Cost-effectiveness analysis of Housing First intervention with an independent housing and team support or homeless people with severe mental illness: a Markov model informed by a randomized controlled trial

•Measuring the cost effectiveness of HF may help stakeholders in decision-making for scaling-up.•Cost-effectiveness was assessed by a Markov model and using data from a RCT.•Housing First was cost effective in homeless people with severe mental disorders.•HF costs were all offset by savings in other services over the first 14 years.