understanding of the temporal relations among the geriatric syndromes themselves and their associations with other health conditions and diseases affecting older people.

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