[Patient safety in view of specialization, minimum quantity and regionalization].
BACKGROUND: The introduction of a set of volume standards in Germany 2003 has lead to a discussion whether statutory volume thresholds as well as the enhancement of further regionalization would do more harm than good. The objective of this study is to evaluate the influence of specialization, volume standards and regionalization on patient safety. METHODOLOGY: According to study objectives patient safety was defined as "hospital mortality", "hospital morbidity", "long-term outcome" and "readmission rate". A MEDLINE analysis was performed using the following terms: "hospital", "volume", "outcome", "specialization", "regionalization", "readmission", "patient safety" and "review". In order to lower the high number of studies only journals published between 1999 and 2004 with high impact factors were used for evaluation. RESULTS: A vast majority of studies have been published in recent years finding significant higher probabilities for good outcome in high volume hospitals compared with low volume hospitals. However, the magnitude of the volume - outcome relation varies greatly among procedures and conditions, showing a strong and persistent relation for severe ill patients and high-risk procedures. Patient safety can also be influenced by surgeon volume and specialization. CONCLUSIONS: Specialization, volume standards and regionalization have shown to be effective in improving patient safety. Further studies are needed to estimate the potential benefits of this strategy to foster patient safety in German hospitals.