Data analysis
REGRESSION, PAD, SECONDARY, LEAKAGE
Diagnostic accuracy was the primary outcome. This was assessed by comparing the negative/positive values of the HCST to that of the 24-h pad test to identify the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The secondary outcomes included reliability, association to the 24-h pad test values, and response to change.The reliability of the HCST was assessed by testing the consistency of the HCST results performed 24 h apart. The HCST was analysed by using Cronbach’s alpha between both the positive/negative value of the HCST and the leakage amount questions that were completed 24 h apart. Cronbach’s alpha is an estimation of consistency of items within a measure extending from zero to one. The higher the value, the greater the consistency [A linear regression model was created to explore the relationship of the pad weights and the severity of leakage on HCST (grouped as None, Small, Moderate, and Severe) using an unadjusted model followed by an adjusted model. Adjustments were included for age, body mass index (BMI), parity, pelvic floor management training (PFMT), and previous gynaecological surgery. Subgroup analysis was also performed to consider if the effects change with (a) severity of urgency and (b) diagnosis of MUI.PGI-I responses were analysed using logistic regression to examine response to change. The HCST responses were categorized as: (a) Gets worse, b) No change, c) Small improvement (reduction in leakage at follow-up compared to baseline by one group for example from Moderate to Small on the HCST diagram), or d) Big improvement (reduction in leakage at follow-up compared to baseline by ≥ 2 groups — for example, from Moderate to None on the HCST diagram). The PGI-I responses were grouped as Very much better/Much better as success and all other responses treated as failure This is how the primary outcome was defined in the SIMS trial [Repeated observations were adjusted for using a random effect (intercept) in all necessary models. Analysis was performed using the IBM Corporation Statistical Package for the Social Sciences (SPSS) for Windows version 27 [A post-hoc sample size calculation on the precision of the confidence interval around the estimated sensitivity or specificity was calculated, and with 443 participants, there is 90% power that the maximum width of the confidence interval around the estimated diagnostic accuracy measure is 0.1319.