Abstract
Background/Objectives
Geriatric syndromes are common in older women and contribute to disability risk. Little is known about how the number of geriatric syndromes is associated with incident disability in community-based populations of older adults.
Design
Longitudinal analysis from the Women’s Health Initiative Observational Study (WHI).
Setting
Community-based.
Participants
29,544 women aged 65 or older, who were enrolled in the WHI and free of disability in activities of daily living (ADL) at baseline.
Measurements
Geriatric syndromes were self-reported at baseline and three year follow-up and included high depressive symptoms, dizziness, falls, hearing or visual impairment, osteoporosis, polypharmacy, syncope, sleep disturbance, and urinary incontinence. Disability was defined as dependence in any ADL and was assessed at baseline and follow-up. Chronic diseases were measured by a modified Charlson index.
Results
Geriatric syndromes were common in this population of women; 76.3% had at least one syndrome present at baseline. Increased number of geriatric syndromes at baseline was significantly associated with increased risk of incident ADL disability at follow-up (p ≤ 0.001). The adjusted risk ratio (RR) and 95% confidence interval (CI) for a single syndrome compared to no syndromes was 1.21 (0.78, 1.87). For women with five or more geriatric syndromes, the RR (CI) was 6.64 (4.15, 10.62). These results were only slightly attenuated after adjustment for number of chronic diseases or pain.
Conclusion
Geriatric syndromes are significantly associated with onset of disability in older women; this association is not simply a result of chronic disease or pain. A better understanding of how these conditions contribute to disablement is needed. Geriatric syndrome assessment should be considered along with chronic disease management in the prevention of disability in older women.
Keywords: Geriatric syndromes, disability, aging, women’s health
INTRODUCTION
Disability in the elderly is an important and growing public health concern. Disability results in higher usage of medical care, increased institutionalization, and poorer physical and mental health 1–3. Approximately 9% of the US population over 65 years of age has one or more disabilities in basic Activities of Daily Living (ADLs)4. Identifying contributors to disability onset is important in prevention, but identification is complicated by the complexity of multiple co-morbidities and risk factors which are the norm rather than the exception in older patients 5. The presence of multiple disease states leads to increased vulnerability to stressors and consequently to higher rates of disability in this population 2. Though often ignored when assessing elders’ risk of disablement, geriatric syndromes may be as important as clinically-recognized diseases in determining disability 4–6. Failure to account for geriatric syndromes may lead to an incomplete understanding of how pathology progresses to disability 3.
Geriatric syndromes are a loosely-defined group of conditions that are common in the geriatric population and are often the result of cumulative insults to multiple organ systems4, 5. There is no consensus as to which conditions to consider as geriatric syndromes, but falls, incontinence, depressive symptoms, cognitive impairment, dizziness, and sensory impairment are often included4, 5, 7. Geriatric syndromes often co-occur with each other and with other chronic medical conditions 4, 6, 8 and share numerous overlapping pathways and risk factors 5, 7, 9. In addition, geriatric syndromes may occur as a result of a chronic disease or its treatment 10, 11.
Geriatric syndromes arise from multifactorial impairments of bodily systems 5. Presence of multiple geriatric syndromes may indicate a general phenotype of vulnerability whereas those occurring in isolation may be more localized in their etiology. Geriatric syndromes are related to, but distinct from, disability, which is commonly defined as difficulty in carrying out usual activities due to a physical or mental health limitation3. The disablement process describes the way in which pathology due to disease or injury may develop into disability when risk factors are present 3. Geriatric syndromes likely play a role in the disablement process, but the nature of that role is not clear. The physiologic vulnerability that under lies on set of geriatric syndromes may also increase susceptibility to disability; alternatively, geriatric syndromes may be a direct risk factor for disability12.
While two cross-sectional studies support a relation between multiple geriatric syndromes and disability 4, 6, longitudinal studies are needed to assess the impact of total number of geriatric syndromes on incident disability. Although this relation is likely bi-directional, longitudinal assessment can demonstrate that geriatric syndromes are not simply a consequence of disability but can precede and potentially contribute to disability onset.
This study was designed to examine the association of the number of baseline geriatric syndromes with incident disability in activities of daily living at three years among community-dwelling women aged 65 years and older. We hypothesized that risk for disability increases with an increasing number of geriatric syndromes and that this association is not simply a consequence of the association of geriatric syndromes with chronic diseases or pain.
METHODS
Study population
The WHI enrolled 93,676 women aged 50–79 years into an observational study (details previously published 13). Women were recruited at 40 clinical centers across the United States from 1994 to 1998 through community-based methods 14. Exclusion criteria for the WHI were minimal and included the presence of conditions with predicted survival of less than 3 years, or those that would interfere with compliance, such as substance abuse 13. All women provided informed consent prior to participation. The current analysis was approved by the Drexel University Institutional Review Board.
