Segmented regression estimates and associated 95% confidence intervals for 155 754 patients qualifying for incentives during the study period
| Variable | Mean no. of primary care contacts per month | Proportion of visits to usual provider of care | Hospital admissions, monthly rate per 1000 patients | Mean monthly cost per patient, 2010/11 ($Can) | ||
|---|---|---|---|---|---|---|
| Total | Via the emergency department | For targeted conditions | ||||
| Intercept 24 months before incentive billing* | 1.10 (1.09 to 1.11) | 0.776 (0.770 to 0.781) | 28.3 (28.1 to 28.5) | 18.5 (18.1 to 19.0) | 16.0 (15.9 to 16.1) | 588.20 (581.39 to 595.01) |
| Preincentive trend† | 0.0020 (0.0015 to 0.0025) | −0.0008 (−0.0012 to 0.0004) | 0.002 (−0.011 to 0.014) | 0.023 (−0.006 to 0.052) | 0.037 (0.029 to 0.045) | 2.50 (2.02 to 2.99) |
| Change in level after incentive introduction‡ | 0.019 (0.009 to 0.030) | −0.0054 (−0.0128 to 0.0019) | 0.50 (0.23 to 0.77) | 0.51 (−0.06 to 1.08) | 0.07 (−0.10 to 0.23) | 35.81 (25.85 to 45.78) |
| Change in trend after incentive introduction§ | −0.0003 (−0.0010 to 0.0004) | 0.0014 (0.0008 to 0.0019) | 0.077 (0.063 to 0.091) | 0.04099 (0.00007 to 0.08191) | 0.037 (0.029 to 0.045) | 0.17 (−0.41 to 0.76) |
| Mean monthly change¶ | 0.016 (−0.047 to 0.078) | 0.012 (−0.001 to 0.024) | 1.46 (0.04 to 2.89) | 1.0 (−0.1 to 2.2) | 0.5 (−0.8 to 1.9) | 37.98 (−0.20 to 76.17) |
↵* Model fit value 24 months before incentive introduction.
↵† Slope or rate of change in the outcome over time, before incentive introduction.
↵‡ One-time increase or decrease in the outcome immediately following incentive introduction.
↵§ Change in slope after incentive introduction relative to the preincentive trend.
↵¶ The mean monthly change is the total change over the 24-month follow-up period (i.e., the area between the line fit to the points before incentive introduction projected forward and the line fit to points after incentive introduction), divided by 24 to reflect the monthly mean.