EQ-5D-5L Bulgarian population norms

Abstract

Objectives: The present study aimed to provide normative data for the EQ-5D-5L questionnaire in Bulgaria, based on a nationally representative sample.

Methods: Random sampling was used. In September 2018, a total of 1005 respondents (aged 18-89 years) completed the self-administered paper-based EQ-5D-5L questionnaire, including a visual analogue scale (EQ VAS). Health state utility index scores were derived using the directly measured Polish value set.

Results: The study sample was representative of the general Bulgarian population in terms of age, sex, geographical region, educational level, social and professional status. Mean EQ-5D-5L and EQ VAS values decreased from 0.986 and 89.7 (age group 18-24 years) to 0.789 and 53.6 (age group ≥ 75 years), respectively. Perfect health (the "11,111" health state) was reported by half of the population (50.1%), more often by men than women (55.8% vs 44.9%). The most frequently reported complaints characterised pain/discomfort dimension (39.1%), followed by anxiety/depression (34.5%). Although the least commonly reported health limitations concerned the self-care dimension, their frequency (13.6%) was the highest among the seventeen identified EQ-5D-5L population norm studies. The mean severity index score for the whole study sample was 6.96. EQ-5D-5L index was higher in respondents from lower age groups and with a higher average income per household member.

Conclusions: Bulgarian population norms, which were developed for the descriptive part of the EQ-5D-5L and EQ VAS, can be used as reference values. The availability of such normative data should encourage the use of the EQ-5D-5L questionnaire in health-related quality-of-life studies in Bulgaria.

Keywords: CEE; EQ VAS; EQ-5D-5L index values; Health state utilities; Health-related quality of life; Population norms.