Abstract
This study uses data from the National Health and Aging Trends Study to determine the association of cognitive impairment and dementia with receipt of cataract surgery among community-dwelling Medicare beneficiaries.
Correcting visual impairment may optimize functioning and reduce the risk of further cognitive decline for people with cognitive impairment and dementia (CID).1,2 Cataracts cause visual impairment in more than 20% of older adults and are effectively treated with low-risk surgery.3 Clinical guidelines state that older adults with CID, except those with limited life expectancy or advanced dementia, should be offered effective treatments, including cataract surgery.4 It is not known whether older adults with CID in the United States receive cataract surgery at the same rate as those with normal cognition. We tested the hypothesis that community-dwelling Medicare beneficiaries with CID are less likely to receive cataract surgery than those with normal cognition.
Methods
Data and Analysis Sample
We used data from the National Health and Aging Trends Study (NHATS), a longitudinal survey annually administered to a nationally representative cohort of US Medicare beneficiaries 65 years and older (January 2011 to December 2016). We excluded participants who reported cataract surgery before enrollment. We censored participants after they reported receiving cataract surgery. In an effort to exclude those with advanced dementia, we excluded participants who required a proxy respondent or resided in nursing homes. The University of Michigan Institutional Review Board approved this study, and informed consent was waived because deidentified, publicly available survey data were used.
Variable Definitions
The outcome was self-reported receipt of cataract surgery measured annually. The predictor was CID using the NHATS system, which classifies participants as having probable CID (ie, report of physician diagnosis of dementia or Alzheimer disease or scores 1.5 SDs below the mean or lower on 2 or more cognitive tests of memory, orientation, and executive function), possible CID (a score 1.5 SDs below the mean or lower on 1 cognitive test), or no CID.5
Analyses
Based on the NHATS survey design, we calculated the weighted proportions of participants for each sociodemographic group stratified by classification of CID. We performed multivariable logistic regression to examine the effect of an individual’s CID classification on receipt of cataract surgery in the subsequent year while adjusting for patient-related factors, including age, sex, race/ethnicity, education, annual income, survey year, self-reported distance and near visual impairment, smoking status, depressive symptoms, social isolation, self-care and activity limitations, and comorbidity (ie, self-reported diagnosis of heart disease, hypertension, diabetes, lung disease, stroke, and cancer). We calculated adjusted predicted proportions of the outcome. All analyses accounted for the complex design of NHATS, including sampling weights, units, and strata, and were conducted using Stata version 14 (StataCorp).
Results
Table 1 presents participant characteristics. Participants with possible and probable CID were significantly less likely to receive cataract surgery than those with normal cognition after adjustment for patient factors (possible CID: adjusted odds ratio, 0.73; 95% CI, 0.56-0.95; P = .02; probable CID: adjusted odds ratio, 0.59; 95% CI, 0.36-0.96; P = .03). The adjusted predicted proportion receiving cataract surgery was 8.1% for those with normal cognition, 6.2% for those with possible CID, and 5.1% for those with probable CID (Table 2).
Table 1. Characteristics of Study Sample by Cognitive Impairment and Dementia (CID) Status, National Health and Aging Trends Study 2011-2016.
| Characteristic | No (%)a | P Valuec | ||
|---|---|---|---|---|
| Normal Cognitionb | Possible CIDb | Probable CIDb | ||
| Total | 10 271 (88.1) | 1213 (7.1) | 808 (4.7) | |
| Age, y | <.001 | |||
| 65-69 | 2508 (32.8) | 142 (17.8) | 49 (9.3) | |
| 70-74 | 3472 (37.2) | 254 (26.1) | 126 (23.6) | |
| 75-79 | 2227 (18.1) | 274 (23.9) | 146 (20.1) | |
| 80-84 | 1332 (8.1) | 258 (16.3) | 219 (23.2) | |
| 85-89 | 552 (3.0) | 169 (9.9) | 151 (14.9) | |
| ≥90 | 180 (0.7) | 116 (5.9) | 117 (8.9) | |
| Female sex | 5442 (51.8) | 613 (49.4) | 437 (53.2) | .57 |
| Race/ethnicity | <.001 | |||
| White | 7151 (81.4) | 596 (64.5) | 409 (67.2) | |
| Black | 2273 (8.2) | 477 (18.2) | 253 (12.1) | |
| Hispanic | 510 (5.9) | 86 (10.5) | 93 (13.8) | |
| Other | 337 (4.5) | 54 (6.7) | 53 (6.8) | |
| Education | <.001 | |||
| <High school degree | 1764 (13.8) | 475 (32.5) | 385 (43.9) | |
| High school degree | 2636 (25.1) | 297 (27.9) | 188 (27.4) | |
