The Epidemiology of Infective Endocarditis in New South Wales, Australia: A Retrospective Cross-Sectional Study From 2001 to 2020

Objectives This study aimed to investigate the demographic differences amongst patients diagnosed with infective endocarditis (IE), predictors of adverse events, and the association between clinical decision-making and adverse health outcomes amongst patients with IE. Design A retrospective cross-sectional study was conducted using the New South Wales (NSW) Admitted Patient Data Collection (APDC) from the Centre for Health Record Linkage (CHeReL). Participants All patients (N=18,044) from 2001 to 2020 in New South Wales who received a diagnosis of IE using ICD-10-AM diagnostic code 133.0 were included. Methods Categorical variables were compared using the chi-square test or Fisher's exact test, while the t-test was used for continuous variables. The association between clinical decision-making and adverse health out-comes amongst patients with IE were examined via generalised linear mixed models. Results Sex, age, birthplace and referral impacted clinical decision-making, in-hospital death and severity of the disease. Women experienced a higher risk of death and fewer escalations of care. Admission and mortality increased with age, with those aged 60 years and above responsible for 60.8% of hospitalisations. Despite octogenarians making up one -fifth of admissions and having the worst mortality rate (15.1%), they experi-enced only one in 10 intensive care (ICU) admissions. Overseas-born patients had fewer escalations of care and experienced less severe disease if referred by a medical practitioner. One out of 10 admissions that resulted in a hospital death were given non-emergency status, and one in two ICU patients died in hospital. Conclusions Sex, age, place of birth, and clinical decision-making were important predictors of severe disease and death in hospital, lending weight that health care clinical decisions may adversely impact health outcomes for populations of interest.