Women aged 65 years and older were included in these analyses (n=43,599). Women who died by follow-up (n=1,276) were not included in these analyses. In addition, women were excluded if they had missing data on baseline (n=1,600) or three year (n=4,081) ADLs, or on any geriatric syndromes (n=2,176). Women with any ADL disability at baseline (n=874) also were excluded. To avoid possible confounding due to the strong association of cancer and its treatment with geriatric syndromes and with disability15, 16, women with history of cancer at baseline or a cancer diagnosis during the follow-up period also were excluded (n=8,262). Women excluded from these analyses were older (p<0.001), had more geriatric syndromes (p<0.001), and were more likely to be non-white (p<0.001), less educated (p<0.001), lower income (p<0.001), and to be current or former smokers (p<0.001), compared to the general WHI population 65 years and older.
Geriatric Syndromes
All geriatric syndromes were assessed at baseline and three year follow-up by self-report questionnaires. Geriatric syndromes were selected for consideration in this study based on common definitions of geriatric syndromes and data availability4, 5, 8.
Depressive symptoms were measured by the shortened CES-D/DIS screening instrument with a cut-off of 0.06 used to identify those meeting criteria for high depressive symptoms 17.
Presence and severity of any dizziness was self-reported over the previous four weeks. Any reported dizziness was considered as a geriatric syndrome here.
Any trouble in hearing and vision were assessed over the previous four weeks and were considered as separate geriatric syndromes. Trouble with vision was specified as any trouble seeing that was uncorrected by lenses.
Women were asked how many times they had fallen and landed on the floor or ground in the past year and were defined as fallers if they reported at least two falls in the previous year.
Osteoporosis was defined as ever having been told by a doctor that they had the condition.
Polypharmacy was defined here as current use of five or more prescription and over the counter medications based on in-person medication review18.
Sleep disturbance was defined as five or fewer hours’ reported sleep on a typical night in the past four weeks19.
Syncope was self-reported as having fainted, blacked out, passed out, or lost consciousness in the past twelve months.
Urinary incontinence (UI) was defined here as having urine leakage at least once per week in the past year 9.
Disability
Disability was measured by four activities of daily living (ADL). ADLs included eating, dressing, getting in and out of bed, and taking a bath or shower 20. For each, participants were asked if they could do it without help (score=1), with some help (score=2), or if they were unable to complete the activity (score=3). Scores were summed for all activities with a score of 4 indicating independence in all activities and higher scores indicating greater ADL disability. The ADL construct was assessed at baseline and at year three. Incident disability was defined as having at least one ADL disability at the year three visit.
Covariates
Demographic variables were recorded at either the screening or baseline visit. Age was reported to the nearest year. Self-reported race/ethnicity, current marital status, educational achievement, income and smoking status were categorized as shown in Table 1. Number of chronic diseases was quantified according to a modified Charlson Index 21. This included self-report at baseline of: congestive heart failure, diabetes, myocardial infarction, peripheral artery disease, stroke, transient ischemic attacks, Alzheimer’s disease, arthritis, stomach ulcers, liver disease, asthma and emphysema. The total number of these diseases was calculated to obtain a Charlson score for each individual at baseline. The Charlson score was updated for incidence of disease by year three follow-up. Pain was assessed at baseline and at year three follow-up by the Bodily Pain subscale of the SF-36 which includes questions determining amount of bodily pain over the past four weeks and extent to which pain interfered with one’s normal work 22. These were each coded from 0–100 and then averaged together to obtain a single score with 100 indicating no pain and 0 indicating severe pain with extreme interference.
Table 1.
Baseline characteristics of women aged 65 years and older from the Women’s Health Initiative Observational Study by number of geriatric syndromes (GS)*
| Total (n=29544) | 0 GS (n=6771) | 1 GS (n=8586) | 2 GS (n=6635) | 3 GS (n=3718) | 4 GS (n=1780) | 5+ GS (n=1040) | |
|---|---|---|---|---|---|---|---|
