Table 2.
Sample Characteristics of Depressive Symptoms, Cognition (MMSE Score), Sleep Quality and Covariates
| Variables | 2008 | n = 16,209 | 2011 | n = 8223 | 2014 | n = 5111 | 2018 | n = 2365 |
|---|---|---|---|---|---|---|---|---|
| Mean/% | SD | Mean/% | SD | Mean/% | SD | Mean/% | SD | |
| Age (65–105 years) | 87.05 | 11.09 | 85.73 | 10.65 | 85.13 | 9.76 | 85.38 | 8.03 |
| Sex | ||||||||
| Male | 42.81 | 45.30 | 46.35 | 46.09 | ||||
| Female | 57.19 | 54.70 | 53.65 | 53.91 | ||||
| Education | 2.01 | 3.39 | 2.35 | 3.56 | 2.53 | 3.56 | 2.95 | 3.89 |
| Marriage statue | ||||||||
| Married | 69.73 | 63.70 | 60.74 | 60.26 | ||||
| Unmarried | 30.27 | 36.30 | 39.26 | 39.74 | ||||
| Living arrangement | ||||||||
| Living with others | 84.45 | 83.33 | 81.88 | 78.85 | ||||
| Living alone | 15.55 | 16.67 | 18.12 | 18.77 | ||||
| Smoking | ||||||||
| Current smoker | 17.19 | 18.08 | 17.41 | 15.63 | ||||
| Current no smoking | 82.81 | 81.92 | 82.59 | 84.37 | ||||
| Drinking | ||||||||
| Current drinker | 16.95 | 17.07 | 15.74 | 14.46 | ||||
| Current no drinking | 83.05 | 82.93 | 84.26 | 85.54 | ||||
| Physical exercise | ||||||||
| Regular physical exercise | 27.73 | 36.45 | 32.19 | 32.35 | ||||
| No physical exercise | 72.26 | 63.55 | 67.81 | 67.65 | ||||
| Frequency of social activity | 4.75 | 0.80 | 4.69 | 0.88 | 4.67 | 0.90 | 4.74 | 0.83 |
| Activities of daily living | 6.97 | 2.38 | 7.21 | 2.64 | 7.14 | 2.60 | 7.00 | 2.45 |
| Depressive symptom | 11.75 | 2.55 | 11.29 | 3.37 | 11.36 | 3.44 | 11.84 | 2.41 |
| Cognitive function | 17.76 | 6.19 | 18.34 | 5.93 | 19.24 | 5.08 | 19.00 | 5.44 |
| Sleep quality | 2.36 | 0.95 | 2.35 | 0.97 | 2.39 | 0.96 | 2.50 | 1.01 |