Psychometric properties of the 7-item Generalized Anxiety Disorder scale in antepartum women from Ghana and Cote d'Ivoire

Background: To explore the psychometric properties of the 7-item Generalized Anxiety Disorder scale (GAD 7) in West African pregnant women. Methods: In a cross-sectional study, the GAD 7, the PHQ-9 (depression module of the Patient Health Questionnaire) and the WHO-DAS II (12 item World Health Organization Disability Scale) were administered to n=647 Ivorian and n=395 Ghanaian antepartum women with low risk pregnancies (third trimester; gestational age range: 28-40 weeks) in 2010-2011. Statistical analyses combined classical Lest theory (CTT) arid item response theory (IRT). Results: Cronbach's a was close to acceptable (c/=.69 in Me d'Ivoire; a =.67 in Ghana). Consiruct validity was demonstrated by correlations between the GAD -7 and both the PHQ-9 ancl the WHO-DAS ll. Results regarding factorial validity were ambiguous: confirmatory and exploratory factor analyses indicated that the data fit the unidimensionalny assumption; however, the explained variance was low. IRT methods suggested excellent item inkt and outfit. measures. Yet, residual principal component analyses showed a lack of unidimensionaliLy. Basch analyses revealed that the response options were not used as intended. Item-person-fit was not optimal since the items did not discriminate well on the range of the latent construct where most of the women drawn horn the general population were located. Limitations: Both samples were somewhat homogenous regarding gestational age and urban residence; test-retest reliability was not investigated. Conclusion: The GAD-7 met the requirements of CTT. However, applying the stricter criteria of BIT suggested areas for potential improvements. Cross-cultural adaption and a dichotomized response format might ameliorate the GAD-7 for the use in sub-Saharan countries. (C) 2014 Elsevier B.V. All tights reserved.