| Prevalence (%) | 23.7 | 30.1 | 23.3 | 13.0 | 6.2 | 3.7 | |
| Mean (SD) Age (years) | 70.1 (3.7) | 69.5 (3.5) | 70.0 (3.6) | 70.2 (3.7) | 70.6 (3.8) | 70.8 (3.8) | 71.0 (3.9) |
| Mean (SD) Charlson score | 0.95 (0.90) | 0.67 (0.74) | 0.84 (0.81) | 1.02 (0.90) | 1.16 (0.95) | 1.34 (1.00) | 1.60 (1.12) |
| Mean (SD) Pain score | 74.9 (23.0) | 83.6 (18.1) | 78.2 (20.9) | 72.9 (22.9) | 67.7 (24.1) | 61.9 (24.9) | 53.2 (25.9) |
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
|
| |||||||
| Race | |||||||
| Caucasian | 25802 (87.6) | 5897 (87.5) | 7545 (88.1) | 5814 (87.9) | 3282 (88.6) | 1576 (89.0) | 898 (86.5) |
| African American | 1584 (5.4) | 360 (5.3) | 436 (5.1) | 346 (5.2) | 189 (5.1) | 88 (5.0) | 54 (5.2) |
| Hispanic | 668 (2.3) | 129 (1.9) | 176 (2.1) | 142 (2.2) | 71 (1.9) | 47 (2.7) | 39 (3.8) |
| Asian | 954 (3.2) | 253 (3.8) | 299 (3.5) | 203 (3.1) | 121 (3.3) | 36 (2.0) | 15 (1.5) |
| American Indian | 91 (0.3) | 18 (0.3) | 18 (0.2) | 25 (0.4) | 14 (0.4) | 6 (0.3) | 6 (0.6) |
| Other | 349 (1.2) | 84 (1.3) | 95 (1.1) | 86 (1.3) | 29 (0.8) | 18 (1.0) | 26 (2.5) |
| Marital Status | |||||||
| Never Married | 1170 (4.0) | 284 (4.2) | 338 (4.0) | 260 (3.9) | 140 (3.8) | 83 (4.7) | 25 (2.4) |
| Divorced/Separated | 3530 (12.0) | 810 (12.0) | 977 (11.4) | 771 (11.7) | 462 (12.5) | 223 (12.6) | 145 (14.0) |
| Widowed | 7804 (26.5) | 1575 (23.4) | 2194 (25.7) | 1820 (27.5) | 1053 (28.4) | 514 (29.0) | 338 (32.6) |
| Married/ Cohabitating | 16917 (57.5) | 4076 (60.4) | 5042 (59.0) | 3758 (56.9) | 2049 (55.3) | 951 (53.7) | 529 (51.0) |
| Education | |||||||
| < High school | 1594 (5.4) | 259 (3.9) | 399 (4.7) | 351 (5.3) | 242 (6.6) | 131 (7.4) | 97 (9.4) |
| High school diploma | 5322 (18.1) | 1187 (17.7) | 1517 (17.8) | 1211 (18.4) | 675 (18.3) | 319 (18.0) | 215 (20.9) |
| Some college or technical school | 11003 (37.5) | 2418 (36.0) | 3239 (38.0) | 2506 (38.0) | 1366 (37.0) | 710 (40.1) | 406 (39.4) |
| College degree | 3337 (11.4) | 859 (12.8) | 1010 (11.8) | 737 (11.2) | 387 (10.5) | 166 (9.4) | 84 (8.2) |
| Post-graduate degree | 8088 (27.6) | 2000 (29.8) | 2369 (27.8) | 1783 (27.1) | 1026 (27.8) | 444 (25.1) | 229 (22.2) |
| Income | |||||||
| < $50,000 | 19104 (70.5) | 4131 (66.7) | 5423 (68.6) | 4388 (71.9) | 2483 (72.4) | 1259 (77.2) | 776 (81.6) |
| $50–74,999 | 4512 (16.7) | 1133 (18.3) | 1397 (17.7) | 968 (15.9) | 565 (16.5) | 217 (13.3) | 103 (10.8) |
| $75–99,999 | 1763 (6.5) | 479 (7.7) | 544 (6.9) | 366 (6.0) | 195 (5.7) | 88 (5.4) | 39 (4.1) |
| > $100,000 | 1709 (6.3) | 452 (7.3) | 538 (6.8) | 382 (6.3) | 185 (5.4) | 66 (4.1) | 33 (3.5) |
| Smoking | |||||||
| Never | 15820 (54.3) | 3784 (56.5) | 4597 (54.3) | 3477 (53.1) | 1924 (52.4) | 931 (52.9) | 578 (56.4) |
| Former | 12062 (41.4) | 2606 (38.9) | 3503 (41.3) | 2810 (42.9) | 1609 (43.8) | 750 (42.6) | 397 (38.7) |
| Current | 1252 (4.3) | 306 (4.6) | 373 (4.4) | 260 (4.0) | 142 (3.9) | 78 (4.4) | 50 (4.9) |
includes total number of high depressive symptoms, dizziness, falls, hearing impairment, osteoporosis, polypharmacy, sleep disturbance, syncope, urinary incontinence, and visual impairment
all p-values comparing across number of geriatric syndromes are <0.001
Statistical Analysis
Mean number of geriatric syndromes at baseline and year three were compared using paired t-tests. Co-occurrence and 95% confidence intervals (CI) of geriatric syndromes were calculated using binomial proportions. Log binomial regression was used to calculate risk ratios (RR) and 95% CIs for incident disability. Backward selection based on statistical significance (p≤0.1) of the covariate was used to build the regression models beginning with the least significant covariates and continuing until all remaining covariates were statistically significantly associated with the outcome. All eliminated covariates were reintroduced individually into the model and those that changed the main effect estimate by 10% or more were retained in the final model 23. Based on backward selection, all models were adjusted for age, smoking and income. Additional models were adjusted for Charlson or pain scores. Additional log binomial regression analyses were conducted using year three follow-up information for geriatric syndrome number with and without the updated Charlson or pain scores. All analyses were performed in SAS 9.2.
RESULTS
A total of 29,544 women were included in these analyses. Women with more geriatric syndromes at baseline were, on average, older, more likely to have chronic diseases, less likely to be married, less educated, and more likely to have lower income than women with fewer geriatric syndromes (all p ≤ 0.001; Table 1).
