Geographic variation in cardiometabolic risk factor prevalence explained by area-level disadvantage in the Illawarra-Shoalhaven region of the NSW, Australia

Abstract

Cardiometabolic risk factors (CMRFs) demonstrate significant geographic variation in their distribution. The study aims to quantify the general contextual effect of the areas on CMRFs; and the geographic variation explained by area-level socioeconomic disadvantage. A cross sectional design and multilevel logistic regression methods were adopted. Data included objectively measured routine pathology test data between years 2012 and 2017 on: fasting blood sugar level; glycated haemoglobin; total cholesterol; high density lipoprotein; urinary albumin creatinine ratio; estimated glomerular filtration rate; and body mass index. The 2011 Australian census based Index of Relative Socioeconomic Disadvantage (iRSD) were the area-level study variables, analysed at its smallest geographic unit of reporting. A total of 1,132,029 CMRF test results from 256,525 individuals were analysed. After adjusting for individual-level covariates, all CMRFs significantly associated with IRSD and the probability of higher risk cMRfs increases with greater area-level disadvantage. though the specific contribution of IRSD in the geographic variation of CMRF ranged between 57.8 and 14.71%, the general contextual effect of areas were found minimal (ICCs 0.6-3.4%). The results support universal interventions proportional to the need and disadvantage level of populations for the prevention and control of CMRFs, rather than any area specific interventions as the contextual effects were found minimal in the study region. The prevalence of cardiometabolic risk factors (CMRFs) varies geographically 1,2. Previous research has reported higher prevalence of CMRFs in certain localities: typically in areas of higher socioeconomic disadvantage 3-23. However, frequently these studies have been based on measures of association or geographical variance rather than reporting clustering or the share of the total variance that is at the area-level 3-23. Quantifying the clustering and the proportion of geographic variation in CMRFs contributed by area-level socioeconomic disadvantage can aid in designing appropriate area-level approaches to help prevent CMRFs. Chronic and uncontrolled CMRFs predispose individuals to the development of cardiovascular disease (CVD), which continues to be the leading cause of health care expenditure and premature mortality worldwide 24. In Australia, a social gradient is observed in the prevalence of many chronic conditions including various CMRFs (e.g.diabetes and chronic kidney disease) 25. Generally, Australians enjoy better health than people in many other countries in the world. However, within Australia this better health is not equally distributed 26. It is