Interpreting the WHOQOL-Bref: Preliminary population norms and effect sizes

Since publication use of the WHOQOL-Bref has rapidly risen. However, as yet no population norms have been published as a reference point against which researchers can interpret their findings. This study provides preliminary population norms for this purpose. Randomly sampled community residents from two studies were pooled and used to examine the properties of the WHOQOL-Bref by age group, gender and health status. The results showed that general norms for the WHOQOL-Bref domains were 73.5 (SD=18.1) for the Physical health domain, 70.6 (14.0) for Psychological wellbeing, 71.5 (18.2) for Social relationships and 75.1 (13.0) for the Environment domain. In general scores declined slightly by age group. For females scores were stable across the lifespan with an accelerated decline after the age of 60 years. Males exhibited a more consistent and even decline across the lifespan. There were significant differences in WHOQOL-Bref scores when reported by health status, with those in poor health obtaining scores that were up to 50% lower than those in excellent health. Effect sizes between different health status levels are reported. These preliminary norms and effect sizes may be used as reference points for interpreting WHOQOL-Bref scores. They provide additional information to the numerous national studies already reporting on the validity of the WHOQOL-Bref.