Preliminary study of the Thai-version of the Scale for the Assessment of Positive Symptoms (SAPS-Thai): content validity, known-group validity, and internal consistency reliability

Thammanard Charernboon

doi:10.1590/0101-60830000000183

Abstract

Abstract Objective To assess the psychometric properties of the Thai version of the Scale for the Assessment of Positive Symptoms (SAPS-Thai). Methods Content validity was evaluated by four psychiatrists who rated the SAPS-Thai, and the content validity indexes (CVI) were also analyzed. Known-group validity was assessed by comparing the SAPS-Thai score among thirty outpatients and ten inpatients with schizophrenia. Internal consistency was calculated using the Cronbach’s coefficient alpha. Results SAPS-Thai has excellent content validity, with an average-CVI of 0.92. The inpatient group had a significant higher score for both the global SAPS-Thai scores [7.4 (1.95) vs. 1.93 (1.59), p < 0.001] and total SAPS-Thai scores [21.2 (11.8) vs. 3.67 (2.87), p < 0.001] indicating good known-group validity. SAPS-Thai had a good internal consistency with a Cronbach’s alpha of 0.87. Discussion SAPS-Thai provides a comprehensive measurement of positive symptoms and indicated content and known-group validity and a satisfactory level of internal consistency reliability.

Highlights

Schizophrenia is a complex chronic disease that causes impairment to occupational and social functions
A few items were added to the Chinese version of Scale for the Assessment of Positive Symptoms (SAPS), while several symptom definitions were changed during the translation process
The study was comprised of two parts: the first part was the development of the Thai-SAPS and an examination of the content validity, while the second part was the assessment of its internal consistency and known-group validity

Summary

Introduction

Schizophrenia is a complex chronic disease that causes impairment to occupational and social functions. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) describes four characteristics of positive symptoms, namely, delusions, hallucinations, disorganized speech, and disorganized behavior[1]. For both clinical and research purposes, it is essential to have a standard, validated, and reliable assessment of the symptoms. The Chinese version demonstrated good internal consistency (0.84) and an excellent inter-rater reliability (0.95) for the overall score. It strongly correlated with the Brief Psychiatric Rating Scale[3]

Methods

Results

Conclusion