Medium matters: modeling the impact of solid medium performance on tuberculosis trial sample size requirements

Int J Tuberc Lung Dis. 2016 May;20(5):600-4. doi: 10.5588/ijtld.15.0570.

Abstract

Setting: Two-month solid medium culture conversion is a commonly used, if suboptimal, endpoint for phase 2 anti-tuberculosis treatment trials.

Objective and design: To model the effect of the performance characteristics (sensitivity and contamination rate) of solid medium on required sample size for a two-arm clinical trial with 85% true (gold standard) culture conversion in the control and 95% in the experimental arm.

Results: Increasing sensitivity and decreasing contamination reduced the sample size from 239 subjects/arm (60% sensitivity, 30% contamination) to 138 subjects/arm (95% sensitivity, 1% contamination).

Conclusion: Optimizing solid medium has significant potential to reduce sample size and increase the efficiency of tuberculosis clinical trials.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antitubercular Agents / therapeutic use*
  • Bacteriological Techniques*
  • Clinical Trials, Phase II as Topic / methods*
  • Controlled Clinical Trials as Topic / methods*
  • Culture Media*
  • Endpoint Determination
  • Humans
  • Mycobacterium tuberculosis / drug effects*
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / isolation & purification
  • Predictive Value of Tests
  • Reproducibility of Results
  • Sample Size*
  • Time Factors
  • Treatment Outcome
  • Tuberculosis / diagnosis
  • Tuberculosis / drug therapy*
  • Tuberculosis / microbiology

Substances

  • Antitubercular Agents
  • Culture Media