2.2. Design and study population

Data for this study were obtained from the CODA‐G4 study, an observational longitudinal cohort study that started data collection in 2011 and followed 513 homeless people in the four major cities in the Netherlands (i.e. Amsterdam, Rotterdam, The Hague and Utrecht) for a period of 2.5 years. It consisted of four measurement waves, that is, baseline, and six‐month, 1‐year, and 2.5‐year follow‐up. Procedures of sampling, data collection and response rates have been published previously (Van Straaten et al., 2016).

In this study, we included participants who completed all four waves. At baseline, all study participants satisfied the criteria set by the four major Dutch cities for registering at the social relief system and starting an individual programme plan. These included: aged ≥18 years, having legal status in the Netherlands, having stayed in the region of social relief application for at least two years during the last three years, having abandoned the home situation and not being sufficiently competent to live independently. In the Netherlands, registration at the social relief system is required to get access to social relief facilities (e.g. a night shelter). The individual programme plan was in 2006 implemented as part of the Strategy Plan for Social Relief (Dutch Government & four major cities, 2006), which aimed to provide homeless people in the four major Dutch cities with an income, suitable accommodation and effective support and to reduce the level of public nuisance caused by them. Most persons eligible for this study were literally homeless (e.g. sleeping in a night shelter or transitional accommodation, or staying temporarily with family, friends or acquaintances); a minority were either residentially homeless (e.g. residing in an institution) or housed but about to be evicted. At follow‐up, still being homeless was not required. Hence, the term “homeless” refers in this paper to people who had been homeless at baseline and were either still or formerly homeless at follow‐up.