Which aspects of subjectively reported quality of life are important in predicting mortality beyond known risk factors? The Lothian Birth Cohort 1921 Study

To investigate which aspects of Quality of Life (QoL) (physical health, psychological, social-relationships, and environment) are important in predicting mortality. A sample of 448 (194 men and 254 women) relatively healthy older adults reported their QoL using the WHOQOL-BREF. After a 9-year follow-up, survival analysis was carried out using Cox's proportional hazards regression. Only the General Health item (HR = 0.75, 95% CI: 0.64-0.89) and Physical Health Domain mean score (HR = 0.90, 95% CI: 86-0.95) significantly predicted mortality when controlling for age and sex. The single-item General Health measure was the stronger predictor of mortality and remained significant after socio-demographic, psychological (personality and cognition), health behaviour and health status measures were controlled for independently. When all measures were simultaneously controlled for, none of the items or domains on the WHOQOL-BREF significantly predicted mortality. Items addressing health-related QoL are the most important when predicting mortality. The findings support research demonstrating that subjectively rated, single-item general health questions accurately predict survival over and above socio-demographic, psychological, health behaviour and health status measures.