Validation of the WeDQoL-Goals Thailand Measure: culture-specific individualised quality of life

The aim of this study was to validate an individualised measure of quality of life (WeDQoL-Goals-Thailand). Three hundred and sixty-nine Thai people completed the WeDQoL by interview. Respondents rated (0-2) the perceived necessity for wellbeing of 51 goals (goal necessity), then rated (0-3) their satisfaction with the same goals (goal satisfaction). Weighted goal attainment (possible range 0-6) was computed (necessity x satisfaction). Psychometric validation used frequency distributions, Principal Components Analysis (PCA), and Cronbach’s alpha. Analysis of variance, t-tests, Kruskal-Wallis, Mann-Whitney U, Spearman’s correlation and multiple regression explored socio-demographic, geographic and economic differences. Respondents were aged 15-89 (mean 45.7, SD 18.0); 169 men, 200 women. For weighted goal attainment scores, PCA found a 44-item scale (α = 0.91) and three subscales (community/social/health, α = 0.90; house and home, α = 0.80; nuclear family, α = 0.81). Thai Individualised Goal Attainment (TIGA) scale and the three subscales were computed as the mean of contributing weighted goal attainment scores, after excluding goals considered ‘not necessary’ to each individual. Unweighted and individualised scores differed significantly with socio-demographic, geographic and economic indicators. In multiple regression, both Thai Unweighted Goal Satisfaction (TUGS) and TIGA scale scores were predicted by being married, living in the South and in a non-urban location. TIGA scores were also predicted by being over 25 years old. WeDQoL-Goals-Thailand has excellent psychometric properties. Individualised scores reflect each person’s perspective on wellbeing and are sensitive to subgroup differences. However, unweighted satisfaction scores give a broadly similar picture and involve less complex computation.