This is great – thanks for the bibliography!

There is another paper that critically exams a specific trial and is a very useful description of some of the problems with sub-groups and secondary outcomes:

Freemantle, N. (2005). How well does the evidence on pioglitazone back up researchers' claims for a reduction in macrovascular events?. BMJ 331: 836-838.  http://www.bmj.com/cgi/content/extract/331/7520/836

Regards,

Martin

PS. On a separate but related theme there is also some interesting debate about the use and abuse of composite end points in a recent BMJ:

Composite and surrogate outcomes in randomised controlled trials
Nick Freemantle and Mel Calvert
BMJ 2007; 334: 756-757. [Extract]

Problems with use of composite end points in cardiovascular trials: systematic review of randomised controlled trials
Ignacio Ferreira-González, Gaiet Permanyer-Miralda, Antònia Domingo-Salvany, et al.
BMJ 2007; 334: 786. [Abstract]

From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Nino Cartabellotta
Sent: 09 May 2007 21:48
To: [log in to unmask]
Subject: R: Subgroup analyses - are they ever best evidence

Dear members of EBH list,

This is our bibliography about subgroup analysis (with link to full text)

Best regards

Nino Cartabellotta

Director

Centro Studi GIMBE^®

Via Amendola 2 - 40121 Bologna

Tel. (+39) 051 5883920 

Fax (+39) 051 3372195

www.gimbe.org

• Lagakos SW. The challenge of subgroup analyses--reporting without distorting. N Engl J Med 2006;354:1667-9.

· Parker AB, Naylor CD. Interpretation of subgroup results in clinical trial publications: insights from a survey of medical specialists in Ontario, Canada. Am Heart J 2006;151:580-8.

· Hernandez AV, Boersma E, Murray GD, et al. Subgroup analyses in therapeutic cardiovascular clinical trials: are most of them misleading? Am Heart J 2006;151:257-64.

· Rothwell PM. Subgroup analysis in randomised controlled trials: importance, indications, and interpretation. Lancet 2005;365:176-86

· Schulz KF, Grimes DA. Multiplicity in randomised trials II: subgroup and interim analyses. Lancet 2005;365:1657-61

· Rothwell PM, Mehta Z, Howard SC, et al. 3. From subgroups to individuals: general principles and the example of carotid endarterectomy. Lancet 2005;365:256-65

• Simes RJ, Gebski VJ, Keech AC. Subgroup analysis: application to individual patient decisions. Med J Aust 2004;180:467-9
• Brookes ST, Whitely E, Egger M, et al. Subgroup analyses in randomized trials: risks of subgroup-specific analyses; power and sample size for the interaction test. J Clin Epidemiol 2004;57:229-36
• Cook DI, Gebski VJ, Keech AC. Subgroup analysis in clinical trials. Med J Aust 2004;180:289-91
• Brookes ST, Whitley E, Peters TJ, et al. Subgroup analyses in randomised controlled trials: quantifying the risks of false-positives and false-negatives. Health Technol Assess 2001;5:1-56
• Freemantle N. Interpreting the results of secondary end points and subgroup analyses in clinical trials: should we lock the crazy aunt in the attic? BMJ 2001;322:989-91
• Assmann SF, Pocock SJ, Enos LE, et al. Subgroup analysis and other (mis)uses of baseline data in clinical trials. Lancet 2000;355:1064-9
• Horton R. From star signs to trial guidelines. Lancet 2000;355:1033-4
• Parker AB, Naylor CD. Subgroups, treatment effects, and baseline risks: some lessons from major cardiovascular trials. Am Heart J 2000;139:952-961.
• Adams KF Jr. Post hoc subgroup analysis and the truth of a clinical trial. Am Heart J 1998;136:753-8
• Detsky AS, Naglie IG. Subgroup analyses: primary and secondary. ACP J Club 1995;122(3):A12-A14
• Oxman AD, Guyatt GH. A consumer's guide to subgroup analyses. Ann Intern Med 1992;116:78-84 [abstract]
• Yusuf S, Wittes J, Probstfield J, Tyroler HA. Analysis and interpretation of treatment effects in subgroups of patients in randomized clinical trials. JAMA 1991;266:93-8 [abstract]
• Bulpitt CJ. Subgroup analysis. Lancet 1988;ii:31-4.