Confirmatory factor analysis of the causal illness attribution scale in Chinese patients with multiple somatic symptoms

Abstract

Causal illness attributions influence how individuals cope with somatic symptoms and illnesses. Dimensions of causal symptom attributions have been examined in Western cultures with the subscale ‘causes’ of the revised Illness Perception Questionnaire (IPQ-R). Some previous studies have identified a stronger somatic attribution style in Asian patients. In this study it was examined if the factorial structure of causal attributions identified in Western populations can be identified in a large Chinese sample of patients presenting with somatic symptoms. We recruited 665 patients aged at least 18 who were visiting the hospital for reasons of treatment from departments of traditional Chinese medicine (TCM), neurology (Biomedicine), and psychosomatic medicine in six hospitals across China. All subjects completed the Patient Health Questionnaire (PHQ) and the causes subscale of the IPQ-R. We split the data-set by chance in two parts. On the first subsample, we conducted a confirmatory factor analysis (CFA) to check the fit of the originally proposed 4-factor structure and an exploratory factor analysis (EFA). The factor structure indentified in the EFA was rechecked with a CFA in the second subsample. The originally proposed 4-factor-model of the IPQ-R subscale causes showed no adequate fit in the first subsample. The EFA revealed two factors, psychological attributions and risk factors. The CFA in the second sample showed mediocre fit indices (RMSEA = .098, CFI = .923). For the Chinese sample we propose a two-factor structure for IPQ-R causes scale. As in other studies, we identified the relatively stable factor psychological attributions, indicating no fundamental differences in illness attributions between Western and Chinese samples.