Confirmatory factor analysis and factorial invariance analysis of the adolescent self‐report Strengths and Difficulties Questionnaire: How important are method effects and minor factors?

Abstract

OBJECTIVES. This study examined the factor structure of the self-report Strengths and Difficulties Questionnaire, paying special attention to the number of factors and to negative effects of reverse-worded items and minor factors within the subscales on model fit. Furthermore, factorial invariance across gender, age, level of education, and ethnicity was investigated. DESIGN. Data were obtained from the Youth Health Monitor Rotterdam, a community-based health surveillance system. METHODS. The sample consisted of 11,881 pupils of 11-16 years old. Next to the original five-factor model, a factor model with the number of factors based on parallel analysis and scree test was investigated. Confirmatory factor analysis for ordered-categorical measures was applied to examine the goodness-of-fit and factorial invariance of the factor models. RESULTS. After allowing reverse-worded items to cross-load on the prosocial behaviour factor and adding error correlations, a good fit to the data was found for the original five-factor model (emotional symptoms, conduct problems, hyperactivity-inattention, peer problems, prosocial behaviour) and a model with four factors (emotional symptoms and peer problems, conduct problems, hyperactivity-inattention, prosocial behaviour). Factorial invariance across gender, age, level of education, and ethnicity was found for the final five- and four-factor model, except for the prosocial factor of the four-factor model that showed partial invariance across gender. Conclusions. While support was found for both models, the final five-factor model is theoretically more plausible and gained additional support as the original scales emotional problems and peer problems showed different relations with gender, educational level, and ethnicity.

New evidence of factor structure and measurement invariance of the SDQ across five European nations

“…Moreover, some goodness-of-fit indices of Ireland were still not appropriate. Similar results were found in previous studies [40,32,19,26]. For instance, the study of Ortuño-Sierra et al [40] showed that the five-factor structure was the better to fit the data, but appropriate goodness-of-fit were only reached after correlated errors were added.…”

“…Thus, the five-factor structure is still questionable. In the same line, a modified five factor model allowing the reverse-worded items to cross-load on the Prosocial factor displayed significant better goodness-of-fit indices in all the countries, including the total sample, as it was the case in the study of van de Looij-Jansen et al [26]. However, the study of factor loadings revealed that some of them were non-significant, questioning the adequacy of this model.…”

“…Nevertheless, several studies have detected low values of reliability (Cronbachs's alpha ˂ .60), especially in the Conduct problems and Peer problems subscales [16][17][18][19][20][21][22][23]11,24,25]. An added value of the test, as it the fact that it contains positive items, could be a key factor in explaining low internal consistency and the inconsistency of factorial solutions [26]. The fact that the problems subscales includes this type of items can generate that they behave as part of a distinct construct [20].…”

“…Therefore, reverse-worded items may influence the estimation of internal consistency due to their low correlation with the rest of the SDQ items that measure problems, and could, at the same time, affect the factor structure [26]. In this sense, a fivefactor solution of the SDQ with the same 25 items but allowing the reverse-worded items to cross-load on the Prosocial subscale has been proposed as the most satisfactory [26].…”

“…Previous studies have analyzed the MI of the SDQ, self-reported version in adolescents, across different variables (e.g., gender, age, race/ethnicity, and income) [19,11,26,[38][39][40]. As yet, there has been no in-depth examination addressing the question of whether the dimensional structure underlying the SDQ scores is invariant across countries.…”