Geriatric syndromes at baseline were common; 76.3% of women had at least one syndrome (Table 1). For those with four or fewer geriatric syndromes, hearing impairment and urinary incontinence were the most common syndromes (Table 2). Approximately three quarters of women who had five or more geriatric syndromes had dizziness, urinary incontinence, hearing impairment or visual impairment. Co-occurrence of individual geriatric syndromes is shown in Table 3. Mean Charlson score increased and mean pain score decreased (indicating more pain and pain interference)in a linear fashion as the number of geriatric syndromes increased (p ≤ 0.001; Table 1).
Table 2.
Baseline prevalence (percent) and 95% confidence interval (CI) of individual geriatric syndromes (GS) by GS total for women aged 65 years and older from the Women’s Health Initiative Observational Study at baseline.
| Total Prevalence (n=29544) | 1 GS (n=8586) | 2 GS (n=6635) | 3 GS (n=3718) | 4 GS (n=1780) | 5+ GS (n=1040) | |
|---|---|---|---|---|---|---|
|
| ||||||
| Prevalence (95% CI) | Prevalence (95% CI) | Prevalence (95% CI) | Prevalence (95% CI) | Prevalence (95% CI) | Prevalence (95% CI) | |
| Depressive symptoms | 8.0 (7.7, 8.3) | 3.4 (3.0, 3.8) | 8.2 (7.5, 8.9) | 14.4 (13.3, 15.6) | 24.5 (22.5, 26.5) | 44.5 (41.5, 47.5) |
| Dizziness | 18.6 (18.1, 19.0) | 9.0 (8.4, 9.6) | 21.3 (20.3, 22.3) | 36.8 (35.2, 38.3) | 53.1 (50.8, 55.4) | 74.5 (71.9, 77.2) |
| Falls | 11.3 (10.9, 11.6) | 5.8 (5.3, 6.3) | 13.2 (12.4, 14.0) | 21.4 (20.1, 22.7) | 30.7 (28.6, 32.9) | 46.7 (43.7, 49.8) |
| Hearing Impairment | 29.2 (28.6, 29.7) | 21.9 (21.0, 22.8) | 38.6 (37.4, 39.8) | 53.0 (51.4, 54.6) | 64.1 (61.9, 66.3) | 73.4 (70.7, 76.1) |
| Osteoporosis | 11.8 (11.4, 12.1) | 7.5 (6.9, 8.0) | 14.1 (13.3, 15.0) | 21.7 (20.4, 23.0) | 29.3 (27.2, 31.4) | 39.9 (36.9, 42.9) |
| Polypharmacy | 22.0 (21.6, 22.5) | 14.1 (13.4, 14.8) | 28.6 (27.5, 29.7) | 41.3 (39.8, 42.9) | 53.0 (50.7, 55.4) | 68.2 (65.3, 71.0) |
| Sleep Disturbance | 7.7 (7.4, 8.0) | 4.3 (3.9, 4.7) | 9.2 (8.5, 9.9) | 14.4 (13.3, 15.6) | 19.3 (17.4, 21.1) | 31.0 (28.2, 33.8) |
| Syncope | 2.4 (2.2, 2.6) | 1.0 (0.8, 1.2) | 2.4 (2.1, 2.8) | 4.3 (3.7, 5.0) | 7.8 (6.5, 9.0) | 13.7 (11.6, 15.7) |
| Urinary Incontinence | 29.3 (28.8, 29.9) | 22.3 (21.5, 23.2) | 39.3 (38.1, 40.4) | 52.9 (51.3, 54.5) | 62.6 (60.4, 64.9) | 73.8 (71.1, 76.4) |
| Visual Impairment | 20.5 (20.0, 20.9) | 10.7 (10.1, 11.4) | 25.1 (24.1, 26.1) | 39.7 (38.2, 41.3) | 55.6 (53.3, 57.9) | 74.3 (71.7, 77.0) |
Table 3.
Baseline prevalence (percent) and 95% confidence interval of individual geriatric syndromes (GS) among women aged 65 years and older from the Women’s Health Initiative Observational Study (n=29544). Table is to be read horizontally; for example, among women who had depressive symptoms, 32.3% also had dizziness.
