Effects of individual and parental educational levels on multimorbidity classes: a register-based longitudinal study in a Danish population

OBJECTIVES: To assess the effects of individual educational level in adulthood and parental educational level during childhood, as well as combinations of individual and parental educational levels, on multimorbidity classes. DESIGN AND SETTING: In this longitudinal study, we used data from a random sample of the Danish population aged 32–56 years without multimorbidity in 2010 (n=102 818). The study population was followed until 2018. Information on individual and parental educational levels and chronic conditions was obtained from national registers. Multinomial logistic regression analyses were adjusted for sex, age and ethnicity. OUTCOME MEASURE: Seven multimorbidity classes were identified using latent class analysis based on 47 chronic conditions. Persons deceased during follow-up comprised a separate class. RESULTS: We found an independent effect of individual educational level on five multimorbidity groups and death, most pronounced for the multimorbidity group ‘Many conditions’ (OR=1.89, 95% CI 1.58 to 2.26 for medium and OR=3.22, 95% CI 2.68 to 3.87 for short compared with long educational level) and of parental education on four groups and death, most pronounced for the multimorbidity group ‘Many conditions’ (OR=1.36, 95% CI 1.07 to 1.73 for medium and OR=1.48, 95% CI 1.15 to 1.89 for short compared with long educational level). Odds of belonging to four multimorbidity classes increased with lower combination of individual and parental educational levels, most pronounced for the multimorbidity group ‘Many conditions’. CONCLUSION: As both individual and parental educational levels contribute to the risk of multimorbidity, it is important to address inequality throughout the life course to mitigate multimorbidity. Future studies could adopt a life course approach to investigate the mediating role of behavioural, clinical, environmental and other social factors.