Table 2.
Comparison of Participant Characteristics During Periods when Living Alone Versus Living with Others: All Periods (2a) and Periods During Which Participants Were Aged 85+ (2b)*
| 2a | All Follow-Up Periods | ||||
| Living Alone (n = 4,100) | Living with Others (n = 6,331) | Unadjusted p value | Age & Sex Adjusted p value† | All Periods (N = 10,431) | |
| All-Cause Admission, n (%) | 1,062 (25.9) | 1,607 (25.4) | 0.55 | 0.12 | 2,669 (25.6) |
| ACSC Admission, n (%) | 242 (5.9) | 393 (6.2) | 0.52 | 0.05 | 635 (6.1) |
| Age‡, n (%) | |||||
| 65–74 | 1,019 (24.9) | 2,295 (36.3) | < 0.01 | – | 3,314 (31.8) |
| 75–84 | 2,129 (51.9) | 3,250 (51.3) | – | 5,379 (51.6) | |
| 85+ | 952 (23.2) | 786 (12.4) | – | 1,738 (16.6) | |
| Female, n (%) | 3,211 (78.3) | 3,000 (47.4) | < 0.01 | < 0.01 | 6,211 (59.5) |
| Nonwhite, n (%) | 287 (7.0) | 537 (8.5) | 0.01 | 0.32 | 824 (7.9) |
| Married, living as‡, n (%) | 147 (3.7) | 4,925 (80.6) | < 0.01 | < 0.01 | 5,072 (50.3) |
| Income < $15,000‡, n (%) | 927 (22.6) | 457 (7.2) | < 0.01 | < 0.01 | 1,384 (13.3) |
| High School Graduate, n (%) | 3,356 (81.9) | 5,073 (80.2) | 0.09 | 0.20 | 8,429 (80.9) |
| Difficulty with 1+ ADL#, n (%) | 1,302 (31.8) | 1,756 (27.7) | < 0.01 | 0.06 | 3,058 (29.3) |
| PPF Score‡§, mean (SD) | 9.5 (2.9) | 9.7 (3.0) | < 0.01 | 0.04 | 9.6 (2.9) |
| Poor self-reported health#, n (%) | 102 (2.5) | 190 (3.0) | 0.12 | 0.08 | 292 (2.8) |
| Depression‡||, n (%) | 475 (11.8) | 574 (9.2) | < 0.01 | 0.12 | 1,049 (10.3) |
| Diabetes‡ (ever reported), n (%) | 406 (10.0) | 774 (12.3) | < 0.01 | 0.08 | 1,180 (11.4) |
| Cancer‡ (ever reported), n (%) | 921 (22.6) | 1,509 (24.1) | 0.08 | 0.03 | 2,430 (23.5) |
| Heart Disease¶, n (%) | 961 (23.6) | 1,601 (25.6) | 0.03 | 0.71 | 2,562 (24.8) |
| Smoking Status‡, n (%) | |||||
| Never | 1,990 (48.8) | 2,963 (47.2) | < 0.01 | < 0.01 | 4,953 (47.8) |
| Past | 1,870 (45.9) | 3,072 (49.0) | 4,942 (47.7) | ||
| Current | 217 (5.3) | 241 (3.8) | 458 (4.4) | ||
| Dementia‡, n (%) | 118 (2.9) | 264 (4.2) | < 0.01 | < 0.01 | 382 (3.7) |
| Social Support‡#, mean (SD) | 8.1 (2.7) | 7.8 (2.4) | < 0.01 | < 0.01 | 7.9 (2.5) |
| RxRisk Score**, USD, mean (SD) | 4,111.0 (2,365.5) | 4,283.5 (2,834.6) | < 0.01 | 0.34 | 4,232.4 (2,685.1) |
| 2b | Follow-Up Periods during which Participants were Aged 85+ | ||||
| Living Alone (n = 952) | Living with Others (n = 786) | Unadjusted p-value | Age & Sex Adjusted p-value | All Periods (n = 1,738) | |
| All-Cause Admission, n (%) | 340 (35.7) | 334 (42.5) | < 0.01 | < 0.01 | 674 (38.8) |
| ACSC Admission, n (%) | 112 (11.8) | 114 (14.5) | 0.09 | 0.12 | 226 (13.0) |
| Age, n (%) | |||||
| 65–74 | – | – | – | – | – |
| 75–84 | – | – | – | – | – |
| 85+ | – | – | – | – | 100.0 |
| Female, n (%) | 773 (81.2) | 391 (49.8) | < 0.01 | < 0.01 | 1,164 (67.0) |
| Nonwhite, n (%) | 36 (3.8) | 46 (5.9) | 0.04 | 0.39 | 82 (4.7) |
| Married, living as, n (%) | 32 (3.5) | 436 (59.1) | < 0.01 | < 0.01 | 468 (28.5) |
