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Clinical trials

Subgroup analyses in randomized trials—more rigour needed

An analysis of reports from phase III trials (published between 2011 and 2013) investigating patients with solid tumours found widespread failings in both the conduct and reporting of subgroup analyses. Readers might well be misled by such analyses. Editors should, therefore, implement policies to reduce the risk of publishing misleading results.

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  1. Zhang, S., Liang, F., Li, W. & Hu, X. Subgroup analyses in reporting of phase III clinical trials in solid tumors. J. Clin. Oncol. 33, 1697–1702 (2015).

    Article  Google Scholar 

  2. Chan, A.-W., Hróbjartsson, A., Haahr, M. T., Gøtzsche, P. C. & Altman, D. G. Empirical evidence for selective reporting of outcomes in randomized trials: Comparison of protocols to published articles. JAMA 291, 2457–2465 (2004).

    Article  CAS  Google Scholar 

  3. Dwan, K. et al. Evidence for the selective reporting of analyses and discrepancies in clinical trials: a systematic review of cohort studies of clinical trials. PLoS Med. 11, e1001666 (2014).

    Article  Google Scholar 

  4. Kasenda, B. et al. Subgroup analyses in randomised controlled trials: cohort study on trial protocols and journal publications. BMJ 349, g4539 (2014).

    Article  Google Scholar 

  5. Kaufman, J. S. & MacLehose, R. F. Which of these things is not like the others? Cancer 119, 4216–4222 (2013).

    Article  Google Scholar 

  6. Moher, D. et al. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. BMJ 340, c869 (2010).

    Article  Google Scholar 

  7. Pocock, S. J., Hughes, M. D. & Lee, R. J. Statistical problems in the reporting of clinical trials: a survey of three medical journals. N. Engl. J. Med. 317, 426–432 (1987).

    Article  CAS  Google Scholar 

  8. Yusuf, S., Wittes, J., Probstfield, J. & Tyroler, H. A. Analysis and interpretation of treatment effects in subgroups of patients in randomised clinical trials. JAMA 266, 93–98 (1991).

    Article  CAS  Google Scholar 

  9. Boutron, I., Dutton, S., Ravaud, P. & Altman, D. G. Reporting and interpretation of randomized controlled trials with statistically nonsignificant results for primary outcomes. JAMA 303, 2058–2064 (2010).

    Article  CAS  Google Scholar 

  10. Sun, X. et al. Credibility of claims of subgroup effects in randomised controlled trials: systematic review. BMJ 344, e1553 (2012).

    Article  Google Scholar 

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Correspondence to Douglas G. Altman.

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Altman, D. Subgroup analyses in randomized trials—more rigour needed. Nat Rev Clin Oncol 12, 506–507 (2015).

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