3 Topic Commentaries

Trial Exclusions May Skew RA Drug Comparisons

• 

  Eliza F. Chakravarty, MD, MS

  Rheumatology

  •

  Stanford University School of Medicine

  RCTs address critically important biases of nonrandom assignment and unblinded observation with excellent internal validity, but they are limited by short periods of observation, relatively small sample sizes, the narrow generalizability of results, an inability to address many important patient-oriented questions, and a lack of desirable comparator groups.

  Source
• 

  Chunhua Weng, PhD

  Biomedical/Clinical Research Informatics

  •

  Columbia University Vagelos College of Physicians and Surgeons

  “When a study is designed, investigators may copy and paste clinical research eligibility criteria from existing study protocols or consulted their mentors or colleagues,” she says. “The problem is that a lot of the researchers converged to study similar population subgroups and, unwittingly, biased their studies against other populations without a good clinical justification.”

  Source
• 

  Philippe Ravaud, MD, PhD

  Clinical Epidemiology

  •

  Assistance Publique–Hôpitaux de Paris and Université Paris Descartes

  Head-to-head trials of biologic DMARDs are still exceptions. Exposing patients in control arms who had a previous partial response or nonresponse to an inadequate treatment could lead to irreversible deterioration in condition.

  Source