Repositioning to Prevent Bedsores: What 11 Trials and 4,462 Patients Actually Show

Pressure injuries — localized skin and tissue damage over bony prominences caused by prolonged pressure or shear — represent a serious, costly, and largely preventable complication for hospitalized and long-term care patients. Immobility, malnutrition, and reduced sensation are key risk factors. Regular repositioning is a cornerstone of prevention, yet the optimal frequency, angle, and technique have never been firmly established. This 2026 Cochrane update, the second since the original 2014 review, synthesizes the best available evidence to guide clinical practice.

Researchers searched five major databases through May 2025 and identified 11 eligible randomized controlled trials totaling 4,462 participants aged 18–90 years. Settings included ICUs, operating theatres, acute wards, and nursing homes across China, Belgium, North America, Iran, and the UK. Three trials were new additions since the 2020 update. The primary outcome was cumulative incidence of any new pressure injury; secondary outcomes included quality of life, pain, patient satisfaction, and costs. Risk of bias was assessed using Cochrane's RoB 2 tool and evidence certainty graded using GRADE methodology.

For repositioning frequency, pooling four trials (1,104 participants) comparing 2- versus 4-hourly turning yielded a risk ratio of 1.05 (95% CI 0.79–1.39) — no meaningful difference — rated very low certainty. Comparisons of 2- vs. 3-hourly (RR 1.10, 95% CI 0.30–4.08; 3 trials, 795 participants), 3- vs. 4-hourly (RR 0.99, 95% CI 0.22–4.43; 3 trials, 776 participants), and 4- vs. 6-hourly (RR 0.73, 95% CI 0.53–1.02; 1 trial, 129 participants) were similarly inconclusive. A standout finding came from a 1,226-patient ICU trial testing wearable patient position sensors: nurses receiving real-time visual reminders to reposition every 2 hours achieved a 72% relative reduction in pressure injuries (RR 0.28, 95% CI 0.10–0.75), rated moderate certainty — the strongest signal in the review.

On positioning angle, pooling two trials (252 participants) comparing 30° lateral tilt with 3-hourly turning versus 90° tilt with 6-hourly turning found RR 0.62 (95% CI 0.10–3.97), rated very low certainty. A three-arm ICU trial (120 participants) comparing 30° and 45° head-of-bed elevation reported zero pressure injuries in both arms. Crucially, one 116-patient ICU trial found that prone positioning (used with lung recruitment maneuvers) was associated with substantially higher pressure injury incidence compared to supine (RR 4.55, 95% CI 2.31–8.98), rated low certainty — a clinically important signal for critical care teams managing prone-ventilated COVID-19 or ARDS patients.

Two trials examined micromovement devices in operating rooms (477 participants combined), finding a significant reduction in pressure injuries (RR 0.28, 95% CI 0.11–0.67), though rated low certainty due to few events. On cost-effectiveness, two nursing home economic analyses found that 3- or 4-hourly turning cost CAD $11.05–$16.74 less per resident per day versus 2-hourly, mainly through reduced nursing time. A separate study found 3-hourly 30° tilt cost EUR 46.50 less per patient than standard 6-hourly 90° rotation, projecting annual savings of EUR 512,800. No trials reported quality of life, procedural pain, or patient satisfaction outcomes.

The overarching conclusion is sobering: despite repositioning being a universal, resource-intensive standard of care, the evidence base remains thin and largely very low certainty. Clinical decisions about turning frequency should therefore be individualized based on patient risk profile, mobility, comfort, and clinical condition rather than rigid protocol. The sensor-guided reminder system stands out as the one intervention with moderate-certainty benefit, suggesting that adherence technology — not just schedule choice — may be the key lever.