| >High school degree | 5767 (61.1) | 431 (39.6) | 205 (28.7) | |
| Income, $d | <.001 | |||
| 0-9999 | 875 (6.7) | 233 (15.9) | 173 (18.9) | |
| 10 000-24 999 | 2575 (20.9) | 479 (36.3) | 350 (39.3) | |
| 25 000-49 999 | 2807 (26.6) | 287 (24.4) | 181 (25.3) | |
| 50 000-99 999 | 2621 (29.1) | 149 (15.1) | 82 (12.4) | |
| >100 000 | 1392 (16.7) | 65 (8.3) | 21 (4.1) | |
| Visual impairment | ||||
| Distance | 317 (2.7) | 68 (4.8) | 71 (9.1) | <.001 |
| Near | 211 (1.5) | 80 (5.1) | 74 (8.8) | <.001 |
| Smoking status | .44 | |||
| Never smoker | 4974 (48.3) | 582 (47.4) | 442 (52.6) | |
| Past smoker | 4434 (43.4) | 506 (42.4) | 310 (39.8) | |
| Current smoker | 863 (8.3) | 125 (10.1) | 54 (7.6) | |
| Depressive symptomse | <.001 | |||
| Score of 0-2 | 9280 (91.8) | 998 (84.4) | 614 (76.2) | |
| Score of 3-6 | 943 (8.2) | 188 (15.6) | 176 (23.8) | |
| Social isolationf | <.001 | |||
| Not isolated | 2506 (26.8) | 119 (10.8) | 56 (9.5) | |
| Somewhat isolated | 6002 (57.8) | 664 (56.2) | 418 (51.3) | |
| Socially isolated | 1763 (15.4) | 430 (33.0) | 334 (39.2) | |
| Activity limitationsg | <.001 | |||
| No limitations | 8828 (88.1) | 808 (70.5) | 344 (44.1) | |
| 1-2 Limitations | 927 (7.9) | 187 (13.4) | 180 (23.2) | |
| 3-5 Limitations | 365 (2.8) | 143 (10.3) | 154 (17.7) | |
| 6-11 Limitations | 151 (1.2) | 75 (5.7) | 130 (15.1) | |
| Heart diseaseh | 1710 (15.8) | 219 (17.2) | 163 (21.9) | .06 |
| Hypertensionh | 6812 (37.3) | 829 (36.7) | 535 (34.3) | .59 |
| Diabetesh | 2488 (23.0) | 325 (25.9) | 256 (34.1) | <.001 |
| Lung diseaseh | 1625 (15.7) | 164 (15.1) | 153 (21.1) | .09 |
| Strokeh | 365 (3.1) | 87 (6.4) | 77 (8.5) | <.001 |
| Cancerh | 1294 (12.4) | 145 (12.8) | 86 (10.7) | .49 |
Data are presented as unweighted numbers and weighted percentages of US population of Medicare beneficiaries 65 years and older, accounting for the study design of the National Health and Aging Trends Study.
Study participants in each round were classified as having no dementia, possible dementia, or probable dementia based on having received a diagnosis of dementia from a physician and scores on cognitive testing according to a previously published classification method.5
P values are unadjusted and calculated using design-adjusted Pearson χ2 test.
Multiple imputation was used for missing income data.
Self-reported depressive symptoms on the Patient Health Questionnaire-2.
Social isolation determined using a method that takes into account spouse/partner status, communication with family/friends, and participation in social activities.
Count of self-care and activity limitations.
Self-report of having received 1 of these diagnoses from a physician.
Table 2. Association of Cognitive Impairment and Dementia (CID) Status on Receipt of Cataract Surgery, National Health and Aging Trends Study 2011-2016.
| CID Status | Adjusted Odds Ratio (95% CI)a | P Value | Adjusted Predicted Proportion, % (95% CI)a |
|---|---|---|---|
| No CID | 1 [Reference] | NA | 8.1 (7.4-8.8) |
| Possible CID | 0.73 (0.56-0.95) | .02 | 6.2 (4.8-7.5) |
| Probable CID | 0.59 (0.36-0.96) | .03 | 5.1 (3.0-7.2) |
Abbreviation: NA, not applicable.
Logistic regression model adjusted for age, sex, race/ethnicity, education, annual income, survey round, self-reported distance and near visual impairment, smoking status, depressive symptoms (score ≥3 on the Patient Health Questionnaire-2), social isolation, self-care and activity limitations, and self-reported diagnosis of heart disease, hypertension, diabetes, lung disease, stroke, and cancer.
Discussion
In this large, nationally representative study, community-dwelling Medicare beneficiaries with CID were less likely to receive cataract surgery than those with normal cognition. It is possible that CID is a proxy for other correlated factors (eg, older age, nonwhite race, lower educational attainment, lower income, depression, activity of daily living deficits, and history of stroke), which are also barriers to cataract extraction. Although we adjusted for many of these potential confounders, residual confounding could be present. Our study relies on self-reported data. Older adults are able to accurately report receipt of cataract surgery,6 although the accuracy of self-reported cataract surgery in those with CID is unreported.
Conclusions
We found that Medicare beneficiaries with CID were less likely to receive cataract surgery than those with normal cognition. Given that cataract surgery may help optimize functioning in persons with and without CID, it is important for primary care physicians, geriatricians, and ophthalmologists to be aware of the potential underuse of this effective, low-risk treatment in patients with CID.
References
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