The results of one other study revealed an association between higher scores on intolerance of clinical uncertainty and higher scores on reliance on high-technology medicine in medical students and a preference for ‘medicine by numbers.’24 Applying this explanation to the present findings, GPs who were intolerant of ambiguity may perceive the PSA test as a way to quantify the risk of prostate cancer in worried patients. This evidence concerns the gene KLK3 and prostate cancer.