Infectious disease outcomes associated with inadequate housing and access to healthy living practices in Australia: a systematic review.

Objectives: Inadequate housing and living conditions underpin significant health and wellbeing inequality in Australia, particularly for Indigenous people. This review aimed to define infectious disease (ID) outcomes used to measure the health impact of inadequate housing in Australia within a research context. Design: A systematic review of published studies following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Data sources: Four online databases were searched in May 2024 with no date restrictions using terms relating to housing, ID and Australia. Results were screened in Covidence. Eligibility criteria: Studies were included if they measured both housing exposures and ID outcome variables among any population group in Australia. Both quantitative and qualitative designs were considered. Data extraction and synthesis: Data were extracted from 81 studies. Exposures and outcomes were classified according to the Healthy Living Practices (HLPs) and the International Classification of Primary Care (ICPC-2) body system classes, respectively. Acute infections and chronic post-infectious sequelae were considered ID outcomes. Descriptive statistics were calculated and ID-HLP associations were synthesised and narratively described. Methodological quality was assessed from both biomedical and Indigenous perspectives using relevant appraisal tools. Results: Most studies (79%) were published within the past 25 years and more than half (60%) involved remote-living Indigenous children and families. A total of 176 measured ID outcomes and 571 ID-HLP associations were tested. Exposures were frequently related to the negative effects of crowding (HLP5), unsafe wastewater treatment/drinking water (HLP3) and reduced capacity for washing people (HLP1). Skin, respiratory and digestive system infections were the most common ID outcomes, followed by eye and ear infections and post-infectious cardiovascular sequelae. Studies relied on intensive data collection methods and bespoke definitions. Conclusions: Substantial research has described ID outcomes associated with inadequate housing in Australia. However, high-quality evidence is lacking, and methodological heterogeneity between studies limits the synthesis and actionability of this work. We recommend prospective classification of housing exposures according to the HLPs and encourage the exploration of routinely collected primary care data. Agreed measurement approaches and data collection tools that are consistent with Indigenous Data Sovereignty principles would add value. PROSPERO registration number: CRD42024541393.