The number of included studies was unclear. It appeared that three studies evaluated clinical effectiveness (n=528); one controlled clinical trial (n=124); two before and after studies (n=404). Approximately 30 studies were RAS validation studies (n=15,525).
One study found a significant increase in pressure reducing mattress provision (p<0.00001) and significant decrease in PU incidence (p<0.0001) in the RAS group compared to control. Another study found significantly higher number of preventions and more precocious interventions in the RAS group compared to control. One study found no difference in PU prevalence between the RAS group and control.
The Braden Scale was a significant predictor of PU risk (16 studies, n=5847) OR 4.08 (95% CI: 2.56, 6.48), as was the Norton scale (five studies, n=2008) OR 2.16 (95% CI: 1.03, 4.54) and Waterlow scale (five studies, n=2215) OR 2.05 (95% CI: 1.11, 3.76). Clinical judgement (three studies, n=302) was not a significant predictor of PU.
The Braden Scale achieved the best validity indicator scores (20 studies), while the Norton Scale (five studies) and the Waterlow Scale (six studies) were comparable to nurses' clinical judgement (three studies). The Waterlow Scale had high sensitivity (82.5%) but low specificity (27.4%).