Background This study investigated the impact of the Healthy Housing Programme in reducing acute hospitalisations in South Auckland, New Zealand. The programme involved house modifications to reduce overcrowding, insulation and ventilation improvements, and health and social service assessments, referrals and linkages.

Methods An intervention evaluation was used. Participants in the programme were considered cases following their house's intervention and counterfactuals/controls prior to the intervention. Rigorous age-censoring was used to construct a case-counterfactual comparison. 9736 residents of 3410 homes were involved in the programme from September 2001 to December 2007. All lived in areas of relative deprivation (NZDep01=decile 10) and almost all self-identified as Pacific ethnic group. The main outcome measure was acute hospitalisation rates before, during and after a health and housing intervention. Hospital data were gathered from July 1999 to January 2009.

Results In the post-intervention group, people aged 5–34 years had a HR of 0.77 (95% CI 0.70 to 0.85) for acute hospitalisations compared to the counterfactual (pre-intervention). For children aged 0–4 years the HR was 0.89 (95% CI 0.79 to 0.99); a non-significant increase occurred in adults aged 35 years plus. When the causes of hospitalisation were restricted to those related to housing, further falls in the HRs were seen: 0.88 (95% CI 0.74 to 1.05) for 0–4 year olds and 0.73 (95% CI 0.58 to 0.91) for 5–34 year olds.

Conclusion A package of care that addresses housing conditions that impact on health and improves access to health and social services is associated with a reduced acute hospitalisation rate for 0–34 year olds.