| Income < $15,000, n (%) | 233 (24.5) | 87 (11.1) | < 0.01 | < 0.01 | 320 (18.4) |
| High School Graduate, n (%) | 709 (74.5) | 594 (75.6) | 0.13 | 0.50 | 1,303 (75.0) |
| Difficulty with 1+ ADL, n (%) | 444 (46.6) | 390 (49.6) | 0.22 | < 0.01 | 834 (48.0) |
| PPF Score, mean (SD) | 8.8 (3.3) | 8.2 (3.9) | < 0.01 | < 0.01 | 8.5 (3.6) |
| Poor self-reported health, n (%) | 41 (4.4) | 31 (4.1) | 0.75 | 0.94 | 72 (4.2) |
| Depression, n (%) | 110 (12.0) | 99 (13.6) | 0.35 | 0.22 | 209 (12.7) |
| Diabetes (ever reported), n (%) | 89 (9.5) | 61 (8.0) | 0.30 | 0.56 | 150 (8.8) |
| Cancer (ever reported), n (%) | 248 (26.3) | 227 (30.0) | 0.08 | 0.43 | 475 (28.0) |
| Heart Disease, n (%) | 274 (29.2) | 276 (36.5) | < 0.01 | 0.09 | 550 (32.5) |
| Smoking Status, n (%) | |||||
| Never | 544 (57.8) | 416 (54.8) | 0.04 | 0.06 | 960 (56.5) |
| Past | 375 (39.9) | 327 (43.1) | 702 (41.3) | ||
| Current | 22 (2.3) | 16 (2.1) | 38 (2.2) | ||
| Dementia, n (%) | 61 (6.4) | 115 (14.6) | < 0.01 | < 0.01 | 176 (10.2) |
| Social Support, mean (SD) | 8.1 (2.6) | 7.8 (2.5) | 0.02 | < 0.01 | 7.9 (2.6) |
| RxRisk Score, USD, mean (SD) | 4,639.9 (2,110.0) | 5,201.4 (2,697.5) | < 0.01 | 0.16 | 4,893.5 (2,408.8) |
*Follow-up periods rather than participants are the unit of analysis in this table. Thus, all categorical variables are reported as the percentage (%) of periods when each characteristic was present and continuous variables are averaged across follow-up periods. For example, 25.9 % of periods when subjects were living alone included an all-cause admission. The mean PPF score averaged across all follow-up periods was 9.6 (SD 2.9)
† P value tests if the percentages or means in periods when a participant was living alone versus not living alone differ, calculated using a logistic regression with period as the unit of analysis, controlling for age and sex, and accounting for repeated observations using GEE with empirical standard errors. Tests in age groups compare age 75+ years versus age < 75 and in smoking status compare ever versus never smoked. Values in bold are statistically significant at the p = 0.05 level
‡Time-varying variables were measured during biennial follow-up visits, and the updated values for each follow-up period were used in analysis
§PPF Score is the Performance-Based Physical Function Score ranging from 0 to 16. A higher PPF Score indicates better physical function
||Depression is flagged as present for a score of ≥ 10 on the Center for Epidemiologic Studies Depression Scale (CES-D)
¶Heart disease is defined as prevalent myocardial infarction, angina, coronary artery bypass grafting, and/or angioplasty
#Social support is measured by the mean score on the 6-item Interpersonal Support Evaluation List (ISEL), where each item is scored on a scale of 1–4 for a total potential score of 24. A lower score indicates higher levels of interpersonal support
**The RxRisk Score is measured in U.S. dollars. A lower RxRisk Score indicates a lower comorbidity burden