Expansion of primary healthcare and emergency hospital admissions among the urban poor in Rio de Janeiro Brazil: a cohort analysis

Background: Robust evidence on the relationship between primary care and emergency admissions is lacking in low- and middle-income countries. This study evaluates how the phased roll out of the family health strategy (FHS) to the urban poor in Rio de Janeiro Brazil affected emergency hospital admissions and readmissions from ambulatory-care sensitives conditions (ACSCs). Methods: A cohort of 1.2 million adults in Rio de Janeiro city were followed for five years (Jan 2012 to Dec 2016). The association between FHS use and the likelihood of emergency hospital admissions and 30-day readmissions were evaluated using multi-level Poisson regression models with inverse probability treatment weighting and regression adjustment (IPTW-RA) for socioeconomic and household characteristics. Inequalities in associations were examined across groups of causes and by key socioeconomic groups. Results: Records from 2,551,934 primary care consultations and 15,627 admissions were analysed. In IPTW-RA analyses, each additional FHS consultation was associated with a 3% lower rate of ACSC admission (RR: 0.97; 95%CI: 0.95, 0.98), a 63% lower rate of 30-day readmissions from any non-birth cause (RR: 0.37; 95%CI: 0.30, 0.46), and an 57% lower rate of 30-day readmissions from ACSCs (RR: 0.43; 95%CI: 0.33, 0.55). Individuals who were older, had the lowest educational attainment, were unemployed, and had higher incomes had larger reductions in ACSC admissions associated with FHS use. Interpretation: Investment in primary care is important for reducing emergency hospital admissions and their associated costs in LMICs. Funding: DFID/MRC/Wellcome Trust/ESRC.