The correlates and consequences of multimorbidity in Singapore

Individuals who are older, female, of lower socioeconomic status and who suffer from mental disorders are more likely to experience increasing multimorbidity, according to a recent Singapore study.

“These findings emphasize the association between multimorbidity and sociodemographic factors,” said researchers. “Healthcare policies need to take sociodemographic factors into account when tackling multimorbidity in a population.”

Accessing the deidentified Singapore Eastern Regional Health System database, researchers identified 1,181,024 individuals (mean age, 39.6±22.1 years; 51.2 percent female) for inclusion in the present population-based cross-sectional study. More than a quarter (26.2 percent) had multimorbidity, which was defined as the presence of two or more chronic conditions. [JAMA Netw Open 2019;2:e1915245]

Multimorbidity occurred at a higher frequency in females than in males (26.8 percent vs 25.6 percent). Only 2.9 percent of the study population had both physical and mental diseases.

Age also emerged as a potential predictor of multimorbidity. The mean number of chronic diseases increased with age, such that more than half of the participants had at least one chronic condition by 50 years. A similar proportion was positive for multimorbidity by 60 years of age.

An inverse effect was observed for socioeconomic status. Multimorbidity was reported in 41.6 percent of participants in the low socioeconomic bracket, more than twice that in the high bracket (20.1 percent). The prevalence of multimorbidity in participants 40–60 years of age in the lowest socioeconomic bracket was similar to their high-status counterparts who were 10 years older.

Mental health was likewise an important consideration for multimorbidity. The two shared a direct proportionality which was mediated by socioeconomic status. That is, mental health issues were significantly more prevalent among those in the lower brackets (5.2 percent vs 2.1 percent; p<0.001), in accordance with excess multimorbidity burden.

Females were also more likely than males to have mental health conditions, reflecting the sex-based asymmetry in multimorbidity burden.

“Such an understanding of the epidemiologic characteristics and the implications of multimorbidity is necessary for better risk stratification of multimorbidity, integrated coordination of multiple appointments for patients and more effective communication among healthcare professionals to better manage patients’ varied clinical needs,” said the researchers.

Aside from sociodemographic determinants, the researchers also determined the impact of multimorbidity on healthcare use. Those with diabetes and renal disease, for example, had the highest polyclinic comorbid care costs. Angina with renal disease comorbidities was associated with the highest emergency department costs.

Patients suffering from osteoarthritis-related chronic conditions and asthma incurred the greatest general practitioner visit costs. The highest specialist outpatient costs were recorded in patients with comorbid cancer and chronic kidney disease.

Overall, “[t]hese findings suggest that holistic management of multimorbidity is warranted, and care must be customized to meet the needs of patients with different multimorbidity patterns,” the researchers said.