Comparative effectiveness of colony-stimulating factors in febrile neutropenia prophylaxis: how results are affected by research design

Aims: To examine the impact of research design on results in two published comparative effectiveness studies. Methods: Guidelines for comparative effectiveness research have recommended incorporating disease process in study design. Based on the recommendations, we develop a checklist of considerations and apply the checklist in review of two published studies on comparative effectiveness of colony-stimulating factors. Both studies used similar administrative claims data, but different methods, which resulted in directionally different estimates. Results: Major design differences between the two studies include: whether the timing of intervention in disease process was identified and whether study cohort and outcome assessment period were defined based on this temporal relationship. Conclusion: Disease process and timing of intervention should be incorporated into the design of comparative effectiveness studies.