Effect of socio-demographic factors on the association between multimorbidity and acute care service use: a population-based retrospective cohort study

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background: This study explores how a broad-range of socio-demographic factors shape the relationship between multimorbidity and one-year acute care service use (i.e., hospital, emergency department visits) among older adults in Ontario, Canada. Methods: We linked multiple cycles (2005-2006, 2007-2008, 2009-2010, 2011-2012) of the Canadian Community Health Survey (CCHS) to health administrative data to create a cohort of adults aged 65 and older in Ontario. Twelve chronic conditions identified from the administrative data were used to estimate multimorbidity (number of chronic conditions). We identified acute care service use over one year from the administrative data. We examined the relationship between multimorbidity and service use stratified by a comprehensive range of socio-demographic variables available from the CCHS. Logistic and Poisson multivariable regressions were used to explore the association between multimorbidity and service use and the role of socio-demographic factors in shaping this relationship. Results: Of the 28,361 members of the study sample, 60% were between the ages of 65 and 74 years, 57% were female, 72% were non-immigrant, and over 75% lived in an urban area. Emergency department visits and hospitalizations consistently increased with the level of multimorbidity. Stratified analyses revealed further patterns, with many being similar for both services – e.g., the odds ratios for both services were higher at all levels of multimorbidity for men, older age groups, and those with lower annual household income. Rurality and immigrant status appeared to impact emergency department use (higher in rural residents and non-immigrants) but not hospitalizations. Multimorbidity and most socio-demographic variables remained significant predictors of acute care service use in the multivariable regressions. Conclusions: Strong evidence links multimorbidity with increased acute care service use. This study showed that socio-demographic factors did not modify the relationship between multimorbidity and acute care service use, they were independently associated with acute care service use. Acute care service use was associated with perceived physical and mental health status as well as psychosocial factors, suggesting that optimizing service use requires attention to self-reported health status and social determinants, with programs that are multifaceted and integrated across the health and social service sectors.</jats:p>