Table III.

Factors associated with medication underuse among 384 physically frail US veterans aged ≥65 years at the time of discharge from 11 veterans’ hospitals, based on retrospective analysis of data from the Geriatric Evaluation and Management Drug Study.^17*

Risk Factor	Crude Odds Ratio (95% CI)	P	Adjusted Odds Ratio (95% CI)	P
Primary independent variables
No. of medications
≥9	1.08 (0.60–1.92)	0.81	0.95 (0.50–1.78)	0.86
5–8	1.13 (0.70–1.81)	0.62	1.07 (0.64–1.77)	0.81
0–4†			1.00
Unnecessary medication use	1.10 (0.73–1.66)	0.66	0.99 (0.65–1.53)	0.98
Charlson comorbidity index for every 1-point increase	1.11 (0.99–1.23)	0.07	1.13 (1.00–1.27)	0.04
Other independent variables
Sociodemographics
Age group, y
65–74†	1.00
75–85	1.21 (0.79–1.85)	0.37
>85	1.08 (0.34–3.41)	0.89
Male sex	3.90 (0.99–15.33)	0.05
White race	1.52 (0.97–2.38)	0.07	1.70 (1.06–2.71)	0.03
Married	1.22 (0.81–1.85)	0.34
Completed high school	0.95 (0.63–1.44)	0.81
Employed	0.43 (0.17–1.10)	0.08	0.40 (0.15–1.05)	0.06
Health status
≥1 Fall in last 3 months	1.14 (0.67–1.96)	0.63
Depression	0.90 (0.45–1.80)	0.77
Malnutrition	1.27 (0.81–1.99)	0.29
Fair or poor self-rated health	1.29 (0.85–1.97)	0.23
Need for help with ≥1 ADL	2.08 (1.24–3.49)	0.01	2.17 (1.27–3.71)	0.01
Access to health care
Primary hospital service
Medicine	0.68 (0.43–1.06)	0.09	0.61 (0.38–0.98)	0.04
Surgery†			1.00
Multiple prescribers	0.85 (0.33–2.15)	0.73

ADL = activity of daily living.

^*Hosmer-Lemeshow goodness-of-fit test (χ² = 11.9; df = 8;P = 0.16) suggests adequate model fit.³¹

^†Referent.