Health service use and predictors of high health service use among adults experiencing homelessness: a retrospective cohort study

Objective: To describe the characteristics and cost of health service use of a cohort of 2,140 people attending homeless hostel clinics, and identify predictors of high health service use and time to readmission. Method: A retrospective cohort study of 2,140 adults who attended a homeless hostel clinic and were hospitalised in New South Wales (NSW) using linked clinic, health and mortality data from 1 July 2008 to 30 June 2021. Multivariable logistic regression examined predictors of high health service users. Results: There were 27,466 hospital admissions, with a median cost of A$81,481 per person, and a total cost of A$548.2 million. Twenty per cent of the cohort were readmitted within 28 days and 27.4% were classified as high users of health services. Factors associated with high use were age >= 45 years, female (AOR: 1.52; 95%CI 1.05-2.22), the presence of a mental disorder, substance use disorder (AOR: 1.36; 95%CI: 1.03-1.82), or if the person had been homeless for >1 year (AOR: 1.31; 95%CI: 1.06-1.62). Conclusions and implications for public health: The high health costs generated by homeless adults confirm the need to develop models of supported housing with a focus on integrated care, improved referral pathways and better coordination with community-based support agencies.