BackgroundOne can assume a relatively high prevalence of urinary incontinence (UI) in people with multimorbidity. However, literature in this area is scarce. There is a need for further robust research to aid GPs to identify patients at a particular risk for UI, and to initiate the early treatment and multidisciplinary management of this condition.AimTo examine the association between multimorbidity and UI in 23 089 individuals aged ≥15 years and residing in Spain.Design and settingThis study used data from the Spanish National Health Survey 2017, a cross-sectional sample of 23 089 participants aged ≥15 years residing in Spain (54.1% female; mean [standard deviation] age = 53.4 [18.9] years).MethodUI and 30 other physical and mental chronic conditions were self-reported. Multimorbidity was defined as the presence of ≥2 physical and/or mental chronic conditions (excluding UI). Control variables included sex, age, marital status, education, smoking, and alcohol consumption. Multivariable logistic regression analyses were conducted to assess the association between multimorbidity and UI.ResultsThe prevalence of UI was 5.9% in this sample. UI was more frequent in the presence than in the absence of each one of the 30 chronic conditions (P<0.001). The proportion of people with UI was also higher in the multimorbidity than in the no-multimorbidity group (9.8% versus 0.7%, P<0.001). After adjusting for several potential confounders (that is, sex, age, marital status, education, smoking, and alcohol), there was a significant and positive relationship between multimorbidity and UI (odds ratio = 5.02, 95% confidence interval [CI] = 3.89 to 6.59, P<0.001).ConclusionIn this large sample of Spanish individuals aged ≥15 years, suffering from multimorbidity was associated with a significantly higher level of UI.