Translation and cross-cultural adaption of an instrument measuring patient's well-being under treatment for schizophrenia

OBJECTIVES

The Subjective Well-Being under Neuroleptic (SWN) Scale is a self-rating scale measuring the well-being of patients with schizophrenia under antipsychotic drug treatment. The instrument has been globally used, with issues regarding the well-being assessment scale across different cultures, patient characteristics, and country-setting remains a controversy. This study aimed to translate and culturally adapt the SWN scale into the Indonesian version (Indonesian Modified SWN or IM-SWN) and evaluate its validity and reliability.

METHODS

The SWN instrument was translated and culturally adapted following internationally accepted procedures, including forward translation, expert panel review, backward-translation, pretesting and cognitive interviewing, and psychometric analysis for the final version of the scale. The translated instrument was tested on 108 schizophrenia patients. The instrument's validity and reliability were assessed using Pearson's correlation and Cronbach's Alpha coefficient. Additional analysis for the socio-demographic and psychometric properties of the patient was also conducted.

RESULTS

The range of IM-SWN total score between 30 and 112. IM-SWN was found to have a high-reliability coefficient (0.897), and the internal consistency values of each question item ranged between 0.885 and 0.910. The results also showed a high correlation between five order factors (Physical functioning, mental functioning, self-control, emotional regulation, and social integration), with a total score of between 0.768 and 0.885.

CONCLUSIONS

This study highlighted that the IM-SWN is a valid and reliable instrument for measuring well-being among the Indonesian population with schizophrenia.

Refinement of the SWN-20 based on the Rasch rating model

OBJECTIVES

The aim of the present study was to refine the 20-item Subjective Well-Being under Neuroleptic Treatment Scale (SWN-20) using the Rasch rating model to validate measurements of subjective well-being in patients with schizophrenia undergoing antipsychotic treatment.

METHODS

In total, 854 (403 males, 451 females) inpatients (n=213) and outpatients (n=641) with schizophrenia participated in this study, which was designed as an open-label investigation of paliperidone extended release. The participants completed the Korean version of the SWN-20 themselves. Refinement of the Korean version of the SWN-20 was accomplished using the Rasch rating model.

RESULTS

Infit and outfit statistics for all 20 items satisfied the criterion for construct validity. Second, all items except items 2 and 20 had suitable point-measure correlations, reflecting content validity. Third, item characteristic curves indicated that roughly 18 items were evenly distributed along the person ability continuum. Finally, option analysis of the category characteristics showed that categories 3 and 4 in the SWN-20 response format were unnecessary.

CONCLUSIONS

We offer several recommendations for improving the SWN-20: (a) items 2 and 20 should be omitted to ensure construct validity; (b) easier items would be added related to the person ability estimates in the process of validating a short form of the SWN scale based on item response theory; and (c) the number of response categories should be reduced for schizophrenic patients.