Table 3

Patients Screened or Screening Recommended, Chart Audit Data

MeasureControl Practices (n=11)Intervention Practices (n=12)
Odds of improvement
OR (95% CI)a0.82 (0.59 to 1.15)1.21 (0.87 to 1.68)
OR=1, P valueb.24.25
Breslow-Day, P value<.001.008
Ratio of ORsc1.47
Equal ORs, P value.11
Change in performance
Average difference of proportions (95% CI)d−0.05 (−0.23 to 0.13)0.04 (−0.08 to 0.15)
Change within group, P value.59.48
Intervention effect, P value.40
• CI=confidence interval. OR = odds ratio, interpreted as the odds of screening at follow-up relative to the odds of screening at baseline.

• a P value testing the null hypothesis of no improvement within group.

• b P value testing whether the odds of improvement are homogeneous across practices within a group.

• c Calculated as the odds of improvement under the intervention relative to the odds of improvement for the control group.

• d For each practice, change was measured as the proportion screened at follow-up minus the proportion screened at baseline.