The FM-TIPS trial, a study supported by the NIH HEAL Initiative, is employing an interim reassessment of sample size to ensure the accuracy and validity of its findings. This pragmatic trial is focused on evaluating the effectiveness of transcutaneous electrical nerve stimulation (TENS) combined with routine physical therapy for reducing movement-evoked pain in patients with fibromyalgia.
Interim Sample Size Reassessment
Cluster randomized trials, like FM-TIPS, require careful consideration of potential correlations between clusters, often necessitating the estimation of intraclass correlation when determining the target sample size. According to a new case study published in the Living Textbook of Pragmatic Clinical Trials, the FM-TIPS researchers are using interim data collected during the trial to reassess the sample size. This approach is particularly useful when preliminary data are unavailable at the time of study design.
FM-TIPS Trial Details
The FM-TIPS trial is comparing the combination of TENS and physical therapy to physical therapy alone in patients with fibromyalgia. The primary outcome is the change in movement-evoked pain. The trial is supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases through the NIH HEAL Initiative.
Expert Perspectives
The case study detailing the reassessment methodology involves collaboration between members of the FM-TIPS study team and leaders of the NIH Collaboratory’s Biostatistics and Study Design Core. Key contributors include statisticians and biostatisticians from the University of Iowa, the University of Alabama at Birmingham, the University of Washington, and Duke University.
