Relationship Between Nurse Staffing Levels and Hospital-Acquired Pressure Injury Rates in Nigerian Tertiary Hospitals: A Multi-Site Study

Background: Hospital-acquired pressure injuries are internationally recognised nursing-sensitive outcomes. Despite their clinical and financial significance, the relationship between nurse staffing and pressure injury rates in Nigerian tertiary hospitals has not been empirically established. Aim: This study examined the relationship between nurse staffing levels and hospital-acquired pressure injury rates at four selected tertiary hospitals in Nigeria. Methods: A retrospective correlational design reviewed administrative staffing records and pressure injury incidence data from four teaching hospitals spanning the South West, South East, North Central, and North West geopolitical zones over a 24-month period. Spearman's rank correlation and multilevel regression were applied. Results: Mean nurse-to-patient ratios ranged from 1:8 to 1:14 across study sites. A strong negative correlation was found between staffing adequacy and pressure injury incidence (r = -0.67, p < 0.001). Each additional patient per nurse was associated with a 12% increase in injury incidence. Conclusion: Nurse staffing inadequacy is a significant systemic determinant of pressure injury incidence in Nigerian hospitals. The study provides empirical grounding for minimum nurse staffing ratio legislation and targeted investment in nursing workforce expansion. Keywords: nurse staffing, pressure injuries, nursing-sensitive outcomes, tertiary hospitals, Nigeria.