Examining the Trade-off Between NICU Length of Stay and Postdischarge Monitoring: An Instrumental Variables Approach

Treatment of very low birth weight infants in a neonatal intensive care unit (NICU) can be expensive, particularly in rural areas, but may potentially reduce long-term treatment costs and improve short- and long-term health outcomes. Few studies look at this trade-off. We employed an instrumental variables approach (fuzzy discontinuity) based on changes in practice for the treatment of very low birth weight infants in a perinatal referral center's NICU in 2000-2001. The strategy of keeping infants in a NICU longer reduced the likelihood of discharge with an apnea/cardio monitor. The primary instrumental variables specification estimated that every additional 100g of discharge weight reduced the likelihood of discharge with an apnea/cardio monitor by 4.8%. Extending an infant's length of stay (LOS) thus has important benefits. Greater expenses on days in the NICU are partially compensated by reduced monitoring post discharge. In contexts where postdischarge monitoring is particularly difficult or expensive, extending LOS may be cost effective and potentially improve outcomes.