Socioeconomic inequalities in the prevalence of multimorbidity in Portugal: results from the fifth National Health Interview Survey 2014

Patients with multimorbidity have poor health outcomes, high healthcare utilisation, and increased average cost of care. In Portugal, in a context of severe aging, this becomes a major public health concern. This study aims to estimate the prevalence of multimorbidity and quantify the socioeconomic inequalities in the occurrence of multimorbidity in Portuguese population aged 35 years or over. Data from the National Health Interview Survey (n=14943) held in 2014 were analyzed. Multimorbidity was defined as self-report of two or more chronic conditions. Participants' socioeconomic position was measured through education and household equivalized disposable income. The relative index of inequality (RII) were estimated to determine the socioeconomic inequalities, controlling for age, occupation, degree of urbanization and cohabitation. All estimates were weighted to account for complex sample design and stratified by sex. The prevalence of multimorbidity in Portuguese population aged 35 years or over, was 42.5% [95%CI: 40.6-44.5] and 60.4% [95%CI: 58.58-62.15] for men and women, respectively. We observed an inverse educational gradient in multimorbidity for both men (RII=1.34, [95%CI:1.12-1.60] and women (RII=1.45, [95%CI:1.30-1.62]). Income-related inequalities were smaller (RII=1.25, [95%CI: 1.08-1.45] for men, and not significant for women (RII=1.02, [95%CI:0.94-1.1]). In addition to be highly prevalent, multimorbidity is unequally distributed in the Portuguese population, being more frequent amongst the less educated men and women, and amongst the poorer men. Future public health policies and interventions should take in considerations this socioeconomic patterning.N/