Table 1.
Characteristics of overall cohort and by number of impairments in sleep health dimensions
| Characteristics | Number of impairments in sleep health dimensions | |||||
|---|---|---|---|---|---|---|
| Overall cohort | 0 | 1 | 2 | 3–5 | ||
| (n = 1,459) | (n = 310) | (n = 456) | (n = 355) | (n = 338) | P-value | |
| Age, years, mean (SD) | 83.6 (3.90) | 83.5 (3.92) | 83.9 (4.11) | 83.7 (3.75) | 83.3 (3.76) | 0.17 |
| African American, n (%) | 173 (11.9) | 20 (6.5) | 51 (11.2) | 46 (13.0) | 56 (16.6) | <0.001 |
| Lives alone, n (%) | 875 (60.0) | 181 (58.4) | 279 (61.2) | 214 (60.3) | 201 (59.5) | 0.88 |
| Ever smoker, n (%) | 543 (41.8) | 135 (46.4) | 157 (38.3) | 134 (43.1) | 117 (40.9) | 0.18 |
| Alcoholic drinks/week past 30 days, mean (SD) | 1.3 (3.22) | 1.7 (3.46) | 1.3 (3.13) | 1.1 (3.15) | 1.2 (3.17) | 0.08 |
| Caffeine intake, mg/d, mean (SD) | 137 (144) | 144 (145) | 136 (143) | 135 (147) | 132 (140) | 0.78 |
| No. of IADL impairment, n (%) | <0.001 | |||||
| None | 726 (49.8) | 190 (61.3) | 226 (49.6) | 172 (48.5) | 138 (40.8) | |
| 1 | 241 (16.5) | 42 (13.5) | 80 (17.5) | 62 (17.5) | 57 (16.9) | |
| 2 | 176 (12.1) | 34 (11.0) | 50 (11.0) | 41 (11.5) | 51 (15.1) | |
| 3 | 135 (9.3) | 20 (6.5) | 48 (10.5) | 26 (7.3) | 41 (12.1) | |
| ≥4 | 181 (12.4) | 24 (7.7) | 52 (11.4) | 54 (15.2) | 51 (15.1) | |
| No. of ADL impairment, n (%) | <0.001 | |||||
| None | 1225 (84.0) | 279 (90.0) | 391 (85.7) | 289 (81.4) | 266 (78.7) | |
| 1 or more | 234 (16.0) | 31 (10.0) | 65 (14.3) | 66 (18.6) | 72 (21.3) | |
| Geriatric Depression Scale score, n (%) | <0.001 | |||||
| 0–1 | 678 (46.5) | 187 (60.3) | 235 (51.5) | 148 (41.7) | 108 (32.0) | |
| 2–5 | 602 (41.3) | 107 (34.5) | 173 (37.9) | 157 (44.2) | 165 (48.8) | |
| ≥6 | 179 (12.3) | 16 (5.2) | 48 (10.5) | 50 (14.1) | 65 (19.2) | |
| Medical conditions* (0–14), n (%) | <0.001 | |||||
| None | 127 (8.7) | 37 (11.9) | 48 (10.5) | 28 (7.9) | 14 (4.1) | |
| 1 | 332 (22.8) | 88 (28.4) | 105 (23.0) | 78 (22.0) | 61 (18.0) | |
| 2 | 353 (24.2) | 78 (25.2) | 117 (25.7) | 88 (24.8) | 70 (20.7) | |
| 3 | 325 (22.3) | 61 (19.7) | 100 (21.9) | 75 (21.1) | 89 (26.3) | |
| ≥4 | 322 (22.1) | 46 (14.8) | 86 (18.9) | 86 (24.2) | 104 (30.8) | |
| MMSE score, mean (SD) | 27.6 (2.04) | 27.6 (2.14) | 27.5 (2.00) | 27.5 (2.07) | 27.7 (1.95) | 0.35 |
| Hospitalization in past year, n (%) | 354 (24.3) | 67 (21.6) | 112 (24.6) | 78 (22.0) | 97 (28.7) | 0.12 |
| Incident hospitalization, n (%) | 851 (58.3) | 164 (52.9) | 259 (56.8) | 221 (62.3) | 207 (61.2) | 0.05 |
| Incident SNF stay, n (%) | 355 (24.3) | 76 (24.5) | 100 (21.9) | 88 (24.8) | 91 (26.9) | 0.44 |
| Total annual health-care costs, US $ | ||||||
| Median (IQR) | $6,318 | $4,987 | $6,387 | $6,811 | $7,267 | |
| (2,297–16,086) | (1,751–13,423) | (2,411–15,703) | (2,564–16,470) | (2,473–17,572) | ||
| Mean (SD) | $12,588 (18,057) | $10,745 (15,795) | $11,773 (16,151) | $12,632 (16,837) | $15,332 (22,810) | 0.007 |
| Annual outpatient costs, US $ | ||||||
| Median (IQR) | $2,680 | $2,523 | $2,710 | $2,813 | $2,868 | |
| (1,506–4,733) | (1,281–4,065) | (1,553–4,634) | (1,448–4,925) | (1,661–5,009) | ||
| Mean (SD) | $3,808 (4,236) | $3,553 (4,364) | $3,961 (4,892) | $3,725 (3,402) | $3,925 (3,948) | 0.55 |
| Died during follow-up, n (%) | 196 (13.4) | 28 (9.0) | 58 (12.7) | 58 (16.3) | 52 (15.4) | 0.03 |
IQR, interquartile range; MMSE, Mini-Mental State Examination.
*Medical conditions include hypertension, congestive heart failure, myocardial infarction, angina, stroke, diabetes, chronic lung disease, cancer, osteoarthritis, rheumatoid arthritis, depression, Alzheimer’s disease, parkinsonism, and osteoporosis.