Introduction: Few studies have attempted to evaluate the relationship between medical and nursing staffing and neonatal outcomes providing inconclusive evidence. The purpose was to assess whether morbidity and mortality of VLBW infants are associated with levels of patient volume, provision and training of medical and nursing, and if exist differences between public and private centers.
Material and methods: Neonatal outcomes of all VLBW inborn infants consecutively admitted to 15 South-American NICUs between 2005 and 2007 were retrospectively studied. Data of patient volume and provision of medical & nursing resources were obtained from questionnaires.
Outcome measures: death before discharge, incidence of severe IVH, BPD, ROP and late onset sepsis, adjusted for initial risk (Neocosur score). Units were categorized using total annual number of newborns < 1500 g (low < 50, medium 50-100, and high >100) and in public and private centers.
Results: 2019 preterms were admitted. Mean (SD) gestational age, birth weight and initial risk were 28.9 (0.7) weeks, 1088 (53) g and 0.24 (0.04) respectively. Mortality varied among units and ranged between 6 to 38% (mean 23.2%), as well as other outcomes (median, intercuartil range [ICR]): severe IVH 7.3% (6-14); BPD 20.8% (15-43); ROP ≥ III 5.6% (2.7-8.5); late sepsis 23% (15-29). Staff provision were: daily medical hours (median, ICR) 2.6 (1.4-4.0), full-time (> 40 h/week) equivalent physicians (mean, SD) 15(8), daily nurse hours 6.1 (4.3-7.9), full-time (> 40 h/week) equivalent nurses 32 (22-56) and nurses-to-infant ratio 0.78 (0.52-0.92). Median daily NICU census was 9.8 (8.9-12). A low medical hours provision was significantly associated with increased mortality (OR 1.30 [95% CI: 1.04-1.76], p= 0.020); on the other hand low nurse provision was significantly associated with increased risk of mortality, adjusted by mother age and initial risk (trained NIC 1.52 [1.16 -1.99], nurses-to-infant ratio 1.81 [1.40-2.33]). Although public centers showed higher risk of morbidity and mortality compared with private centers, differences were statistically not significant.
Conclusions: In this population neonatal outcomes were associated with levels of patient volume and training of medical and nursing staff. No differences were observed between public and private centers.