| Depressive symptoms | Dizziness | Falls | Hearing Impairment | Osteoporosis | Polypharmacy | Sleep Disturbance | Syncope | UI | Visual Impairment | |
|---|---|---|---|---|---|---|---|---|---|---|
| Overall Prevalence | 8.0 (7.7, 8.3) | 18.6 (18.1, 19.0) | 11.3 (10.9, 11.6) | 29.2 (28.6, 29.7) | 11.8 (11.4, 12.1) | 22.0 (21.6, 22.5) | 7.7 (7.4, 8.0) | 2.4 (2.2, 2.6) | 29.3 (28.8, 29.9) | 20.5 (20.0, 20.9) |
|
| ||||||||||
| Depressive symptoms | -- | 32.3 (30.4, 34.2) | 16.6 (15.1, 18.1) | 35.2 (33.3, 37.2) | 14.5 (13.1, 15.9) | 31.2 (29.4, 33.1) | 18.0 (16.4, 19.5) | 3.9 (3.1, 4.7) | 37.5 (35.5, 39.4) | 33.0 (31.1, 34.9) |
| Dizziness | 13.9 (13.0, 14.9) | -- | 16.1 (15.1, 17.0) | 38.8 (37.5, 40.1) | 14.2 (13.3, 15.2) | 29.8 (28.5, 31.0) | 10.8 (10.0, 11.7) | 5.6 (5.0, 6.2) | 36.1 (34.8, 37.3) | 33.0 (31.7, 34.2) |
| Falls | 11.8 (10.7, 12.9) | 26.5 (25.0, 28.0) | -- | 34.8 (33.2, 36.5) | 15.2 (14.0, 16.4) | 27.7 (26.2, 29.2) | 9.7 (8.7, 10.8) | 6.0 (5.1, 6.8) | 38.1 (36.5, 39.8) | 28.3 (26.8, 29.9) |
| Hearing Impairment | 9.7 (9.1, 10.3) | 24.7 (23.8, 25.6) | 13.5 (12.7, 14.2) | -- | 13.6 (12.9, 14.3) | 24.9 (24.0, 25.8) | 8.5 (7.9, 9.1) | 2.4 (2.1, 2.7) | 34.1 (33.1, 35.2) | 29.2 (28.2, 30.1) |
| Osteoporosis | 9.9 (8.9, 10.9) | 22.6 (21.2, 24.1) | 14.7 (13.5, 15.8) | 33.9 (32.3, 35.5) | -- | 29.9 (28.4, 31.4) | 9.5 (8.5, 10.5) | 3.5 (2.9, 4.1) | 33.8 (32.2, 35.4) | 24.5 (23.0, 25.9) |
| Polypharmacy | 11.4 (10.6, 12.1) | 25.1 (24.0, 26.1) | 14.2 (13.3, 15.0) | 33.0 (31.8, 34.1) | 15.9 (15.0, 16.8) | -- | 8.5 (7.8, 9.2) | 3.3 (2.9, 3.8) | 37.7 (36.5, 38.9) | 26.0 (24.9, 27.0) |
| Sleep Disturbance | 18.7 (17.1, 20.3) | 26.2 (24.4, 28.0) | 14.2 (12.8, 15.7) | 32.3 (30.4, 34.2) | 14.5 (13.0, 15.9) | 24.3 (22.5, 26.0) | -- | 3.3 (2.6, 4.1) | 32.2 (30.3, 34.1) | 25.6 (23.8, 27.4) |
| Syncope | 13.0 (10.5, 15.5) | 43.2 (39.5, 46.8) | 27.8 (24.5, 31.1) | 28.7 (25.3, 32.0) | 16.8 (14.0, 20.0) | 30.4 (27.0, 33.8) | 10.6 (8.4, 12.9) | -- | 34.2 (30.7, 37.7) | 26.9 (23.6, 30.2) |
| Urinary Incontinence | 10.2 (9.6, 10.9) | 22.9 (22.0, 23.8) | 14.6 (13.9, 15.4) | 33.9 (32.9, 34.9) | 13.6 (12.8, 14.3) | 28.3 (27.3, 29.2) | 8.5 (7.9, 9.1) | 2.8 (2.5, 3.2) | -- | 24.6 (23.7, 25.5) |
| Visual Impairment | 12.9 (12.0, 13.7) | 29.8 (28.7, 31.0) | 15.6 (14.7, 16.5) | 41.5 (40.2, 42.7) | 14.0 (13.1, 14.9) | 27.9 (26.8, 29.1) | 9.6 (8.8, 10.3) | 3.2 (2.7, 3.6) | 35.3 (34.1, 36.5) | -- |
By the three-year follow-up visit, 742 (2.5%) women had developed ADL disability. Difficulty with showering was the most common disability (n=383; 1.3%). In addition, 210 (0.7%) women had difficulty eating, 201 (0.7%) women had difficulty dressing, and 158 (0.5%) women had difficulty getting in and out of bed. Only 150 (0.5%) women had disability in multiple domains at the three year follow-up. Scores on the ADL construct were generally low. Of those women with a disability at follow-up, 454 (61.2%) indicated need for assistance with one activity. In addition, 190 (25.6%) indicated either need for assistance on two activities or inability to complete one activity. Only 98 (13.2%) of women indicated having a higher level of disability.
