Jan van Amsterdam1, Florence Vorspan2, Marieke B Snijder3, Wim van den Brink1, Aart H Schene4, Karien Stronks3, Henrike Galenkamp3, Eske M Derks5. 1. Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. 2. Assistance Publique - Hôpitaux de Paris, Fernand Widal Hospital, Department of Psychiatry and Addiction Medicine, Paris, France; INSERM UMR-S1144, Paris, France. 3. Department of Public Health, Amsterdam Public Health (APH) research institute, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. 4. Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands; Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands. 5. Translational Neurogenomics group, QIMR Berghofer, Brisbane, Australia. Electronic address: eske.derks@qimrberghofer.edu.au.
Abstract
BACKGROUND: The prevalence of smoking varies across ethnic groups in developed countries, but little is known about ethnic variations in specific aspects of nicotine dependence (ND). We conducted item-response analyses in current smokers to compare ND factors across five ethnic groups. METHODS: Data were obtained from a population-based, multi-ethnic cohort study conducted in the Netherlands. The Fagerström Test for Nicotine Dependence (FTND) was assessed in 1147 Dutch, 991 South-Asian Surinamese, 1408 African Surinamese, 1396 Turkish, and 584 Moroccan smokers (N = 5526). We tested whether the factorial structure of the FTND was invariant across ethnic groups using a multi-group confirmatory factor analysis. FTND item and total scores and factor means were compared across groups. RESULTS: The two-factor model representing "morning smoking" and "smoking patterns" provided an adequate fit. The items "Cigarettes smoked daily" and "Time until first cigarette" showed differential item functioning (DIF) as a function of ethnicity. Three out of four ethnic minority groups scored significantly higher on both factors compared to the Dutch origin group (all p < 0.001) before and after taking DIF into account, while the African Surinamese scored higher only on "morning smoking" when DIF was accounted for. DISCUSSION: The factor structure of the FTND is not measurement invariant across ethnic groups in this population-based sample. Accounting for DIF affecting the nicotine dependence factor scores, although South-Asian Surinamese, Turkish, and Moroccan groups showed higher levels of dependence than the Dutch origin group, genetic as well as environmental factors may account for the observed differences.
BACKGROUND: The prevalence of smoking varies across ethnic groups in developed countries, but little is known about ethnic variations in specific aspects of nicotine dependence (ND). We conducted item-response analyses in current smokers to compare ND factors across five ethnic groups. METHODS: Data were obtained from a population-based, multi-ethnic cohort study conducted in the Netherlands. The Fagerström Test for Nicotine Dependence (FTND) was assessed in 1147 Dutch, 991 South-Asian Surinamese, 1408 African Surinamese, 1396 Turkish, and 584 Moroccan smokers (N = 5526). We tested whether the factorial structure of the FTND was invariant across ethnic groups using a multi-group confirmatory factor analysis. FTND item and total scores and factor means were compared across groups. RESULTS: The two-factor model representing "morning smoking" and "smoking patterns" provided an adequate fit. The items "Cigarettes smoked daily" and "Time until first cigarette" showed differential item functioning (DIF) as a function of ethnicity. Three out of four ethnic minority groups scored significantly higher on both factors compared to the Dutch origin group (all p < 0.001) before and after taking DIF into account, while the African Surinamese scored higher only on "morning smoking" when DIF was accounted for. DISCUSSION: The factor structure of the FTND is not measurement invariant across ethnic groups in this population-based sample. Accounting for DIF affecting the nicotine dependence factor scores, although South-Asian Surinamese, Turkish, and Moroccan groups showed higher levels of dependence than the Dutch origin group, genetic as well as environmental factors may account for the observed differences.