Socioeconomic disparities in the prevalence of comorbid chronic conditions among Canadian adults with cancer.

OBJECTIVE To evaluate the prevalence of comorbid chronic conditions among Canadian adults with cancer and the impact of socioeconomic background on the distribution of these conditions. METHODS Canadian Community Health Survey (CCHS) 2017-2018 dataset was accessed and individuals with complete information about cancer history were reviewed. The prevalence of the following 10 chronic conditions was reviewed: asthma, chronic obstructive pulmonary disease, arthritis, hypertension, hypercholesterolemia/hyperlipidemia, heart disease, stroke, diabetes, mood disorder, and anxiety disorder. Stratification of the prevalence was done according to age, sex, and racial subgroups. Multivariable logistic regression analysis was done to evaluate the association between sociodemographic characteristics and having multiple comorbid conditions. RESULTS A total of 104,362 participants were included in the current study (including 10,782 participants with a history of cancer; and 93,580 participants without a history of cancer). Among all age, sex, and race strata, participants with a history of cancer were more likely to have multiple chronic conditions (p < 0.05 for all comparisons). The most common three individual comorbid conditions among participants with cancer were arthritis (40.2%), hypertension (36.1%), and hypercholesterolemia (25.2%); while the most common cancer-comorbidity triad among participants with cancer was cancer/arthritis/hypertension (17.7%). In a multivariable logistic regression analysis among participants with cancer, the following sociodemographic factors were associated with having multiple comorbid conditions: older age (OR for age 80+ versus age 18-20 years: 8.32; 95% CI: 5.17-13.39), indigenous racial group (OR: 1.94; 95% CI: 1.43-2.63) and lower income (OR for income ≥80,000 Canadian dollars (CAD) versus income: ≤20,000 CAD: 0.29; 95% CI: 0.23-0.37). CONCLUSION History of cancer is associated with a higher probability of many comorbid conditions. This excess comorbidity burden seems to be unequally shouldered by individuals in the lower socioeconomic stratum as well as minority populations.