Women with two or more geriatric syndromes at baseline had a greater risk of developing ADL disability over three years compared to women with no syndromes (Table 4). Risk of disability increased with increasing number of geriatric syndromes (test for trend: p<0.001). Women with a single geriatric syndrome were 1.21 (95% CI: 0.78–1.87) times as likely as those with no geriatric syndromes to become disabled by the three year visit. In contrast, women with five geriatric syndromes at baseline were 6.64 (95% CI: 4.15, 10.62) times as likely to develop disability by the three year follow-up as women with no geriatric syndromes. Adjustment for the Charlson score somewhat attenuated these associations (Table 4) but did not eliminate the trend (p<0.001). After adjustment for chronic diseases, compared to women with no geriatric syndromes, women with one syndrome were 1.14 (95% CI: 0.73, 1.76) times as likely and women with five geriatric syndromes were 4.67 (95% CI: 2.88, 7.56) times as likely to develop disability. Similarly, adjustment for pain attenuated but did not eliminate the association of geriatric syndromes with incident disability (Table 4; test for trend p<0.001). Models that adjusted for both Charlson score and pain were not substantially different from the models adjusting for each individually (data not shown).
Table 4.
Risk Ratios (RR) and 95% confidence intervals (CI) for total number or type of geriatric syndrome (GS) at baseline and 3-year incidence of ADL disability for women aged 65 years and older from the Women’s Health Initiative Observational Study (n=29544)
| RR Adjusted | 95% CI | RR Adjusted + Charlson | 95% CI | RR Adjusted+ Pain | 95% CI | |
|---|---|---|---|---|---|---|
| 0 GS | 1.0 | 1.0 | 1.0 | |||
| 1 GS | 1.21 | 0.78, 1.87 | 1.14 | 0.73, 1.76 | 1.05 | 0.68, 1.63 |
| 2 GS | 1.56 | 1.01, 2.41 | 1.32 | 0.85, 2.04 | 1.21 | 0.78, 1.87 |
| 3 GS | 3.41 | 2.25, 5.17 | 2.70 | 1.77, 4.13 | 2.41 | 1.57, 3.68 |
| 4 GS | 4.98 | 3.21, 7.73 | 3.76 | 2.40, 5.89 | 3.17 | 2.01, 4.98 |
| 5 GS | 6.64 | 4.15, 10.62 | 4.67 | 2.88, 7.56 | 3.63 | 2.22, 5.94 |
| Depressive symptoms | 2.41 | 1.82, 3.20 | 2.10 | 1.58, 2.79 | 1.75 | 1.32, 2.34 |
| Dizziness | 2.01 | 1.59, 2.56 | 1.73 | 1.35, 2.20 | 1.58 | 1.24, 2.02 |
| Falls | 2.03 | 1.54, 2.67 | 1.85 | 1.41, 2.44 | 1.71 | 1.30, 2.25 |
| Hearing Impairment | 1.46 | 1.04, 1.66 | 1.24 | 0.98, 1.57 | 1.20 | 0.95, 1.52 |
| Osteoporosis | 2.04 | 1.56, 2.67 | 1.69 | 1.29, 2.23 | 1.65 | 1.26, 2.16 |
| Polypharmacy | 2.45 | 1.96, 3.07 | 1.95 | 1.54, 2.46 | 1.88 | 1.12, 1.50 |
| Sleep Disturbance | 1.44 | 1.01, 2.07 | 1.27 | 0.88, 1.82 | 1.13 | 0.79, 1.62 |
| Syncope | 1.94 | 1.13, 3.33 | 1.77 | 1.04, 3.02 | 1.54 | 0.90, 2.63 |
| Urinary Incontinence | 1.44 | 1.15, 1.81 | 1.27 | 1.00, 1.60 | 1.20 | 0.95, 1.51 |
| Visual Impairment | 1.74 | 1.37, 2.21 | 1.60 | 1.26, 2.04 | 1.49 | 1.17, 1.89 |
Adjusted by age, income, smoking status
Each individual geriatric syndrome had a significant association with incident disability before adjustment for chronic diseases (Table 4). After adjustment for the Charlson score, hearing impairment and sleep disturbance were no longer significantly associated with incident disability. Adjustment for pain eliminated the association of hearing impairment, sleep disturbance, syncope, and urinary incontinence with incident disability (Table 4).
Additional analyses were conducted to assess the sensitivity of the results to inclusion of particular geriatric syndromes at baseline. Removal of each individual geriatric syndrome did not qualitatively change the results(data not shown).
The mean number of geriatric syndromes increased significantly from baseline (1.6) to follow-up (2.0; p ≤ 0.001). Only 33.8% of women had the same count of geriatric syndromes at follow-up as they did at baseline. However, the majority of women (75.8%) differed by no more than 1 geriatric syndrome from their baseline count. It was more common for women to acquire new geriatric syndromes (45.2%) rather than reduce their count (21.0%) (Table 5). Falls, dizziness, and visual impairment were the most likely geriatric syndromes to have abated and when combined accounted for half of the observed decrease in geriatric syndrome count. Results using follow-up measures of geriatric syndromes were not qualitatively different than those using baseline measures (Table 5). Adjustment for the Charlson score or pain at follow-up attenuated the results slightly as with adjustment at baseline (data not shown). It is not possible from the available data to determine whether the geriatric syndromes at follow-up preceded onset of disability.
Table 5.
