Table 3.
Odds ratios (ORs) for cognitive impairment (HDS-R ≤20) according to the levels of predictor variables
| Predictor variables | Prevalence of cognitive impairment | Adjusted ORa (95 % CI) | P or P for trend |
|---|---|---|---|
| Sex | P = 0.0628 | ||
| Men | 16/243 (6.6 %) | 2.25 (0.96–5.27) | |
| Women | 10/294 (3.4 %) | 1 (Ref.) | |
| Age (years) | P for trend <0.0001 | ||
| 65–69 | 1/121 (0.8 %) | 1 (Ref.) | |
| 70–79 | 5/250 (2.0 %) | 2.46 (0.28–21.25) | |
| 80–89 | 12/147 (8.2 %) | 10.70 (1.37–83.78) | |
| 90–99 | 8/19 (42.1 %) | 87.77 (10.01–769.42) | |
| Family environment | P = 0.3143 | ||
| Living with family | 25/498 (5.0 %) | 1 (Ref.) | |
| Living alone | 1/39 (2.6 %) | 0.33 (0.04–2.83) | |
| Area of residence | P = 0.0046 | ||
| Urban area (Heisei-cho and Katakai) | 6/298 (2.0 %) | 1 (Ref.) | |
| Rural area (Matto) | 20/239 (8.4 %) | 4.04 (1.54–10.62) | |
| Current job status | P = 0.4421 | ||
| Unemployed | 22/361 (6.1 %) | 1 (Ref.) | |
| Employed | 4/174 (2.3 %) | 0.63 (0.19–2.07) | |
| History of hypertension | P = 0.2657 | ||
| Absent | 14/265 (5.3 %) | 1 (Ref.) | |
| Present | 12/272 (4.4 %) | 0.62 (0.27–1.44) | |
| History of cerebrovascular diseases | P = 0.4350 | ||
| Absent | 24/506 (4.7 %) | 1 (Ref.) | |
| Present | 2/31 (6.5 %) | 1.86 (0.39–8.75) | |
| History of diabetes | P = 0.4501 | ||
| Absent | 23/484 (4.8 %) | 1 (Ref.) | |
| Present | 3/53 (5.7 %) | 1.66 (0.45–6.16) | |
| Family history of dementia | P = 0.5046 | ||
| Absent | 24/466 (5.2 %) | 1 (Ref.) | |
| Present | 2/71 (2.8 %) | 0.60 (0.13–2.70) | |
| Alcohol consumptionb (gou/week) | P for trend = 0.7363 | ||
| Non-drinkers | 15/263 (5.7 %) | 1 (Ref.) | |
| <7 | 5/160 (3.1 %) | 0.49 (0.14–1.71) | |
| 7–13 | 3/76 (3.9 %) | 0.72 (0.14–3.77) | |
| ≥14 | 3/35 (8.6 %) | 2.59 (0.44–15.30) | |
| Smoking (Brinkman index) | P for trend = 0.5668 | ||
| Never-smoker | 15/360 (4.2 %) | 1 (Ref.) | |
| <675 | 9/105 (8.6 %) | 1.48 (0.48–4.58) | |
| ≥675 | 2/72 (2.8 %) | 0.45 (0.08–2.49) | |
| Bedtime | P for trend = 0.0392 | ||
| –8:59 p.m. | 12/87 (13.8 %) | 4.80 (0.93–24.68) | |
| 9:00–9:59 p.m. | 7/161 (4.3 %) | 1.49 (0.26–8.61) | |
| 10:00–10:59 p.m. | 5/158 (3.2 %) | 1.44 (0.26-8.11) | |
| 11:00 p.m.– | 2/131 (1.5 %) | 1 (Ref.) | |
| Hours of sleep | P for trend = 0.1028 | ||
| <6 | 2/91 (2.2 %) | 1 (Ref.) | |
| 6–6.9 | 4/130 (3.1 %) | 1.63 (0.27–9.82) | |
| 7–7.9 | 4/167 (2.4 %) | 1.06 (0.18–6.22) | |
| 8–8.9 | 8/105 (7.6 %) | 2.48 (0.49–12.69) | |
| ≥9 | 8/44 (18.2 %) | 5.14 (0.88–30.01) | |
| Having roles in family or community | P = 0.1534 | ||
| Yes | 20/505 (4.0 %) | 1 (Ref.) | |
| No | 6/32 (18.8 %) | 2.32 (0.73–7.35) | |
| Having activities for pleasure | P = 0.3380 | ||
| Yes | 24/513 (4.7 %) | 1 (Ref.) | |
| No | 2/24 (8.3 %) | 2.34 (0.41–13.32) | |
| Property damage by the 2004 earthquake | P for trend = 0.6787 | ||
| Not damaged | 4/59 (6.8 %) | 1 (Ref.) | |
| Partially damaged | 19/372 (5.1 %) | 1.00 (0.31–3.25) | |
| Half or largely destroyed | 2/72 (2.8 %) | 0.97 (0.13–7.35) | |
| Completely destroyed | 1/26 (3.8 %) | 0.98 (0.04–21.84) | |
aAdjusted for sex and age except for predictor variables of “sex” and “age.” “Sex” and “age” were adjusted for age and sex, respectively
bEquivalent to Japanese sake (1 gou of sake is equivalent to about 27-g ethanol)