Statistical and research quality of the medical and pharmacy literature.

The statistical and research quality of reports published in two U.S. medical journals and two U.S. pharmacy journals over a 12-month period was determined. A 50% random sample of issues of New England Journal of Medicine, Annals of Internal Medicine, American Journal of Hospital Pharmacy, and Drug Intelligence and Clinical Pharmacy published in 1979 was reviewed, and all citable items were classified as one of nine types of communications. Items classified as original evaluative research reports were evaluated for experimental design and research goals and rated for appropriateness of statistical testing and overall research quality according to a set of objective criteria. Reports that were not immediately classifiable were reviewed by one additional person, and classifications or ratings were assigned by mutual consent. Of a total of 1506 citable items, 120 met the criteria for original evaluative research reports. The two medical journals had the highest percentages of reports for which statistical methods were rated as correct but also had the most reports for which statistical methods could not be rated as a result of incomplete documentation or publication errors. Reports in the medical journals had conclusions based on a logical progression of hypothesis, methods, and analysis of results more frequently than did reports in pharmacy journals. Reports in the medical and pharmacy journals differed greatly according to research design and research goals. Improvement is needed in the statistical quality and research quality of original research reports published in the pharmacy literature.