Effectiveness of Quality Improvement Strategies in Preventing Healthcare-Associated Infections Among Neurosurgical Patients Admitted to Intensive Care Units: A Systematic Review.

Background: Healthcare-associated infections (HAIs) remain a major and largely preventable cause of morbidity, excess mortality, prolonged hospitalization, and escalating healthcare costs in intensive care units (ICUs) worldwide. Neurosurgical patients are particularly vulnerable because of frequent exposure to invasive devices such as external ventricular drains (EVDs), central venous catheters, urinary catheters, and mechanical ventilation, combined with impaired neurological status and prolonged ICU stays. Although quality improvement (QI) strategies have been widely implemented across critical care settings, evidence specific to neurosurgical and neurocritical care populations remains fragmented. Objectives: To systematically evaluate the effectiveness of QI interventions in reducing HAI incidence among neurosurgical and neurological ICU patients and to assess their impact on secondary outcomes including ICU length of stay, device utilization, and bundle compliance. Methods: A comprehensive search was conducted across PubMed/MEDLINE, Scopus, Embase, the Cochrane Library, and Web of Science from January 2010 to May 2026, following PRISMA 2020 guidelines. Eligible studies for the primary evidence synthesis included randomized controlled trials, quasi-experimental studies, and observational cohort studies evaluating structured QI interventions for HAI prevention in neurosurgical or neurological ICU populations, or mixed ICU settings with extractable neurocritical care data. Systematic reviews identified during screening were retained for contextual interpretation and reference screening but were excluded from the primary evidence synthesis to avoid duplication of overlapping primary data. Risk of bias was assessed using ROBINS-I, Cochrane RoB 2, and the Newcastle-Ottawa Scale according to study design. Results: Seventeen primary studies from 14 countries met eligibility criteria and were included in the primary narrative synthesis. Three systematic reviews were retained for contextual interpretation. Structured QI interventions consistently reduced device-associated infection rates across studies. The strongest evidence was observed for EVD-specific care bundles, with EVD-related infection rates decreasing from 14.35 to 3.21 per 1,000 catheter-days following bundle implementation, and one study reporting 20 consecutive infection-free months after interprofessional bundle adoption. Device-associated infection prevention bundles also demonstrated clinically meaningful reductions, including VAP rates decreasing from 68.2 to 47.4 per 1,000 ventilator-days and CAUTI rates from 24.9 to 13.4 per 1,000 catheter-days following structured educational interventions. CLABSI rates declined substantially following standardized central venous catheter bundle implementation, reaching zero in one study with sustained monitoring. Risk of bias was predominantly low to moderate across included primary studies. Conclusions: Structured QI interventions, particularly EVD-specific care bundles, device-associated infection prevention protocols, and staff education programs with compliance monitoring, consistently reduce HAI incidence in neurosurgical and neurological ICU settings. Although the evidence base is predominantly non-randomized, findings are directionally consistent across diverse healthcare systems and institutional contexts. Universal adoption of evidence-based infection prevention frameworks in neurocritical care is strongly supported.