Table 2.
Factors Associated with Initiating a Fixed-Dose Combination Versus a Single Therapy
| Characteristic (ref: single therapy) | Unadjusted RR (95% CI) | Adjusted RR* (95% CI) |
|---|---|---|
| Demographic | ||
| Age (ref: <45 years) | ||
| 45–54 years | 1.44 (1.42–1.47) | 1.33 (1.31–1.35) |
| ≥55 years | 1.36 (1.34–1.38) | 1.31 (1.29–1.33) |
| Female (ref: no) | 1.02 (1.00–1.03) | 1.18 (1.16–1.19) |
| Region (ref: West) | ||
| South | 0.92 (0.89–0.95) | 1.36 (1.33–1.38) |
| Midwest | 1.45 (1.42–1.48) | 1.24 (1.21–1.27) |
| Northeast | 1.24 (1.21–1.27) | 0.89 (0.86–0.91) |
| Clinical (ref: no) | ||
| Alzheimer’s/Dementia | 0.47 (0.40–0.55) | 0.72 (0.61–0.84) |
| Congestive heart failure | 0.16 (0.10–0.26) | 0.52 (0.32–0.84) |
| Coronary artery disease | 0.08 (0.07–0.10) | 0.17 (0.14–0.22) |
| COPD/Asthma | 0.88 (0.84–0.92) | 1.12 (1.07–1.17) |
| Depression | 0.76 (0.73–0.78) | 0.91 (0.89–0.94) |
| Diabetes | 0.79 (0.77–0.81) | 0.82 (0.80–0.84) |
| Kidney disease | 0.58 (0.52–0.64) | 0.86 (0.78–0.94) |
| Liver disease | 0.71 (0.66–0.77) | 1.08 (1.01–1.16) |
| Peripheral vascular disease | 0.48 (0.39–0.57) | 0.72 (0.60–0.86) |
| Stroke/TIA | 0.32 (0.26–0.39) | 0.69 (0.56–0.85) |
| Health utilization | ||
| Hospitalized (ref: no) | 0.39 (0.37–0.41) | 0.63 (0.61–0.66) |
| No. unique drugs (ref: 1) | ||
| 2 | 0.86 (0.84–0.88) | 0.92 (0.90–0.94) |
| ≥3 | 0.66 (0.65–0.67) | 0.82 (0.81–0.84) |
| ≥2 outpatient visits (ref: ≤1) | 0.72 (0.71–0.74) | 0.79 (0.78–0.80) |
| Comorbidity score: ≥1 (ref: ≤0) | 0.55 (0.54–0.56) | 0.63 (0.62–0.64) |
| Prescription copay (ref: <$10.00) | ||
| ≥$10.00 | 1.15 (1.14–1.17) | 1.03 (1.01–1.05) |
Abbreviations: RR relative risk, CI confidence interval, COPD chronic obstructive pulmonary disease, TIA transient ischemic attack
*Includes all characteristics listed here