[Methodology and quality control in EPIGRAM, a pharmacoepidemiological study of obesity in general practice]

The EPIGRAM pharmacoepidemiological study was conducted in general practitioners prescribing orlistat (Xenical) in order to describe, under real clinical conditions, the management of obese or overweight patients. A 1-year follow-up of a patient cohort treated with orlistat was also conducted. Quality criteria specific to the study were defined to ensure the scientific validity of the results; these criteria mainly involved the following items: independent scientific committee, sampling investigator's recruitment, study organisation and quality control of the collected data. On-site control visits of a sample of 13% of participating GPs revealed that 75% of the controlled data were documented in a source file of which 85% were consistent with the source data. Only 1% of the 130 000 controlled data (data were controlled only on visits for which information was available) gave rise to correction requests. Of the patients treated with orlistat on inclusion, 17% were lost to follow-up by their GP and 25% were contacted directly at the end of the study.