Sas v9

Sensitivity and specificity for Groups 1 and 2 assignment were computed using the ETDQ-7 score of ≥ 14.5^{16 (link)} and PEq₅<60% as an indication of ETD. The ETDQ-7 does not discriminate if symptoms come from left, right or both ears, so to avoid assumptions that could create a selection bias, the primary PEq₅ statistical analysis was done at participant level using the lowest PEq₅ for two ears, and at ear level using the same ETDQ-7 for both ears.
For participant level analysis, ETDQ-7 and PEq₅ scores were compared between symptomatic and control groups using two-sample Wilcoxon test (proc npar1way, SAS v.9.4, Cary, NC). Exact 95% Clopper-Pearson confidence intervals (CI) were obtained for sensitivity and specificity (proc freq, SAS, v. 9.4) and Fisher exact test was used for comparing sensitivity or specificity between different subgroups of patients.
Kendall’s correlation coefficient was used to test association between the PEq₅ and ETDQ-7 scores (proc corr, SAS, v.9.4). Association of ETDQ-7 scores with the inadequate PEq₅<60% as well as with group assignment were assessed using empirical Area under the ROC curves (AUC).^{23 (link),24} At ear-level data, statistical analysis (including evaluating Kendall’s coefficient and AUC) was performed using non-parametric bootstrap CI for clustered data with participant as a resampling unit, based on 10,000 bootstrap samples.²⁵