Table 2.
Cumulative incidence and odds ratios (ORs) for cognitive declinea according to levels of predictor variables
| Predictors | Cumulative incidence | Unadjusted OR (95% CI) | Adjusted ORb (95% CI) | Fully-adjustedc OR (95% CI) |
|---|---|---|---|---|
| Age (years) | P for trend< 0.0001 | |||
| 65–69 | 12/97 (12.4%) | 1 (Ref) | ||
| 70–79 | 46/200 (23.0%) | 2.12 (1.06–4.21) | ||
| 80–89 | 45/87 (51.7%) | 7.59 (3.63–15.85) | ||
| 90–99 | 3/5 (60.0%) | 10.62 (1.61–70.22) | ||
| Sex | ||||
| Men | 46/159 (28.9%) | 1 (Ref) | 1 (Ref) | |
| Women | 60/230 (26.1%) | 0.87 (0.55–1.36) | 0.80 (0.49–1.29) | |
| Area of residence | ||||
| Heisei-cho | 30/103 (29.1%) | 1 (Ref) | 1 (Ref) | |
| Matto | 37/165 (22.4%) | 0.70 (0.40–1.23) | 0.70 (0.39–1.27) | |
| Katakai | 39/121 (32.2%) | 1.16 (0.65–2.05) | 1.14 (0.62–2.09) | |
| Family environment | ||||
| Living with family | 94/359 (26.2%) | 1 (Ref) | 1 (Ref) | |
| Living alone | 12/30 (40.0%) | 1.88 (0.87–4.05) | 1.81 (0.81–4.03) | |
| Job status | ||||
| Employed | 23/136 (16.9%) | 1 (Ref) | 1 (Ref) | |
| Unemployed/retired | 83/253 (32.8%) | 2.40 (1.43–4.03) | 1.78 (1.03–3.07) | |
| History of hypertension | ||||
| Absent | 44/198 (22.2%) | 1 (Ref) | 1 (Ref) | |
| Present | 62/191 (32.5%) | 1.68 (1.07–2.64) | 1.23 (0.76–1.99) | |
| History of cerebrovascular disease | ||||
| Absent | 101/374 (27.0%) | 1 (Ref) | 1 (Ref) | |
| Present | 5/15 (33.3%) | 1.35 (0.45–4.05) | 1.23 (0.40–3.80) | |
| History of diabetes | ||||
| Absent | 99/356 (27.8%) | 1 (Ref) | 1 (Ref) | |
| Present | 7/33 (21.2%) | 0.70 (0.29–1.66) | 0.72 (0.29–1.77) | |
| Alcohol consumptiond(gou/wk) | P for trend = 0.3590 | P for trend = 0.7898 | ||
| Non-drinker | 64/208 (30.8%) | 1 (Ref) | 1 (Ref) | |
| < 7 | 13/58 (22.4%) | 0.65 (0.33–1.29) | 0.71 (0.34–1.45) | |
| 7–13 | 11/58 (19.0%) | 0.53 (0.26–1.08) | 0.70 (0.33–1.48) | |
| 14–20 | 11/44 (25.0%) | 0.75 (0.36–1.58) | 0.95 (0.43–2.09) | |
| ≥ 21 | 7/21 (33.3%) | 1.13 (0.43–2.92) | 1.88 (0.68–5.18) | |
| Smoking | P for trend = 0.2706 | P for trend = 0.0563 | ||
| Non-smoker | 72/277 (26.0%) | 1 (Ref) | 1 (Ref) | |
| Past smoker | 17/62 (27.4%) | 1.08 (0.58–2.00) | 1.31 (0.67–2.56) | |
| Current smoker | 17/50 (34.0%) | 1.47 (0.77–2.79) | 1.94 (0.97–3.87) | |
| Bedtime | P for trend = 0.0698 | P for trend = 0.1472 | P for trend = 0.0480 | |
| -8:59 p.m. | 13/45 (28.9%) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 9:00–9:59 p.m. | 38/116 (32.8%) | 1.20 (0.57–2.54) | 1.28 (0.58–2.85) | 1.29 (0.55–3.04) |
| 10:00–10:59 p.m. | 33/118 (28.0%) | 0.96 (0.45–2.04) | 0.93 (0.42–2.09) | 0.80 (0.32–2.00) |
| 11:00 p.m.- | 22/110 (20.0%) | 0.62 (0.28–1.36) | 0.71 (0.30–1.65) | 0.50 (0.18–1.39) |
| Duration of nighttime sleep (hr) | P for trend = 0.0284 | P for trend = 0.2737 | P for trend = 0.7540 | |
| < 6 | 17/71 (23.9%) | 1.00 (0.50–1.97) | 1.16 (0.57–2.36) | 1.33 (0.61–2.88) |
| 6–6.9 | 24/103 (23.3%) | 0.96 (0.52–1.78) | 1.03 (0.54–1.94) | 1.13 (0.57–2.24) |
| 7–7.9 | 30/125 (24.0%) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 8–8.9 | 26/67 (38.8%) | 2.01 (1.06–3.81) | 1.67 (0.84–3.32) | 1.55 (0.74–3.26) |
| ≥ 9 | 9/23 (39.1%) | 2.04 (0.80–5.17) | 1.73 (0.63–4.76) | 1.47 (0.50–4.35) |
| Duration of daytime nap (min) | P for trend = 0.1085 | P for trend = 0.8387 | P for trend = 0.9923 | |
| None | 44/153 (28.8%) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 1–29 | 15/98 (15.3%) | 0.45 (0.23–0.86) | 0.46 (0.23–0.90) | 0.47 (0.23–0.96) |
| 30–59 | 21/74 (28.4%) | 0.98 (0.53–1.82) | 0.83 (0.43–1.59) | 0.79 (0.40–1.58) |
| ≥ 60 | 26/64 (40.6%) | 1.70 (0.92–3.12) | 1.11 (0.57–2.15) | 1.05 (0.51–2.13) |
| Sleep disturbance | ||||
| Absent | 91/338 (26.9%) | 1 (Ref) | 1 (Ref) | |
| Present | 14/50 (28.0%) | 1.06 (0.54–2.05) | 1.20 (0.60–2.41) | |
| Use of sleeping pills | ||||
| No | 81/308 (26.3%) | 1 (Ref) | 1 (Ref) | |
| Yes | 25/81 (30.9%) | 1.25 (0.73–2.14) | 1.13 (0.64–2.00) | |
aΔHDS-R ≤ 3
bAdjusted for age and baseline HDS-R score
cAdjusted for age, baseline HDS-R score, sex, region (dummy variables), family environment, job status, histories of hypertension, cerebrovascular diseases, and diabetes, alcohol consumption, smoking status, bedtime, duration of sleep, duration of nap (0, 1–29 min; 1, others), presence of sleep disturbance, and use of sleeping pills
dEquivalent to Japanese sake (1 gou of sake is equivalent to 180 ml sake or 27 g ethanol)