Very low birth weight hospital volume and mortality: an instrumental variables approach.

ABSTRACT:

Background

Previous studies of very low birth weight (VLBW) hospital volume effects on in-hospital mortality have used standard risk-adjusted models that only account for observable confounders but not for self-selection bias due to unobservable confounders.

Objective

To assess the effects of hospital volume of VLBW infants on in-hospital mortality while explicitly accounting for unobservable confounders and self-selection bias using an instrumental variables (IV) model.

Methods

The sample includes 4553 VLBW infants born in 63 hospitals in 2000-2004 in New Jersey. We use IV analysis with the differences between the patient's distances to the nearest low (<50 VLBW infants annually), moderate (51-100 infants annually), and high (>100 VLBW infants annually)-volume hospit

SUBMITTER: Wehby GL 

PROVIDER: S-EPMC3388172 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature