Concordance of comorbidity in diabetes and the burden of the disease – 11 years cohort

Sophia Eilat-Tsanani, Avital Margalit, Liran Nevet Golan

Keywords: diabetes mellitus, comorbidity, health services, family doctor, mortality

Background:
The burden of type 2 diabetes is growing, not only through increased incidence, but also through its comorbidities. Concordant comorbidities for type 2 diabetes, such as cardiovascular diseases, are considered expected outcomes of the disease or disease complications, while discordant comorbidities are less extensively addressed under diabetes management.

Research questions:
Is there a difference in the impact on health between concordant and discordant comorbidities of persons with diabetes?

Method:
A retrospective cohort study following 11 years after persons with new onset diabetes. Persons were stratified into groups according to comorbidities: concordant, discordant, combined (concordant and discordant) or absent. The use of health services and mortality were compared between the groups according to sociodemographic variables.

Results:
The study sample included 9,725 persons, most of them having the combination of concordant and discordant comorbidities (75%), detected both before and after diagnosis of type 2 diabetes. Rheumatic and gastrointestinal diseases were leading in discordant comorbidities.
Those aged 45-65 years were at higher risk for having combined comorbidities [OR=4.9; 95% CI: 3.9-6.2), as were those aged 65 years or more [OR=4.8; 95% CI: 3.8-6.1]. Women were at lower risk than men for having combined comorbidity [OR=0.87; 95% CI: 0.7-1.0], similar to other types of comorbidities.

The comparison between people with combined comorbidities to those with concordant and discordant comorbidities only shows:
• More comorbidities (7.3 vs. 2.8 and 2.0 respectively)
• More visits/year to family physicians (17.3 vs. 11.6 and 9.7 respectively)
• A higher risk of death in persons with both combined comorbidities and discordant only comorbidities (HR=33.4; 95% CI: 12.5-89.2 and HR=33.5; 95% CI: 11.7-95.8).

Conclusions:
The findings highlight the contribution of discordant comorbidity to the burden of the disease. The high prevalence of the combination of both concordant and discordant comorbidities, and their appearance before the onset of type 2 diabetes, indicates a continuum of morbidity.

Points for discussion: