ObjectiveTo identify factors associated with health literacy in multimorbid patients.DesignA nationwide cross-sectional study in Switzerland. Univariate and multivariate linear regressions were calculated to identify variables associated with health literacy. A multiple imputation approach was used to deal with missing values.ParticipantsMultimorbid patients recruited in primary care settings (n=888), above 18 years old and suffering from at least 3 of 75 chronic conditions on a predefined list based on the International Classification of Primary Care 2.Main measuresHealth literacy was assessed using the European Health Literacy Survey project questionnaire (HLS-EU 6). This comprises six items scored from 1 to 4 (very difficult=1, fairly difficult=2, fairly easy=3, very easy=4), and the total health literacy score is computed as their mean. As we wished to understand the determinants associated with lower health literacy, the HLS-EU 6 score was the only dependent variable; all other covariates were considered independent.ResultsThe mean health literacy score (SD) was 2.9 (0.5). Multivariate analyses found significant associations between low health literacy scores and treatment burden scores (β=−0.004, 95% CI −0.006 to 0.002); marital status, predominantly the divorced group (β=0.136, 95% CI 0.012 to 0.260); dimensions of the EuroQuol 5 Dimension 3 Level (EQ5D3L) quality of life assessment, that is, for moderate problems with mobility (β=−0.086, 95% CI −0.157 to 0.016); and with moderate problems (β=−0.129, 95% CI −0.198 to 0.060) and severe problems with anxiety/depression (β=−0.343, 95% CI −0.500 to 0.186).ConclusionsMultimorbid patients with a high treatment burden, altered quality of life by problems with mobility, anxiety or depression, often also have low levels of health literacy. Primary care practitioners should therefore pay particular attention to these patients in their daily practice.