Prevalence of Multimorbidity in Lithuania: Insights from National Health Insurance Fund Data

(1) Background: As the burden of multimorbidity is increasing worldwide, little is known about its prevalence in Lithuania. We aimed to estimate the prevalence of chronic conditions and multimorbidity among Lithuanian adults and assess their impact on healthcare utilization. (2) Methods: A retrospective analysis of the Lithuanian National Health Insurance Fund database was performed in 2019. Multimorbidity was defined as having two or more chronic conditions. (3) Results: Of the Lithuanian population, 1,193,668 (51.5%) had at least one chronic condition, and 717,386 (31.0%) had multimorbidity. Complex multimorbidity (CM) was present in 670,312 (28.9%) patients, with 85.0% having complex cardiac multimorbidity (CCM) and 15.0% having complex non-cardiac multimorbidity (CNM). Multimorbidity increased with age, from 2% at age 18–24 to 77.5% at age 80 and above, and was more prevalent among women (63.3% vs. 36.7%, p < 0.001). One-third of multimorbid patients were hospitalized at least once per year, with half staying for a week or longer. CCM patients were more likely to be hospitalized, rehospitalized, and have more primary care visits (OR: 2.23, 1.60, 4.24, respectively, all p < 0.001). (4) Conclusions: Multimorbidity in Lithuania increases with age and affects women more. Chronic cardiovascular diseases contribute to a higher prevalence of multimorbidity and a more significant burden on the healthcare system.