Table 1.
Characteristics of Study Population
| Matched group | Matched group | Matched group | ||||
|---|---|---|---|---|---|---|
| Continuous users (n = 7195) | Brand-brand switchers (n = 7195) | Continuous users (n = 6824) | Brand-generic switchers (n = 6824) | Continuous users (n = 5344) | Multiple switchers (n = 5344) | |
| Mean age (SD) | 52.9 (13.3) | 52.5 (12.8) | 53.7 (13.4) | 51.5 (13.3) | 52.4 (13.3) | 52.6 (13.7) |
| Patients in each group, % | ||||||
| Age-group, y | ||||||
| 0–17 | 1.1 | 0.7 | 1.2 | 1.2 | 1.1 | 1.1 |
| 18–34 | 7.8 | 7.7 | 6.1 | 8.6 | 7.7 | 8.0 |
| 35–44 | 16.9 | 17.9 | 15.6 | 18.3 | 17.5 | 17.0 |
| 45–54 | 26.6 | 28.9 | 27.7 | 29.6 | 28.7 | 29.2 |
| 55–64 | 31.4 | 29.9 | 31.1 | 29.5 | 29.6 | 28.1 |
| ≥65 | 16.3 | 14.9 | 18.3 | 13.3 | 15.3 | 16.6 |
| Sex | ||||||
| Male | 16.7 | 17.3 | 18.7 | 18.1 | 15.1 | 15.4 |
| Female | 83.3 | 82.7 | 81.3 | 81.9 | 84.9 | 84.6 |
| Census regiona | ||||||
| Northeast | 66.3 | 66.4 | 66.3 | 62.9 | 66.3 | 65.1 |
| South | 10.6 | 10.8 | 6.1 | 10.5 | 7.7 | 8.0 |
| Midwest | 8.5 | 7.9 | 9.0 | 10.7 | 9.7 | 9.1 |
| West | 6.6 | 6.4 | 11.6 | 8.5 | 9.1 | 10.2 |
| Other/missing | 8.0 | 8.5 | 7.1 | 7.4 | 7.2 | 7.7 |
| Insurance plan | ||||||
| HMO | 46.8 | 47.7 | 32.8 | 27.2 | 40.8 | 40.3 |
| Indemnity | 5.2 | 4.8 | 4.1 | 2.2 | 4.3 | 4.9 |
| POS | 10.2 | 9.8 | 10.4 | 5.3 | 10.4 | 11.0 |
| PPO | 34.3 | 34.3 | 45.6 | 63.1 | 39.0 | 37.5 |
| Other/missing | 3.4 | 3.5 | 7.1 | 2.2 | 5.5 | 6.4 |
| Payer | ||||||
| Commercial | 89.7 | 90.6 | 89.3 | 94.3 | 89.7 | 88.7 |
| Medicare | 7.3 | 6.2 | 4.7 | 3.9 | 5.4 | 5.9 |
| Medicaid | 2.9 | 3.2 | 5.9 | 1.8 | 4.8 | 5.4 |
| Comorbiditiesb | ||||||
| Depression | 7.4 | 8.0 | 7.2 | 7.4 | 7.5 | 7.7 |
| Hyperlipidemia | 23.5 | 24.7 | 26.6 | 27.1 | 24.4 | 23.1 |
| Arteriosclerosis | 4.3 | 4.7 | 4.7 | 4.6 | 3.4 | 4.4 |
| Angina | 0.9 | 1.0 | 0.9 | 1.1 | 0.7 | 1.0 |
| Hypertension | 22.8 | 25.3 | 25.0 | 25.4 | 23.2 | 24.9 |
| Heart attack | 0.4 | 0.5 | 0.4 | 0.2 | 0.3 | 0.6 |
| Stroke | 1.7 | 1.7 | 2.1 | 1.4 | 1.7 | 1.7 |
| Arrhythmia | 4.0 | 3.7 | 4.4 | 3.8 | 3.9 | 4.1 |
SD indicates standard deviation.
a
Each census region contains 2 to 3 census divisions, which was the unit used in matching.
b
Measured in the 6 months preindex.