The relationship between avoidable hospitalization and accessibility to primary care: a systematic review

BACKGROUND: Avoidable hospitalization (AH) has been widely studied as a possible measure of the performance of primary health care (PHC). However, studies examining the relationship between the efficiency and quality of PHC and AH have found mixed results. Our study aims at highlighting those factors related to the relationship between AH and accessibility to PHC in different countries. METHODS: We conducted a systematic search for peer-reviewed studies published between 1990 and October 2010 in English, German, French, Italian or Spanish and indexed primary electronic databases. RESULTS: The final analysis was conducted on the basis of 51 papers. Of them, 72.5% revealed a significant inverse association between the indicator of PHC accessibility and rates of AH. Indicators of PHC calculated at individual level are more likely to reveal contradictory aspects of the relationship between rates of AH and indicators of quality and PHC accessibility. CONCLUSIONS: Most studies confirmed the expected relationship between indicators of PHC accessibility and hospitalization for ambulatory care sensitive conditions (ACSCs), showing lower hospitalization rates for ACSC in areas with greater access to PHC. The findings support the use of ACSC hospitalization as an indicator of primary care quality, with the precaution of applying appropriate adjustment factors.