One size does not fit all: Psychometric properties of the ShonaSymptom Questionnaire (SSQ) and symptomology among adolescents and young adultsin Zimbabwe

摘要

Poor mental health among is a major contributor to the burden of disease among adolescents. For this paper we use cross sectional survey data among a sample of 2,768 adolescent (aged 15-19) and 2,027 young adults (aged 20-24) living in Manicaland Province, Zimbabwe to calibrate the Shona Symptom Questionnaire (SSQ) against the Self Report Questionnaire (SRQ-20) and examined the performance indices of the SSQ based on various cut points for classification. The SSQ depression screening tool performed best with a cut point of five or more positive responses out of 14 questions, resulting in the following validation coefficients for adolescents and young adults respectively: AUC (0.83, 088); kappa statistic (0.64, 0.66); sensitivity (0.89, 0.95); specificity (0.94, 0.92); PPV (0.45, 0.55); NVP (0.99, 1.00). The modified SSQ cut point of five or more substantially increase the depression estimates for both age groups to align more closely with the SRQ-20 estimates. The prevalence of depression increased from 3.5% to 13.2% among adolescents and from 5.1% to 16.2% among young adults based on these revisions to the SSQ. Using a multivariate logistic regression model we isolated particular characteristics to test their association with the odds of being misclassified as non-depressedbased on the conventional SSQ cut point. Findings suggest that adolescents whowere orphaned (OR 1.48) or ever had sex (2.13) were at a significantly greaterodds of being a false negative than their counterparts. Secondary education wassignificantly associated with false negative misclassification among youngadults (OR 2.11). When retested using the modified cut point of five or greater,associations with misclassification disappeared. This study highlight that notall depression scales are appropriate for use among adolescents given theirunique developmental stage. While using culturally-appropriate scales such asthe SSQ is important, we strongly recommend modification to the cut point inorder to improve adolescent depression detection. Alternatively we recommendcontinued use of the standardized cross-cultural SRQ given it continued successat classify cases of depression across age groups.