Table 2.
Characteristics of Claims Associated with the Intervention and Control Group in Each Analysis
| Model | ||||||
|---|---|---|---|---|---|---|
| Mailings and Advertising | Generic Sampling | Physician Incentive | ||||
| Variable | Intervention | Control | Intervention | Control | Intervention | Control |
| Dependent variables at baseline* | ||||||
| GDR (%) | 16.5 | 14.1 | 15.7 | 16.6 | 17.3 | 17.2 |
| Mail order GDR (%) | 20.7 | 19.2 | 19.0 | 21.0 | 20.3 | 21.4 |
| Retail GDR (%) | 16.2 | 13.5 | 15.5 | 16.3 | 17.1 | 16.8 |
| Claim characteristics† | ||||||
| ACE inhibitor (%) | 20.3 | 18.3 | 20.8 | 20.2 | 20.8 | 20.3 |
| α blocker (%) | 3.9 | 4.1 | 4.1 | 3.9 | 3.8 | 4.3 |
| Calcium channel blocker (%) | 20.5 | 18.9 | 20.4 | 20.5 | 18.9 | 18.4 |
| Oral hypoglycemic (%) | 20.5 | 19.6 | 23.3 | 20.2 | 22.8 | 23.3 |
| Proton pump inhibitor (%) | 18.1 | 19.7 | 18.1 | 18.1 | 18.3 | 17.5 |
| SNRI (%) | 5.0 | 6.1 | 3.3 | 5.1 | 3.8 | 4.4 |
| SSRI (%) | 11.7 | 13.4 | 10.0 | 11.9 | 11.6 | 11.8 |
| Copayment ratio‡ | 1.45 ± 1.06 | 1.39 ± 1.12 | 1.46 ± 1.09 | 1.45 ± 1.06 | 1.71 ± 1.21 | 1.65 ± 1.09 |
| Initial fill (%) | 16.5 | 15.5 | 12.6 | 16.9 | 14.0 | 14.8 |
| Spending per claim ($) | 64.9 ± 60.6 | 74.4 ± 70.6 | 65.8 ± 61.2 | 64.8 ± 60.5 | 61.9 ± 57.9 | 63.5 ± 60.0 |
| Member characteristics | ||||||
| Male (%) | 47.1 | 48.4 | 46.8 | 47.1 | 44.8 | 45.2 |
| Age (years) | 66.2 ± 13.9 | 65.5 ± 13.2 | 67.1 ± 13.1 | 66.1 ± 13.9 | 67.4 ± 12.8 | 67.2 ± 12.6 |
| Hourly employee (%) | 70.3 | 83.8 | 72.0 | 70.1 | 47.6 | 43.7 |
| National employer I (%) | 51.6 | 57.5 | 59.1 | 50.8 | 47.3 | 28.3 |
| National employer II (%) | 34.0 | 42.3 | 31.3 | 34.3 | 12.1 | 23.9 |
| Regional employer I (%) | 13.6 | 0.2 | 8.9 | 14.1 | 38.5 | 44.9 |
| Regional employer II (%) | 0.8 | – | 0.7 | 0.8 | 2.1 | 2.9 |
| Physician practice characteristics | ||||||
| Geographic area A (%) | – | – | – | – | 78.3 | 70.3 |
| Geographic area B (%) | – | – | – | – | 4.9 | 6.1 |
| Geographic area C (%) | – | – | – | – | 16.8 | 23.6 |
| Number of physicians | – | – | – | – | 252.7 ± 74.8 | 181.9 ± 27.6 |
| Employees' salaried (%) | – | – | – | – | 85.7 | 22.4 |
| Cohesiveness/leadership rating | – | – | – | – | 3.8 ± 1.2 | 3.8 ± 2.1 |
| Urban/rural location (%) | – | – | – | – | 81.7 | 100 |
| Per-member per-month spending ($) | – | – | – | – | 72.1 ± 26.4 | 46.6 ± 19.3 |
| Pharmacy characteristics | ||||||
| Pharmacy incentive payment per script ($) | 0.15 ± 0.20 | 0.11 ± 0.36 | 0.13 ± 0.15 | 0.16 ± 0.20 | 0.19 ± 0.23 | 0.18 ± 0.23 |
*
The baseline period is defined as the first 6 months of 2000, predating most of the interventions
†
The date of the claim was included in the model for the mailings and the advertising campaigns to improve the precision of the analysis, whereas in the models for the generic sampling and physician incentive programs it had to be included to ensure the validity of the inferences
‡
The mean ± standard deviation is presented for the copayment ratio and other continuous predictors
GDR, generic dispensing rate; SNRI, selective norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor