title: Depression symptoms across cultures: an IRT analysis of standard depression symptoms using data from eight countries.
abstract: Prevalence estimates of depression vary between countries, possibly due to differential functioning of items between settings. This study compared the performance of the widely used Hopkins symptom checklist 15-item depression scale (HSCL-15) across multiple settings using item response theory analyses. Data came from adult populations in the low and middle income countries (LMIC) of Colombia, Indonesia, Kurdistan Iraq, Rwanda, Iraq, Thailand (Burmese refugees), and Uganda (N = 4732).
  
  
  
  Item parameters based on a graded response model were compared across LMIC settings. Differential item functioning (DIF) by setting was evaluated using multiple indicators multiple causes (MIMIC) models.
  
  
  
  Most items performed well across settings except items related to suicidal ideation and "loss of sexual interest or pleasure," which had low discrimination parameters (suicide: a = 0.31 in Thailand to a = 2.49 in Indonesia; sexual interest: a = 0.74 in Rwanda to a = 1.26 in one region of Kurdistan). Most items showed some degree of DIF, but DIF only impacted aggregate scale-level scores in Indonesia.
  
  
  
  Thirteen of the 15 HSCL depression items performed well across diverse settings, with most items showing a strong relationship to the underlying trait of depression. The results support the cross-cultural applicability of most of these depression symptoms across LMIC settings. DIF impacted aggregate depression scores in one setting illustrating a possible source of measurement invariance in prevalence estimates.
authors.affiliation: Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, Baltimore, MD, 21205, USA. eharoz1@jhu.edu.
authors.forename: E E
authors.initials: EE
authors.lastname: Haroz
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA.
authors.forename: P
authors.initials: P
authors.lastname: Bolton
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gross
authors.affiliation: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Chan
authors.affiliation: School of Social Work, Columbia University, 1255 Amsterdam Avenue, New York, NY, 10027, USA.
authors.forename: L
authors.initials: L
authors.lastname: Michalopoulos
authors.affiliation: Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, Baltimore, MD, 21205, USA.
authors.forename: J
authors.initials: J
authors.lastname: Bass
mesh_terms: D000328:Adult; D003105:Colombia / Q000453:epidemiology; D003431:Cross-Cultural Comparison; D003863:Depression / Q000453:epidemiology* / Q000208:ethnology; D003906:Developing Countries / Q000706:statistics & numerical data*; D005006:Ethnicity / Q000523:psychology / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007214:Indonesia / Q000453:epidemiology; D007493:Iraq / Q000453:epidemiology; D008297:Male; D008962:Models, Theoretical; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012432:Rwanda / Q000453:epidemiology; D013785:Thailand / Q000453:epidemiology; D014454:Uganda / Q000453:epidemiology
keywords: Depression; Global mental health; Item response theory; Measurement invariance; Psychometrics