Data analysis
SENSITIVITY
Pearson’s chi-square was used for dichotomous variables and t-test for continuous variables to analyze potential differences with respect to background factors between genders among participants, between participants and the general population of women and men 25–44 years of age and between respondents and non-responders. Given the use of baseline data, responses from all parents were analysed without regard to randomization status. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each targeted problem in the PSQ-S with the corresponding standardized instruments as the reference test. The data in both the PSQ-S and the validated instruments were dichotomized before analysis. Differences in proportions of positive screens between genders and between the PSQ-S and the standardized instruments were analyzed using Pearson’s chi-square, as were differences between genders regarding sensitivity, specificity, NPV and PPV. Internal consistency was analyzed using Cronbach’s α. Exploratory factor analysis applying varimax rotation and a minimum Eigen value of 1.0 was used to evaluate the factor structure of the 14 items of the PSQ-S after excluding questions regarding child safety issues. Factor loading values above 0.3 were considered salient enough to be practically meaningful. The analyses were carried out using SPSS Statistics 28.0 (IBM SPSS Statistics for Macintosh, Version 28.0).