Table 4.
Change in Performance in Incentive and Control Groups for Medicaid (non-HMO) and Uninsured Patients
| Baseline Performance Adjusteda % (95% CI) |
End of Study Performance Adjusteda % (95% CI) |
Between Group Differences in Performance Change | |||||
|---|---|---|---|---|---|---|---|
| Controlb | Incentiveb | Controlb | Incentiveb | Absolute Adjusteda Change in Incentive – Change in Control | Adjusteda Odds Ratio, Interaction Term for Study Group and Study Year (95%CI)c | P valuec | |
| Aspirin therapy, with IVD or DM | 42.0% (31.8–52.1) | 39.4% (30.7–48.2) | 49.6% (40.2–59.0) | 56.4% (48.0–64.8) | 9.4% (−2.0–20.8%) | 1.46 (0.92–2.33) | 0.11 |
| Blood pressure control, no IVD or DM | 32.4% (20.4–44.5) | 45.1% (32.7–57.6) | 38.5% (26.2–50.8) | 58.1% (46.2–70.1) | 7.0% (−2.6–16.6%) | 1.30 (0.86–1.96) | 0.22 |
| Blood pressure control, with IVD | 61.8% (27.3–96.3) | 65.6% (35.1–96.2) | 56.3% (24.6–87.9) | 65.2% (39.3–91.2) | 5.2% (−37.3–47.6%) | 1.23 (0.20–7.52) | 0.81 |
| Blood pressure control, with DM | 15.1% (6.9–23.2) | 21.4% (12.7–30.1) | 13.5% (6.7–20.4) | 30.5%(21.1–40.0) | 10.8% (−0.6–22.1%) | 1.84 (0.82–4.14) | 0.14 |
| Blood pressure control, with IVD or DM | 21.2% (11.3–31.2) | 26.4% (16.3–36.5) | 18.8% (10.3–27.4) | 37.0% (26.2–47.8) | 12.9% (1.0–24.9%) | 1.90 (0.96–3.75) | 0.07 |
| Cholesterol control | 91.2% (85.6–96.8) | 90.5% (85.7–95.3) | 92.2% (89.2–95.2) | 91.2% (88.2–94.2) | −0.3% (−7.5–6.8%) | 0.95 (0.40–2.28) | 0.91 |
| Smoking cessation interventiond | 8.42% (2.1–14.8) | 11.3% (3.6–19.0) | 17.1% (6.4–27.8) | 27.9% (13.5–42.2) | 7.9% (−2.7–18.5%) | 1.35 (0.74–2.47) | 0.32 |
The absolute between-group differences in performance change between the Incentive and Control groups indicate whether the incentive overall changed the performance on each measure. IVD: ischemic vascular disease; HTN: hypertension; DM: diabetes mellitus.
All values are adjusted for clustering within clinics using mixed effects logistic regression modeling. Unadjusted values and numerators and denominators are in eTable 2. The statistical model creates odds ratios and we change this to more easily interpreted adjusted percentages using the predicted estimates from the model.
Baseline rates did not differ between control vs. intervention practices (p>0.05 for all).
Odds ratios and p-values are for the interaction term of study group and study year, with positive values indicating that the incentive group had greater improvement compared to baseline than the control group and negative values indicating that the control group had greater improvement compared to baseline than the incentive group. The p-values in the last column indicate whether the effects are statistically significant.
Smoking cessation interventions: For patients ages 18 years or older identified as current smokers, receipt of cessation counseling, referral for counseling, or prescription or increase dose of a cessation aid, documented in the EHR.