AN ANALYSIS OF RANDOMIZED CONTROLLED TRIALS PUBLISHED IN THE US FAMILY MEDICINE LITERATURE, 1987-1991

Background. Randomized controlled trials (RCTs) are frequently used to evaluate the effectiveness of health care interventions in family med icine. The value of the information obtained from RCTs depends largely on the quality of design and the way in which they are conducted and reported. Despite the increasing number of RCTs being conducted in fam ily medicine, there is a scarcity of descriptive data on the methodolo gical characteristics, including design features and quality of RCTs i n this setting. Methods. All 53 RCTs published in four peer-reviewed U S family medicine journals between 1987 and 1991 were identified and t heir methodological characteristics reviewed. Three potential sources of bias were assessed in each of the trial reports: (1) control of sel ection bias at entry, (2) control of selection bias after entry, and ( 3) control of bias in assessing outcome(s). Results. Fifty-five RCTs p ublished between January 1987 and December 1991 were identified in the four journals. The absolute number of RCTs published over the 5 years increased steadily, and there was a 49% increase in the proportion of RCT articles. Measures used to control for selection bias before entr y into the study were reported in 14 (25%) of the RCTs, the statistica l power of the trial in 5 (3%), and whether the study had been reviewe d by an institutional review board in 6 (11%). Conclusions, The RCTs a nalyzed offered some imaginative solutions to the logistic difficultie s of conducting RCTs in general practice. Nevertheless, the methodolog y and reporting of RCTs in the future should be improved.