Table 2 Results of bivariate, multivariate, and stepwise logistic regressions: relative risks for a decline in higher-level ADLs by severe depression symptoms (bivariate and multivariate models) or by selected factors (stepwise model)

Severe depression symptoms (vs. not severe/none)—bivariate model

2.8 (1.5–5.1)

5.0 (2.6–9.6)

2.0 (0.9–4.6)

1.8 (0.9–3.8)

Severe depression symptoms (vs. not severe/none)—multivariate model

3.2 (1.6–6.3)

6.8 (3.1–14.8)

1.8 (0.75–4.4)

1.9 (0.9–4.2)

Explanatory variables selected by stepwise model

  Severe depression symptoms (vs. not severe/none)

3.4 (1.74–6.5)

7.6 (3.6–16.1)

Not selected

2.2 (1.05–4.6)

  Physical health (PCS score^a) = high (vs. low)

0.5 (0.26–0.97)