General Health Questionnaire-12 reliability, factor structure, and external validity among older adults in India

AIMS: The purpose of this study is to analyze the internal consistency, factor structure, and external validity of the 12-item General Health Questionnaire (GHQ-12) among older adults in India. SETTINGS AND DESIGN: This study analyzes data collected as part of the UNFPA “Building Knowledge Base on Ageing in India (BKPAI)” project. The BKPAI Survey was conducted in 2011 in seven major demographically advanced states of India – Himachal Pradesh, Punjab, West Bengal, Odisha, Maharashtra, Kerala, and Tamil Nadu. MATERIALS AND METHODS: A community-based representative sample of 9692 respondents aged 60 and above from seven Indian states was employed. The GHQ-12 questionnaire was administered. STATISTICAL ANALYSIS: The Cronbach's alpha was calculated to analyze internal consistency. Factor analysis was applied to explore the factor structure of GHQ-12, and then correlation coefficients were calculated to examine the external validity of the measurement. RESULTS: The Cronbach's alpha of the GHQ-12 is 0.9. Factor analysis reveals two significant components which accounted for 59% of the variance. The correlation between the overall score of GHQ-12 and the subjective well-being inventory (SUBI) is 0.58. CONCLUSIONS: The GHQ-12 shows adequate reliability among the older population in India.