Diagnostic accuracy of a short-form version of the diagnostic criteria for primary hyperhidrosis

The gold standard method for diagnosing primary hyperhidrosis (PHH) is based on seven patient-reported criteria. By determining an individual criterion's diagnostic accuracy, one can identify short-version classification models. In this cross-sectional study, data were collected from Danish blood donors in 2021. Cohen's kappa and diagnostic accuracy were determined by comparing each criterion with the gold standard method. The study included 1,039 participants. Of them, 59 (5.7%) had PHH and 980 (94.3%) were classified as control individuals. The PHH major criterion "focal visible excessive sweating for at least 6 months without an apparent cause" had the highest prevalence in the participants with PHH compared to the control individuals (100% vs. 0.6%; p < 0.0001). The agreement between this criterion and PHH was Cohen's kappa = 0.95 (95% confidence interval [CI] 0.91-0.99), and its sensitivity was 1.00 (95% CI 0.94-1.00) and specificity 0.99 (95% CI 0.99-1.00). The other criteria showed lower agreement and diagnostic accuracy. The PHH major criterion showed near-perfect agreement and near-equal diagnostic accuracy compared with the gold standard method. This single criterion can be used as a short-form version to screen for PHH. Determination of reproducibility in independent populations is warranted.