Psychometric properties of the Tamil version of Perceived Stress Scale among diabetes mellitus patients in Puducherry, South India

INTRODUCTION: Perceived Stress Scale (PSS), developed in 1983, is one among the widely used global scales to assess the perceived psychological stress status. Hence, our study aimed at developing a Tamil version of THE 10-item PSS (TPSS-10) and assess its construct validity and internal consistency among patients with diabetes in Puducherry, South India. METHODS: We translated the TPSS-10 by language experts and pilot-tested the sample with a subsample of diabetes patients. The finalized version of TPSS-10 was administered to 117 Tamil-speaking diabetic patients availing services from the rural health center in Puducherry, South India. Construct validity was assessed using the exploratory factor analysis (EFA) and the principal component analysis (PCA). A confirmatory factor analysis (CFA) was also done to obtain the goodness-of-fit. Reliability of questionnaire was evaluated by Cronbach’s alpha. RESULTS: Two factors were obtained with Eigenvalues of 4.61 and 2.16. Both factors explained 67.8% of the total variance. The two-factor model assessed by CFA found a χ(2) value of 714.99 (P < 0.001). Goodness-of-fit revealed acceptable comparative fit indices (0.93). The reliability coefficient (Cronbach’s alpha) for complete TPSS-10 was 0.86, indicating good internal consistency. DISCUSSION: Our study concludes that the TPSS-10 questionnaire is internally valid and consistent with good reliability coefficient after its administration to Tamil-speaking urban diabetic patients in order to measure perceived stress. However, further research is warranted to content-validate the tool with a standard diagnostic instrument.