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

TY - JOUR

T1 - Psychometric properties of the 7-item Generalized Anxiety Disorder scale in antepartum women from Ghana and Côte d'Ivoire

AU - Barthel, Dana

AU - Barkmann, Claus

AU - Ehrhardt, Stephan

AU - Bindt, Carola

AU - International CDS Study Group

N1 - Copyright © 2014 Elsevier B.V. All rights reserved.

PY - 2014/12/1

Y1 - 2014/12/1

N2 - 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 test theory (CTT) and item response theory (IRT).RESULTS: Cronbach׳s α was close to acceptable (α=.69 in Côte d'Ivoire; α=.67 in Ghana). Construct validity was demonstrated by correlations between the GAD-7 and both the PHQ-9 and the WHO-DAS II. Results regarding factorial validity were ambiguous: confirmatory and exploratory factor analyses indicated that the data fit the unidimensionality assumption; however, the explained variance was low. IRT methods suggested excellent item infit and outfit measures. Yet, residual principal component analyses showed a lack of unidimensionality. Rasch 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 from 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 IRT 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.

AB - 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 test theory (CTT) and item response theory (IRT).RESULTS: Cronbach׳s α was close to acceptable (α=.69 in Côte d'Ivoire; α=.67 in Ghana). Construct validity was demonstrated by correlations between the GAD-7 and both the PHQ-9 and the WHO-DAS II. Results regarding factorial validity were ambiguous: confirmatory and exploratory factor analyses indicated that the data fit the unidimensionality assumption; however, the explained variance was low. IRT methods suggested excellent item infit and outfit measures. Yet, residual principal component analyses showed a lack of unidimensionality. Rasch 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 from 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 IRT 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.

U2 - 10.1016/j.jad.2014.08.004

DO - 10.1016/j.jad.2014.08.004

M3 - SCORING: Journal article

C2 - 25212996

VL - 169

SP - 203

EP - 211

JO - J AFFECT DISORDERS

JF - J AFFECT DISORDERS

SN - 0165-0327

ER -