Table 3:

Univariate and multivariate effects of depression on 2-year outcomes

VariableMean length of stay, IRR (95% CI)*Total length of stay, IRR (95% CI)No. of hospital admissions, IRR (95% CI)
UnivariateMultivariateUnivariateMultivariateUnivariateMultivariate
Depression†1.32 (1.13–1.53)1.25 (1.06–1.48)1.76 (1.47–2.12)1.65 (1.36–2.01)1.30 (1.15–1.47)1.22 (1.07–1.39)
Age1.16 (1.10–1.23)1.27 (1.18–1.36)1.07 (1.02–1.13)
Education level0.99 (0.94–1.04)0.96 (0.91–1.02)0.96 (0.92–1.01)
Duke Social Support Index tertiles0.98 (0.92–1.04)1.01 (0.94–1.09)1.01 (0.96–1.07)
Smoking0.94 (0.84–1.07)0.82 (0.72–0.94)0.88 (0.80–0.98)
Charlson index (weighted)1.02 (0.99–1.04)1.08 (1.05–1.11)1.05 (1.03–1.07)

  • Note: CI = confidence interval, GDS-15 = 15-item Geriatric Depression Scale, IRR = incidence rate ratio.

  • ↵* Incidence rate ratios gained from zero-inflated negative binomial regressions.

  • ↵† No clinically significant depression = GDS-15 score < 7; clinically significant depression = GDS-15 score ≥ 7.