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[Annual patient volume and survival of very low birth weight infants (VLBWs) in Germany--a nationwide analysis based on administrative data].

BACKGROUND
Despite numerous international analyses addressing survival of very low birthweight infants (VLBWs) in relation to patient volume, only few regional analyses from Germany exist. Thus, the aim of this study was to perform analyses on a nationwide database relating to this topic.


MATERIALS AND METHODS
We used nationwide hospital claims data according to data exchange processes designated in section sign 301 Social Security Code, of patients insured with the local healthcare insurance fund (AOK), with a hospital admission weight of 300-1 499 g, an age of less than 29 days, and a hospital discharge date between 1 Jan 2002 and 30 June 2006. Mortality within 30 days of hospital admission was used as end point. Crude and risk adjusted analyses were performed using logistic regression.


RESULTS
A comparison with federal statistics data showed that our dataset covers 28 % of all VLBWs born in Germany during the study period. 9 487 VLBWs could be included in risk adjusted volume-outcome analyses. Significantly increased risk adjusted 30-day-mortality rates in smaller units were observed using different thresholds. The relationship was more pronounced in the most recent time period starting from 2004.


CONCLUSION
Adoption of a minimum VLBW patient volume in addition to the structural requirements consented by the Federal Joint Committee (G-BA) seems reasonable, to maintain or improve the quality of VLBW health care provision in Germany.