Effect of a national primary care reform on avoidable hospital admissions (2000–2015): A difference-in-difference analysis

In 2006 a major primary care reform was initiated in Portugal. The most significant aspect of this reform was the creation of a new organizational model of primary care provision: Family Health Units (FHUs), consisting of small voluntarily constituted multidisciplinary teams that have functional autonomy and are partly financed through capitation and pay-for-performance. The creation of FHUs sought to increase access to care and to chronic disease management by improving the long-term relationship between health professionals and patients. The objectives of this study are to evaluate the impact of the FHUs implementation on population health outcomes, measured by the rate of hospitalizations for ambulatory care sensitive conditions (ACSC), i.e. avoidable hospital inpatient admissions, and to explore the effectiveness of the pay-for-performance in primary care by analysing the subset of disease specific hospitalizations for ACSC related to the financial incentives. Using data from 276 Portuguese municipalities from 2000 to 2015 (n = 4416) and exploiting the gradual introduction of the FHUs over time, we used a difference-in-differences approach contrasting the evolution of the hospitalization rate for ACSC in municipalities that implemented or not the FHUs. We then explored heterogeneous effects by incentivized (diabetes and hypertension) and non-incentivized disease-specific rates of hospitalizations for ACSC. During the period under analysis, 448 FHUs were created in 126 municipalities. No significant impact of the FHUs implementation on the reduction of the hospitalization rate for ACSC was found. This result also held for the incentivized hospitalizations for ACSC. We only found a statistically significant effect of the FHUs implementation in the reduction of one non-incentivized area (the rate of urinary tract infection ACSC). Our results question the capacity of this payment mechanism to achieve better health outcomes, and invites a more careful and evidence-based action toward its wider diffusion.