Often used indicators for the quality of primary care are hospital admissions rates for conditions which are potentially avoidable by well-functioning primary care. Such hospitalizations are frequently termed as ambulatory care sensitive conditions (ACSCs).

We aim to investigate which characteristics of primary care organization influence avoidable hospitalization for chronic ACSCs.

MEDLINE, Embase and SciSearch were searched for publications on avoidable hospitalization and primary care. Studies were included if peer reviewed, written in English, published between January 1997 and November 2013, conducted in high income countries, identified hospitalization for ACSC as outcome measures and researched organization characteristics of primary care. A risk of bias assessment was performed to assess the quality of the articles.

A total of 1778 publications were reviewed, of which 49 met inclusion criteria. Twenty-two primary care factors were found. Factors were clustered into four primary care clusters: system-level characteristics, accessibility, structural and organizational characteristics and organization of the care process. Adequate physician supply and better longitudinal continuity of care reduced avoidable hospitalizations. Furthermore, inconsistent results were found on the effectiveness of various disease management programs in reducing hospitalization rates.

Available evidence suggests that strong primary care in terms of adequate primary care physician supply and long-term relationships between primary care physicians and patients reduces hospitalizations for chronic ACSCs. There is a lack of evidence for the positive effects of many other organizational primary care aspects, such as specific disease management programs.