Cohort profile: Swedish families of the 1990s (SWIFT90)

The Swedish Families of the 1990s (SWIFT90) is a population-based national register cohort that follows everyone born between 1990 and 1999, their parents and siblings. The cohort was set up primarily to investigate factors associated with biological parents' involvement with child welfare services and their outcomes following child(ren) placement in out-of-home care (OHC) under the research project 'Drivers of inequalities of families involved in child welfare services (DRIVERS)'.

This cohort is defined as families consisting of parents and their children, of which at least one was born between 1990 and 1999 in Sweden, which totals 1 075 037 children. The children are linked to both (adoptive or biological) parents and their siblings, so the total number of individuals in the SWIFT90 yields a total sample of n=3 292 417. These families are followed through multiple national registers including information on income, education, inpatient care, mortality and criminal offences. SWIFT90 compiles administrative data spanning from 1960 to 2022, which reflects the most recent data available at the time of the data request.

SWIFT90 provides information on 61 982 parents (fathers=31 028; mothers=30 954) with children placed in OHC and their respective children (38,084). Several covariates could be assessed for the parental generation, therefore, providing a comprehensive picture of socioeconomic and health-related aspects of families with children born in the 1990s and placed in OHC in Sweden.

SWIFT90 will be used to investigate the socioeconomic and health trajectories of families involved with the child welfare system. With this cohort study ia possible to examine whether the inclusion of certain covariates alters the association between parental characteristics and child welfare outcomes. Future studies could also guide initiatives to prevent vulnerable circumstances among biological parents from escalating to the point where child placement into OHC becomes necessary. Additionally, they could help enhance the conditions of biological families and support opportunities for reunification after placement has occurred.