The reading, writing, and arithmetic of the medical literature, part 2: critical evaluation of statistical reporting.

OBJECTIVE: To offer suggestions to help improve clinicians' understanding of the statistical analyses in the literature and their use of these methods in their own medical writings. DATA SOURCES: Literature searches began at the National Library of Medicine's online database and were traced to primary sources. STUDY SELECTION: All referenced information in this article was cited from primary sources.
RESULTS: Physicians should be able to determine the variables studied and how they were measured, the comparisons that were made, the difference (with 95% confidence interval) between the groups, the exact P value for the difference, the statistical test used in the analysis, whether the data conformed to the assumptions of the test, whether the study had adequate statistical power, and the clinical importance of the difference.
CONCLUSION: Clinicians should know how to interpret statistical results so that they can use medical science to its full extent in treating patients.