Failure to address potential bias in non-randomised controlled clinical trials may cause lack of evidence on patient-reported outcomes: a method study

BMJ Open. 2014 Jun 4;4(6):e004720. doi: 10.1136/bmjopen-2013-004720.

Abstract

Objectives: We conducted a workup of a previously published systematic review and aimed to analyse why most of the identified non-randomised controlled clinical trials with patient-reported outcomes did not match a set of basic quality criteria.

Setting: There were no limits on the level of care and the geographical location.

Participants: The review evaluated permanent interstitial low-dose rate brachytherapy in patients with localised prostate cancer and compared that intervention with alternative procedures such as external beam radiotherapy, radical prostatectomy and no primary therapy.

Primary outcome measure: Fulfilment of basic inclusion criteria according to a Participants, Interventions, Comparisons, Outcomes (PICO) framework and accomplishment of requirements to contain superimposed risk of bias.

Results: We found that 21 of 50 excluded non-randomised controlled trials did not meet the PICO inclusion criteria. The remaining 29 studies showed a lack in the quality of reporting. The resulting flaws included attrition bias due to loss of follow-up, lack of reporting baseline data, potential confounding due to unadjusted data and lack of statistical comparison between groups.

Conclusions: With respect to the reporting of patient-reported outcomes, active efforts are required to improve the quality of reporting in non-randomised controlled trials concerning permanent interstitial low-dose rate brachytherapy in patients with localised prostate cancer.

MeSH terms

  • Bias*
  • Controlled Clinical Trials as Topic / methods*
  • Controlled Clinical Trials as Topic / statistics & numerical data*
  • Humans
  • Male
  • Patient Outcome Assessment
  • Prostatic Neoplasms / therapy*
  • Research Design / statistics & numerical data*
  • Self Report*