Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013.

BACKGROUND

Late-onset sepsis (LOS) is a life-threatening complication in preterm infants, with reported incidence rates of 1%-30% that vary by clinical and geographical factors. Quality improvement (QI) bundles integrating infection control, nutrition, and device management show promise in reducing LOS, but evidence remains fragmented due to heterogeneous definitions and mixed study populations.

METHODS

A systematic review and meta-analysis of QI studies was conducted across PubMed, Embase, Cochrane Library, and Web of Science (inception to March 19th, 2025). Studies were included if they reported pre-post QI outcomes for LOS in preterm infants (gestational age < 37 weeks), with effect sizes synthesized as odds ratios (ORs) and 95% confidence intervals (CIs). Heterogeneity was evaluated using I 2, with random-effects models for I 2 ≥ 50%. Subgroup analyses explored LOS definition impacts (time windows: ≥48 h, ≥72 h, other) and meta-regression tested covariates (study year, sample size, quality).

RESULTS

Of 9,705 identified studies, 29 (21 for meta-analysis, n = 29,120 infants) met criteria. QI bundles significantly reduced LOS in very low birth weight (VLBW) infants (pooled OR = 0.47, 95% CI [0.38-0.58], I 2 = 88.7%) and extremely low birth weight (ELBW) infants (OR = 0.49, 95% CI [0.29-0.83], I 2 = 80.6%). Core components included multidisciplinary teams (25/29), hand hygiene (21/29), and central line management (22/29). Subgroup analysis showed varying effects by LOS definition: OR = 0.35 (95% CI [0.19-0.64]) for ≥ 48 h, OR = 0.50 (95% CI [0.39-0.64]) for ≥ 72 h, and OR = 0.71 (95% CI [0.61-0.82]) for ill-defined thresholds. Meta-regression identified no significant modifiers (all p > 0.0), but publication bias was detected in VLBW analyses (Egger's test, p < 0.0).

CONCLUSION

QI bundles significantly reduce LOS in preterm infants, including VLBW and ELBW subgroups, through core components like multidisciplinary teams, hand hygiene, and central line management. Given outcome variations by diagnostic criteria, standardizing LOS definitions is crucial. These bundles should be integrated into routine care globally. Future efforts should prioritize standardized reporting, antibiotic stewardship, and equitable implementation, especially in low-resource settings, by building on existing evidence and broader healthcare principles.