BACKGROUND Multimorbidity is a common problem in elderly populations and is significantly associated with functional decline, disability, and mortality. However, the sex-specific characteristics of multimorbidity and its effect on patients' quality of life (QOL) have not been clearly established.

METHODS We analyzed the Korean National Health and Nutrition Examination Survey database. EuroQol 5D (a standardized health outcomes measurement instrument that includes 2 dimensions, the EuroQol 5 Dimension [EQ-5D] index score and the EuroQol visual analogue scale [EQ-VAS]) was used to evaluate QOL. Multimorbidity was evaluated using data on blood pressure measurements, blood chemistry examinations, and anthropometric assessments, as well as a survey that assessed health status.

RESULTS A total of 1419 patients aged ≥65 years were included in the analysis (age = 72.40 [0.19] years; 39.3% men). Multimorbidity was significantly associated with being a woman; however, it was not associated with age. The EQ-5D index score and EQ-VAS score were significantly lower in patients with multimorbidity, especially among the elderly women. The inverse association between QOL and the number of chronic diseases was maintained without a floor effect. Hypertension was the most common disease; however, QOL was significantly associated with musculoskeletal disease, stroke, and depression, all of which were more common in female patients. There was no significant difference in QOL between men and women with similar levels of comorbidity.

CONCLUSION Both the amount and pattern of chronic diseases have been associated with QOL in elderly populations. Elderly women have low levels of QOL due to multimorbidity and a higher prevalence of chronic disease, which is related to impaired QOL.