This study aimed to analyze the possible resemblance or difference in outcome in a case-control study of quality of life for IBS patients compared to controls free from the disease, when a matching procedure for age and sex was applied for the control group compared to when all participating subjects were included in the control group. The main result was that almost the same and identical results were found irrespective of whether matching or not matching was applied in this epidemiological case-control study. The matching procedure however, slightly diminished the statistical power of the results.
Keywords: case-control study; epidemiology; gender; matching.