Development and psychometric evaluation of the occupational adaptation scale for individuals with schizophrenia

The aim of this study was to test the reliability and validity of OAS-S to measure occupational adaptation in schizophrenia.

We used the Davis technique with 10 expert panellists and administered the scale form to 320 people. Two weeks later, we tested 80 people again. Then, we conducted item analysis to evaluate the internal consistency. We also conducted exploratory and confirmatory factor analysis to examine the structural validity.

The content validity index of the scale was found to be 0.895. Exploratory factor analysis showed that the scale consisting of 18 items had a three-factor structure that explained 69.925% of the variance. The model fit indices showed that the measurement model was appropriate (RMSEA = 0.045; GFI = 0.954; AGFI = 0.885; NNFI = 0.935; CFI = 0.946; NFI = 0.964; IFI = 0.973; CMIN/DF = 2.405). The results of the reliability analysis were as follows: Intraclass Correlation Coefficient = 0.995 and Cronbach's alpha = 0.998. The results showed very high and statistically significant correlation coefficients between the first and second administrations (r = 0.992; p < 0.001).

The OAS-S is a valid and reliable scale consisting of 18 items and 3 subscales. It consists of person, interaction, and occupational environment subdomains. We recommend further studies to validate the scale and adapt it across cultures.