Hi, friend! Based on your previous suggestion, may I conclude that small program evaluations have limited value?

No problem.

Thanks!

If you are considering conducting a study of impacts, you should first calculate whether the sample is large enough to detect effects that are moderate enough in size to be plausible but large enough that stakeholders would consider adopting the intervention if the effects were demonstrated. Your assessment of statistical power must account for the clustering of patient outcomes within practices. In most cases, evaluations of primary care interventions require surprisingly large numbers of practices, regardless of how many patients are served, to be confident that plausible and adequate-sized effects on cost and utilization measures will be shown to be statistically significant. Your evaluation would likely need to include more than 50 intervention practices (unless the practice patterns are very similar) to be confident that observed differences in outcomes are true effects of the intervention. Most small pilots will not be able to detect effects on cost because they do not have enough practices to detect such effects. Devoting resources to an impact study with a small number of practices.