Changes over time in social inequality in adult self-rated health: the case of Norway 2002–2019

Findings on how social inequality in self-rated health (SRH) has changed over time are not uniform. To inform public health policies aimed at reducing unwarranted social differences in health, we examine time trends in relative and absolute associations between SRH and three different socioeconomic measures using Norway as a case. Six rounds (2002–2019) of repeated national, cross-sectional, data from Statistics Norway’s Survey on Living Conditions (response rates 57–70%) were linked to register information on socioeconomic measures (education, household income and occupation). A set of logistic regression models of good SRH (GSRH) with blockwise inclusion of predictors were employed to 29,012 adults (25–66 years). Absolute and relative differences in GSRH across education, income and occupation were calculated across survey years, net of other sociodemographic characteristics and risk factors. Regardless of model, the probability of reporting GSRH was high (around 80%) across sex for most years. Considering only statistically significant results, men with the short education had a 2-4% points lower probability of GSRH than men with long education, across years. The time trend in income differences was also stable, albeit the difference between the highest and lowest quintile was larger (around 7% points). Those outside the labor force were substantially less likely (23% points) to report GSRH compared to men in high skilled white-collar occupations. Among women, GSRH was 6% points lower among those with short compared to long education, and 8% points lower in the 1st compared to the 5th income quintile. Being outside the labour force was associated with a 28% points lower probability of GSRH among women. Otherwise, there were minor differences in GSRH between occupational groups. On a relative scale (percent difference), differences between socioeconomic groups were slightly more pronounced, but with similar trends for men and women. Irrespective of socioeconomic measure, social inequalities in SRH have remained remarkably stable over time across socioeconomic measures in Norway, in both absolute and relative terms. The national strategy may have worked to prevent increasing social inequalities in health, but system changes and further actions appear warranted to reduce existing differences.