Prevalence of geriatric syndromes (GS) at baseline (n=29544) and year 3 follow-up (n=22099) and associations (relative risk (RR) and 95% confidence interval (CI)) with activities of daily living at follow-up among women aged 65 years and older from the Women’s Health Initiative Observational Study
| Number of GS* | Baseline – N (%) | Follow-up – N (%) | Baseline RR** | Baseline 95% CI | Follow-up RR** | Follow-up 95% CI |
|---|---|---|---|---|---|---|
| 0 | 6768 (23.7) | 3426 (15.5) | Ref | -- | Ref | -- |
| 1 | 8582 (30.1) | 5675 (25.7) | 1.21 | 0.78, 1.87 | 1.04 | 0.51, 2.11 |
| 2 | 6635 (23.3) | 5497 (24.9) | 1.56 | 1.01, 2.41 | 1.87 | 0.98, 3.55 |
| 3 | 3716 (13.0) | 3741 (16.9) | 3.41 | 2.25, 5.17 | 2.71 | 1.42, 5.14 |
| 4 | 1780 (6.2) | 2182 (9.9) | 4.98 | 3.21, 7.73 | 3.28 | 1.68, 6.41 |
| 5+ | 1040 (3.7) | 1578 (7.1) | 6.64 | 4.15, 10.62 | 7.93 | 4.26, 14.79 |
includes total number of high depressive symptoms, dizziness, falls, hearing impairment, osteoporosis, polypharmacy, sleep disturbance, syncope, urinary incontinence, and visual impairment
adjusted for age, income and smoking status
DISCUSSION
A significant association between number of geriatric syndromes and incident disability was observed in this population of women aged 65 years and older. As the number of geriatric syndromes increased, the risk of developing disability in activities of daily living over a three-year period increased. Women who had five or more geriatric syndromes were more than six times as likely to have incident disability as women with no syndromes. This association persisted with adjustment for the Charlson score and pain, indicating that it is not dependent on presence of chronic disease or pain.
These findings are consistent with existing literature, most of which has focused on clinical populations or on single geriatric syndromes. Individual geriatric syndromes are known to be associated with functional impairment 7, 12, 24–29 and assessments in clinical samples have demonstrated strong associations between multiple geriatric syndromes and functional outcomes 30, 31. Two cross-sectional studies have shown an association between multiple geriatric syndromes and disability or functioning in the general population 4, 6. Cigolle and colleagues demonstrated a strong association between presence of geriatric syndromes and ADL dependency in a nationally representative sample of adults aged 65 years and older. This association was stronger for those with multiple syndromes and was independent of chronic diseases 4. A previous analysis of WHI data found a cross-sectional association of geriatric syndromes with physical and social functioning that was modified by the presence of cardiovascular disease or diabetes 6. An increasing number of chronic diseases has been shown to predict incident ADL disability 32 and in many studies, geriatric syndromes have been as good or better indicators of health outcomes as chronic diseases 4, 6, 30, 31.
This is the first study to assess number of geriatric syndromes and incident disability in a community-dwelling population providing evidence that geriatric syndromes precede and may contribute to onset of disability. Importantly, these results indicate that risk of disability is elevated for women with three or more geriatric syndromes suggesting that presence of multiple geriatric syndromes may be an important clinical indicator.
Although the results presented here suggest that geriatric syndromes contribute to disability in older women, their role in the disablement process is not yet clear. These syndromes may represent underlying pathology, system impairment, or presence of other risk factors 3. Comorbidity, frailty, prior disability 2, related disruption to multiple organ systems, degradation of compensatory systems 5, 7, and multi-system impairments 1 all may be part of the path through which geriatric syndromes impact disablement in the elderly. The multi-factorial nature of geriatric syndromes and frailty complicates our understanding of these pathways. In addition, the current evidence does not establish that geriatric syndromes lead directly to disability. Geriatric syndromes and disability could be separate end points of shared risk factors. Understanding mechanisms through which geriatric syndromes contribute to disablement has important clinical implications 12 and should be the basis for future research.
This study has some limitations. Incidence of ADL disability in the current sample was similar to but slightly lower than that reported in other community-based samples and may reflect a healthy volunteer effect 33–36. We did not have regular assessment of geriatric syndromes in this population. Given our interest in establishing the temporal sequence between geriatric syndromes and disability, we focused our primary analysis on the association between baseline geriatric syndromes and incidence of disability. However, many of these geriatric conditions are intermittent in nature and chronicity may be an important factor to consider 7. In this population, 42% of the women acquired new geriatric syndromes during the follow-up period. Analyses that considered the count of geriatric syndromes at year 3 in relation to new disability over the follow-up period were similar to the results of the analysis with baseline geriatric syndromes. Additional studies with more frequent follow-up of geriatric syndromes are needed to evaluate short-term and long-term patterns in geriatric syndromes and the relation between these patterns and incidence of disability in community-dwelling older adults.
