Table 4. Logistic regressions of decline in IADL functioning between 2000 and 2002.
| Model 0 |
Model 1 |
Model 2 |
Model 3 |
|||||
|---|---|---|---|---|---|---|---|---|
| Variable | OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI |
| Care-giving hours in 2000 (Reference case, none) | ||||||||
| <14 | 1.8 | 1.3–2.5 | 1.2 | 0.90–1.9 | 1.2 | 0.85–1.8 | 1.0 | 0.70–1.6 |
| ≥14 | 2.0 | 1.5–2.7 | 1.1 | 0.82–1.5 | 1.0 | 0.77–1.4 | 0.94 | 0.66–1.3 |
| Age group (years) (Reference case, <65) | ||||||||
| 65–74 | 1.7 | 1.4–2.0 | 1.6 | 1.3–2.0 | 1.7 | 1.4–2.0 | 1.5 | 1.2–1.9 |
| ≥75 | 4.4 | 3.5–5.5 | 4.3 | 3.4–5.4 | 4.3 | 3.4–5.4 | 3.5 | 2.8–4.5 |
| Gender (Reference case, Men) | ||||||||
| Women | 0.82 | 0.69–0.97 | 0.87 | 0.73–1.0 | 0.77 | 0.65–0.92 | 0.73 | 0.59–0.90 |
| Race (Reference case, White) | ||||||||
| Black | 1.6 | 1.3–2.0 | 1.2 | 0.94–1.4 | 1.1 | 0.90–1.4 | 1.0 | 0.80–1.3 |
| Other | 1.3 | 0.75–2.2 | 1.2 | 0.73–1.9 | 1.1 | 0.71–1.8 | 1.2 | 0.70–2.1 |
| Education (years) (Reference case, <12) | ||||||||
| 12 | 0.44 | 0.36–0.54 | 0.59 | 0.47–0.74 | 0.63 | 0.49–0.79 | 0.75 | 0.58–0.96 |
| >12 | 0.36 | 0.29–0.45 | 0.57 | 0.45–0.71 | 0.65 | 0.51–0.83 | 0.80 | 0.62–1.0 |
| Net worth US$ (quartile) (Reference case, ≤42,900) | ||||||||
| 42,901–129,000 | 0.70 | 0.56–0.88 | 0.78 | 0.62–0.98 | 0.85 | 0.67–1.1 | 1.0 | 0.81–1.3 |
| 129,001–310,900 | 0.51 | 0.37–0.70 | 0.58 | 0.42–0.80 | 0.66 | 0.48–0.90 | 0.87 | 0.64–1.2 |
| ≥310,901 | 0.38 | 0.29–0.51 | 0.47 | 0.35–0.64 | 0.61 | 0.46–0.83 | 0.85 | 0.63–1.1 |
| Health-related behaviours | ||||||||
| Smokes cigarettes now | 1.3 | 1.0–1.6 | 1.5 | 1.2–1.9 | 1.5 | 1.2–1.8 | ||
| Drinks alcohol | 0.44 | 0.34–0.56 | 0.54 | 0.41–0.72 | 0.62 | 0.47–0.81 | ||
| Takes vigorous exercise | 0.40 | 0.33–0.48 | 0.50 | 0.41–0.61 | 0.61 | 0.50–0.75 | ||
| Body Mass Index (Reference case, 18.5–24.9 ‘normal’) | ||||||||
| <18.5 | 2.3 | 1.6–3.4 | 1.7 | 1.1–2.7 | 1.6 | 0.96–2.6 | ||
| 25.0–29.9 | 1.0 | 0.85–1.2 | 1.1 | 0.89–1.3 | 1.1 | 0.88–1.3 | ||
| ≥30.0 | 1.2 | 0.99–1.5 | 1.3 | 1.0–1.7 | 1.2 | 0.91–1.5 | ||
| Health condition | ||||||||
| High blood pressure | 1.7 | 1.4–2.0 | 1.1 | 0.91–1.3 | ||||
| Diabetes | 2.2 | 1.9–2.6 | 1.4 | 1.1–1.7 | ||||
| Lung disease | 1.9 | 1.6–2.4 | 1.1 | 0.86–1.5 | ||||
| Heart disease | 2.2 | 1.9–2.6 | 1.3 | 1.0–1.6 | ||||
| Cancer | 1.5 | 1.2–1.8 | 1.1 | 0.85–1.3 | ||||
| Stroke | 3.9 | 3.2–4.9 | 1.9 | 1.5–2.5 | ||||
| Psychiatric problem | 2.9 | 2.5–3.4 | 2.2 | 1.8–2.5 | ||||
| Incontinence | 2.1 | 1.7–2.5 | 1.5 | 1.2–1.8 | ||||
| Dementia | 7.0 | 5.5–8.9 | 3.4 | 2.7–4.3 | ||||
| Spouse’s Nagi function (Reference case, 0) | ||||||||
| 1–3 | 1.5 | 1.2–1.8 | 1.1 | 0.85–1.4 | ||||
| 4–6 | 2.3 | 1.8–2.9 | 1.4 | 1.1–1.9 | ||||
| 7–9 | 3.3 | 2.3–4.7 | 1.5 | 0.97–2.2 | ||||
Notes: OR odds ratio. 95% CI 95 per cent confidence interval of OR. The data source was the 2000 and 2002 Health and Retirement Study. Data were weighted and adjusted for the complex sampling design. Model 0 included care-giving hours (with zero as the reference case). Model 1 included Model 0 variables plus age, race, sex, net worth and education. Model 2 included Model 1 variables plus current smoker, drinks alcohol, participates in vigorous physical activity and BMI. Model 3 included Model 2 variables plus the nine medical conditions and Nagi functioning variables.