Lies, damn lies and statistics: errors and omission in papers submitted to INJURY 2010-2012

Introduction: Many reviews of published papers in the medical literature have reported errors in statistical methods and presentation.

Methods: 100 successive papers submitted to INJURY and sent for initial statistical review between December 2010 and January 2012 were analysed. The comments made on the papers were categorised and summarised.

Results: Suggestions for improvement were made for 90 of the papers. An inappropriate analysis was identified in 47. Other errors were seen in 45 papers including 9 wrong p-values for the method used. Simple numerical mistakes were common (19%). An inadequate description of some element of the study was a problem in 22 papers and additional limitations to be described in Discussion were recommended in 26. Numerically most comments were made about some element of the presentation of results.

Discussion: Many of the errors identified are easily avoided. Guidance on some common issues is presented.

Conclusions: Statistical and numerical errors are common in papers submitted to INJURY and requiring statistical review. Following the advice in Discussion and using reporting guidelines should reduce the number of papers requiring corrections.