There is currently no consensus on which conditions should be considered geriatric syndromes 4. Standardization of this definition would help advance research and clinical practice. Some of the conditions included in these analyses could arguably be considered chronic conditions, notably osteoporosis. In addition, polypharmacy may be a risk factor for geriatric syndromes, rather than a true geriatric syndrome itself 37. We included conditions that are frequently cited in lists of geriatric syndromes among community-dwelling older adults4, 5, 8 and for which there was biological justification. Older adults are at risk for high depressive symptoms as a result of neurologic and vascular changes to the brain and the response to adverse life events 38, 39. Dizziness is common in older adults and is typically not due to a single cause 7, 40. Sensory impairments are common in older adults and arise from anatomical changes to sensory organs and neuronal impairments 41, 42. Falls are a well-recognized geriatric syndrome that arise from disturbances in neurologic systems, musculature, and balance 7, 39. Osteoporosis arises from disturbance of hormonal and inflammatory controls of bone formation and resorbtion43. Polypharmacy may indicate over prescription or inappropriate combinations of medications resulting in adverse health outcomes and increased physical vulnerability 37, 44. Problems with sleep are generally multifactorial and can be caused from a combination of physiological declines and psychosocial influences 45. Syncope is often mediated by cardiologic and neurologic causes, though is often of unexplained origin 46. Finally, Urinary incontinence can arise from problems in the urinary tract itself or from vascular changes in the brain 7, 39. Our sensitivity analyses indicate that these results are not conditional on the inclusion of any particular condition.
There is also no standard concerning severity of conditions to be considered geriatric syndromes. In these analyses geriatric syndromes were considered present or absent without consideration of severity due to lack of consistent data on severity of conditions. Restricting inclusion to more severe forms might have reduced prevalence of these conditions and possibly changed the observed associations.
We may have excluded important conditions, most notably cognitive impairment, due to lack of data available for this sample of women. Prevalence of cognitive impairment at baseline for the Women’s Health Initiative Memory Study (a sub-study of the clinical trial portion of the WHI) was 5.8% 47. While we do not know how inclusion of cognitive impairment may have impacted these results, our sensitivity analysis indicates that exclusion of any one geriatric syndrome did not alter our findings; this may also be true for cognitive impairment. Given the strong association of cognitive impairment with disability 48, 49, we may be underestimating the association of geriatric syndromes with disability.
Finally, this study was limited by the restriction to women. Women have higher prevalence of geriatric syndromes but not ADL disability compared to men50. Evidence from studies of effect modification by sex for the association of chronic diseases with ADL disability have generally found that associations were the same for men and women 50. Future studies should include both genders and assess whether the association of number of geriatric syndromes with disability differs by sex.
To our knowledge, this was the first longitudinal study to assess the relation between number of geriatric syndromes and incident disability in community dwelling older adults. Our results demonstrate that presence of geriatric syndromes precedes dependency in ADL. Most previous papers focused on clinical or hospitalized patients. We demonstrate that multiple geriatric syndromes are an important health indicator among healthy community-dwelling older women. Future research should focus on understanding how geriatric syndromes contribute to the disablement process. Geriatric syndromes and their common risk factors may represent an important target for prevention of disability in older women.
Acknowledgments
This work was supported by the National Institute of Aging (R03AG031973) to YLM. The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201100046C, HHSN268201100001C, HHSN268201100002C, HHSN268201100003C, HHSN268201100004C, and HHSN271201100004C.
Sponsor’s Role: None
Appendix. SHORT LIST OF WHI INVESTIGATORS
Program Office: (National Heart, Lung, and Blood Institute, Bethesda, Maryland) Jacques Rossouw, Shari Ludlam, Dale Burwen, Joan McGowan, Leslie Ford, and Nancy Geller
Clinical Coordinating Center: Clinical Coordinating Center: (Fred Hutchinson Cancer Research Center, Seattle, WA) Garnet Anderson, Ross Prentice, Andrea LaCroix, and Charles Kooperberg
Investigators and Academic Centers: (Brigham and Women’s Hospital, Harvard Medical School, Boston, MA) JoAnn E. Manson; (MedStar Health Research Institute/Howard University, Washington, DC) Barbara V. Howard; (Stanford Prevention Research Center, Stanford, CA) Marcia L. Stefanick; (The Ohio State University, Columbus, OH) Rebecca Jackson; (University of Arizona, Tucson/Phoenix, AZ) Cynthia A. Thomson; (University at Buffalo, Buffalo, NY) Jean Wactawski-Wende; (University of Florida, Gainesville/Jacksonville, FL) Marian Limacher; (University of Iowa, Iowa City/Davenport, IA) Robert Wallace; (University of Pittsburgh, Pittsburgh, PA) Lewis Kuller; (Wake Forest University School of Medicine, Winston-Salem, NC) Sally Shumaker
Women’s Health Initiative Memory Study: (Wake Forest University School of Medicine, Winston-Salem, NC) Sally Shumaker
Footnotes
Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper.
Conflicts of interest: There are no conflicts of interest to report.
Author’s Contributions: All authors meet the criteria for authorship stated in the Uniform Requirements for Manuscripts Submitted to Biomedical Journals. All authors contributed to conception and design of the paper. Andrea Rosso conducted analyses. Andrea Rosso and Yvonne Michael drafted the paper. All authors contributed to critical revision of the paper and have approved publication.
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