Background: Prevalence of obesity among inpatients and emergency (I&E) presentations in South Australian (SA) tertiary public hospitals remains unclear. While national data suggest obesity is under-coded in hospitals, this has not been specifically reviewed in SA (1,2,3).
Aims: The primary aim was to determine the prevalence of obesity in I&E presentations across SA’s metropolitan tertiary hospitals, comparing different local health networks (LHN) Central (CALHN), Southern SALHN), and Northern Adelaide (NALHN). Secondary aims included evaluating obesity-related clinical coding, its impact on comorbidities, and length of stay (LOS).
Methods: A cross-sectional point prevalence study of obesity in I&E presentations was conducted across major SA tertiary hospitals using electronic health record data over two consecutive days in February 2024. Body Mass Index (BMI) was calculated from height and weight data to classify patients as obese (BMI ≥30kg/m2) or non-obese (BMI <30kg/m2). ICD-10 codes were reviewed. Mann-Whitney U and Chi-square tests were used for group comparisons, and obesity prevalence assessed using generalised linear model.
Results: Of the 3914 I&E patient data collected, 3077 (78.6%) had BMI determined. Overall obesity prevalence was 31.8% (n=979), broadly comparable to the Greater Adelaide obesity rates (33.4%) (4). Prevalence differed significantly across LHNs (p=0.048), with NALHN showing the highest rates. Obese patients were younger, more likely female, Australian-born, and had higher rates of type1 and type 2 diabetes (32.8% vs 21.7%, p<0.001), obstructive sleep apnoea (2.4% vs 0.4%, p<0.001) and osteoarthritis (4.0% vs 1.6%, p<0.001). Obesity was coded in only 2.7% of cases. Class III (BMI ≥ 40.00 kg/m2) obesity was highest in NALHN (8.4%) and exceeded general SA rates (3.9%). LOS was longer in the non-obese group (Median:13 days vs 10 days, p<0.001).
Conclusion: Obesity prevalence among I&E patients in SA tertiary hospitals reflects community levels, but Class III obesity is overrepresented. Clinical coding for obesity remains low.