Impact of substandard housing on early child development in high-income countries: a systematic review

OBJECTIVE: To collate and systematically review the evidence on the impact of substandard housing on early child development in high-income countries. DESIGN: Systematic review. METHODS: Five databases (Medline, Emcare, Web of Science, Scopus and PsycInfo) and relevant grey literature were searched between June and July 2024. Records were screened to include studies which explored the association between substandard housing and cognitive, language, motor, social, emotional and/or behavioural development in children aged 0-8 years living in high-income countries. Studies which only explored lead, radiation or secondhand smoking exposures were excluded. Data were extracted from relevant articles and reported via a narrative synthesis. Risk of bias was assessed using the Risk of Bias in Non-Randomised Studies of Exposures tool. Certainty of findings was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. All screening, data extraction and 20% of quality assessment were performed independently by a second assessor. RESULTS: 6258 records were screened, from which 25 studies were included, representing >2 29 000 children from seven high-income countries. Studies mostly explored home air quality and overcrowding. Moderate certainty evidence was found for associations between mould, damp, condensation, overcrowding, hygiene and safety issues and unclean heating/cooking fuels and poorer early child development. Low certainty evidence was found for an inverse relationship with nitrogen dioxide, particulate matter and xylene levels. Very low certainty evidence was found for associations between limited home resources and poorer child development. ORs ranged from 1.28 to 3.53. All studies had a high or very high risk of bias. Meta-analysis was not possible due to heterogeneity. CONCLUSIONS: Policymakers and professionals working with children in healthcare, social and education settings should be aware that housing conditions may impact child development. Research is needed to further evaluate the impacts of substandard housing on childhood development, but notwithstanding this, our review supports the growing momentum for improving living situations for young children. FUNDING: No specific funding was received for this study. PROTOCOL REGISTRATION: PROSPERO: CRD42024564320.