Table 3.
Association Between Level of Depressive Symptoms and Subsequent Disability Burden
| Odds Ratio (95% Confidence Interval) |
|||||
| Model 1 (unadjusted) | Model 2 | Model 3 | Model 4 | Model 5 (fully adjusted) | |
| Mild disability vs no disability | |||||
| Level of depressive symptoms* | |||||
| Low | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Moderate | 1.02 (0.96–1.08) | 1.02 (0.94–1.02) | 1.24 (1.14–1.35) | 1.37 (1.26–1.50) | 1.30 (1.18–1.43) |
| High | 1.25 (1.15–1.35) | 1.26 (1.14–1.39) | 1.78 (1.60–1.98) | 1.85 (1.65–2.06) | 1.68 (1.50–1.88) |
| Time interval | 1.35 (1.33–1.37) | 1.19 (1.16–1.22) | 1.08 (1.05–1.11) | 1.07 (1.04–1.10) | 1.06 (1.03–1.09) |
| Age | 1.17 (1.14–1.18) | 1.18 (1.16–1.20) | 1.09 (1.07–1.11) | 1.11 (1.09–1.13) | |
| Female sex | 1.34 (1.10–1.63) | 1.64 (1.35–1.99) | 1.39 (1.17–1.66) | 1.45 (1.21–1.74) | |
| Race | 0.65 (0.48–0.87) | 0.93 (0.68–1.26) | 1.14 (0.86–1.49) | 1.18 (0.89–1.56) | |
| Education (y) | 1.01 (0.98–1.05) | 1.13 (1.09–1.16) | 1.05 (1.02–1.08) | 1.06 (1.02–1.08) | |
| Number of chronic conditions | 1.24 (1.18–1.30) | 1.13 (1.08–1.19) | 1.15 (1.10–1.21) | ||
| MMSE score† | 0.87 (0.86–0.89) | 0.87 (0.85–0.88) | 0.87 (0.86–0.89) | ||
| Smoking status | 0.93 (0.78–1.10) | 1.08 (0.91–1.29) | |||
| Physical activity‡ | 0.98 (0.97–0.99) | 0.98 (0.97–0.99) | |||
| BMI | 1.00 (0.99–1.01) | 0.99 (0.97–0.99) | |||
| Antidepressant medication use | 1.46 (1.29–1.66) | ||||
| Severe disability vs no disability | |||||
| Level of depressive symptoms* | |||||
| Low | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Moderate | 1.03 (0.96–1.11) | 1.04 (0.94–1.14) | 0.98 (0.84–1.12) | 1.22 (1.06–1.40) | 1.06 (0.92–1.22) |
| High | 1.59 (1.45–1.75) | 1.70 (1.51–1.92) | 2.14 (1.84–2.50) | 2.58 (2.22–2.99) | 2.05 (1.76–2.39) |
| Time interval | 1.53 (1.50–1.57) | 1.46 (1.41–1.52) | 1.35 (1.29–1.42) | 1.26 (1.22–1.32) | 1.26 (1.21–1.32) |
| Age | 1.21 (1.19–1.24) | 1.19 (1.16–1.21) | 1.06 (1.04–1.08) | 1.08 (1.06–1.10) | |
| Female sex | 1.05 (0.88–1.26) | 1.23 (1.00–1.50) | 1.18 (0.98–1.42) | 1.22 (1.01–1.47) | |
| Race | 0.88 (0.65–1.18) | 1.34 (0.96–1.87) | 1.04 (0.79–1.37) | 1.12 (0.85–1.49) | |
| Education (y) | 1.01 (0.98–1.04) | 1.29 (1.24–1.34) | 1.12 (1.08–1.15) | 1.11 (1.08–1.15) | |
| Number of chronic conditions | 1.63 (1.54–1.73) | 1.30 (1.23–1.37) | 1.35 (1.28–1.43) | ||
| MMSE score† | 0.76 (0.74–0.77) | 0.76 (0.75–0.78) | 0.78 (0.76–0.79) | ||
| Smoking status | 1.27 (1.05–1.52) | 1.46 (1.21–1.77) | |||
| Physical activity‡ | 0.97 (0.96–0.98) | 0.98 (0.97–0.99) | |||
| BMI | 1.00 (0.98–1.01) | 0.98 (0.96–0.99) | |||
| Antidepressant medication use | 2.29 (1.97–2.66) | ||||
Notes: BMI = Body mass index; MMSE = Mini-Mental State Examination.
*
Determined using the Center for Epidemiological Studies-Depression scale; low = score ≤9; moderate = score 10–19; high = score ≥20.
†
Assessed with the MMSE.
‡
Assessed with the Physical Activity Scale for the Elderly.