Of the 3010 elders age ≥ 75 who had scheduled primary care visits during the ACOVE-2 study, 2671 (88.7%) were screened for the three geriatric syndromes, 57 (1.9%) could not be screened due to language barrier, 50 (1.7%) had no available proxy, 78 (2.6%) refused to participate, and 154 (5.1%) could not be reached by telephone. Of those who were screened, 784 (29.3%) screened positively for one or more of the geriatric conditions (602 [22.5%] for fear of fall/falls, 279 [10.4%] for urinary incontinence, and 104 [3.9%] for memory impairment/dementia). Those who screened positively for one or more conditions were older (mean 82 versus 81, p<.001), less often male (32.8% versus 45.3%, p<.001), and more likely to participate by proxy respondent (19.2% versus 4.7%, p<.001) than those who screened negative for all three conditions. Of those who screened positively, 649 (82.8%) consented to participate in the study. Those who consented did not differ significantly (p<.05) from those who declined with respect to age, gender, or need for proxy respondent.
There were 501 who screened positively for falls, 233 who screened positively for UI, and 78 who screened positively for dementia. Individuals could screen positive for more than one condition: 115 screened positively for both falls and UI, 44 for both falls and dementia, 16 for both UI and dementia, and 11 for all three conditions. At baseline the mean age was 81 for the original ACOVE-2 sample as well as for the falls and incontinence subsamples. The dementia subsample was slightly older at mean 84 years (p=.10 compared to falls subsample). The overall sample was 37.2% male, with fewer males in the incontinence sample (24.9% versus 40.0% for the falls subsample, p<.001). A proxy respondent was used for 19.9% of participants, with fewer proxies in the UI group (13.6%, p= .03) and exclusively proxy respondents for the dementia group (p<.001). The baseline count of daily activity abilities (Short Functional Survey Score, range 0–5) averaged 4.0 for the overall sample, but the UI group was slightly more independent (4.2 abilities, p=.008) and the dementia group was less independent (2.6 abilities, p=.005) than the falls subsample (3.9 abilities). While the overall sample baseline VES-13 score averaged 4.7, the incontinence subsample had a slightly lower average (4.3, p=<.001), whereas the dementia subsample had a higher mean (6.9, p=.004) compared to the falls subsample (4.9) ().
Among the full ACOVE-2 sample (n=649), 222 (34..2% died during the study period, with date of death ranging from 7 days to 5.8 years after study enrollment. Perfect matches (exact date of birth, same full name, and same city of death) were found for 195 (87.8%), a different city of death (but exact birth date and name) was listed for 21 (9.5%), initials for first name were found on Social Security records instead of full first name (but same date of birth and city of death was same as city of residence) for 3 individuals (1.4%), and date of birth differed by one digit (but same full name and city of residence) for 6 (2.7%).
We interviewed 295 of the surviving cohort (69.1%) to obtain their follow-up functional status. Those who survived but were lost to follow-up interview (n = 141) did not differ significantly on the basis of mean age (age 81 for both groups, p=.78) or low income (28.4% versus 26.0%, p=.6) compared to those for whom who we had follow-up information (interview or mortality data, n=508). However, those lost to follow up were more likely to be female (37.2% versus 22.0%, p=.007) and have a lower baseline VES-13 score (mean 4.2 versus 4.7, p=.04) compared to our analytic sample. Mean time to interview was 4.5 years (3.8–5.3 years, standard deviation = .35 years).
Of those interviewed (n=295), 116 (39.3%) experienced functional decline. Seven participants who underwent functional decline also died after their interview but within the study period (range = 38 to 214 days after their interviews). We classified these individuals as deaths for the trichotomous (no decline versus decline versus death) outcome. Therefore, among our analytic sample (n=508), 177 (34.8%) survived and did not decline, 109 underwent functional decline (21.5%), and 222 (43.7%) died.
The mean baseline VES-13 score for the trichotomous outcome categories were 3.1 for those who did not decline, 4.8 for those who declined, and 6.0 for those who died (p<.0001). The mean baseline VES-13 score was 5.6 for those who declined or died (vs. 3.1 for those who did not, p<.0001).
The VES-13 score (multinomial logistic regression unadjusted for covariates but weighted for non-response and adjusted for clustering) was associated with greater odds of death versus no decline (OR 1.45 per point, 95% CI 1.33–1.58) and decline versus no decline (OR 1.28. 95% CI 1.14–1.42) (). An elder with a baseline VES-13 score of 1 (age ≥ 75 only) had a predicted probability of death of 5% and a 66% chance of surviving without functional decline or death over the 5-year follow up period. In contrast, an elder with a baseline VES-13 score of 10 had a 64% predicted risk of dying and a 10% chance of surviving without functional decline over the 5-year follow up period ().
Association between Vulnerable Elders-13 Survey and 5-year Functional Status and Survival Outcomes
Using clustered logistic regression, with sample weighting for non-response, each 1 point increase in baseline VES-13 was associated with a 1.37 times higher odds of death or decline (95% CI 1.25–1.50; ). The area under the receiver operating characteristic curve was 0.75 (95% CI .71–.80) (). The sensitivities and specificities for cutoff values from 2 to 10 for this sample of patients age 75 and older who screened positive for a geriatric condition appear in . A cutoff VES-13 score of 5 results in a sensitivity and specificity of .69. Other cut-points can be selected based on desired sensitivity or specificity.
Unadjusted Sensitivity and Specificities for Predicting Poor Health Outcomes At Different Cutoff Values of the Vulnerable Elders-13 Score
Adding length of follow-up time or an indicator of intervention status as a predictor in the regression models did not result in substantial changes in the odds ratios associated with VES-13 scores.
The mean number of years until death among decedents was 2.9 (range 0.02 to 5.8). The sample was divided into better versus poorer prognosis (VES-13 score of ≤ 4 versus ≥ 5). Kaplan-Meier curves appear in . The Cox proportional hazard ratio associated with each additional VES-13 point was 1.23 (95% CI 1.19–1.27).
Figure 2 Poorer (higher) VES-13 scores are associated with greater risk of dying throughout the 4.5 year follow up period for the overall whole sample, the falls subset, and the urinary incontinence subset. The dementia subset experienced similar mortality rates (more ...)
The direction of the effect of the VES-13 scores on trichotomous and dichotomous outcomes was similar within the three condition subgroups (). Each additional point on the VES-13 appears to have had a greater effect on poor outcomes for the dementia subgroup, but the confidence intervals were wider due to smaller subsample. Upon examination of graphical representation of the multinomial logistic regressions and survival analyses by subsample ( and ), VES score consistently predicted increasingly poor outcomes in all subsamples. The difference in effect of the VES-13 by screened conditions was not significant in a pooled sample (p=.37, .27, .29 for joint test of interaction terms in the models using trichotomous, dichotomous, and death-only outcomes, respectively).