Thirty-three prospective studies (n=5,529) were included. Eleven studies evaluated SAP: 10 RCTs and one prospective intervention study with a historical control group. Twenty-two studies evaluated SDD: 19 RCTs, 2 prospective cohort studies and one non-randomised study with a placebo control group.
The median Jadad quality score for RCTs was 3.5. Twenty-RCTs described the method of randomisation and 15 RCTs were double-blind.
The risk of yeast colonisation was statistically significantly reduced with SAP (OR 0.38, 95% CI: 0.20, 0.70; NNT 5; 5 studies; fail-safe N 25) and SDD (OR 0.12, 95% CI: 0.05, 0.29; NNT 3; 10 studies; fail-safe N 194) compared with controls. Significant heterogeneity was found amongst studies of SDD (p<0.001, I2=73.5%) but not amongst those of SAP (p=0.10). The treatment effect was significantly greater with SDD than with SAP (OR 3.62, 95% CI: 1.12, 11.77). Fail-safe N values were 25 for SAP and 194 for SDD.
The risk of invasive infection was statistically significantly reduced with SAP (OR 0.54, 95% CI: 0.39, 0.75; NNT 20; 10 studies; fail-safe N 26) and SDD (OR 0.29, 95% CI: 0.18, 0.45; NNT 18; 15 studies; fail-safe N 101) compared with controls. No significant heterogeneity was found for either analysis (p=0.40 and p=0.45). The treatment effect was significantly greater with SDD than with SAP (OR 2.0, 95% CI: 1.1, 3.7). Fail-safe N values for yeast infection were 26 for SAP and 101 for SDD.
The risk of candidaemia was statistically significantly reduced with SAP (OR 0.32, 95% CI: 0.12, 0.82; NNT 38; 6 studies), but not with SDD (OR 0.59, 95% CI: 0.25, 1.40; 12 studies), compared with control. No significant heterogeneity was found for either analysis (p=0.25 and p=0.71). There was no significant difference between ORs for SAP and SDD (p=0.34). The fail-safe N was 25 for SAP.
All-cause mortality was reduced with SAP (OR 0.80, 95% CI: 0.64, 1.00; 11 studies) and significantly reduced with SDD (OR 0.73, 95% CI: 0.59, 0.93; NNT 15; 21 studies) compared with controls. No significant heterogeneity was found for either analysis (p=0.61 and p=0.10). There was no significant difference between the ORs for SAP and SDD (p=0.58). The fail-safe N was 41 for SDD.
Mortality directly attributable to yeast infection was significantly reduced with antifungal prophylaxis (OR 0.23, 95% CI: 0.09, 0.60; NNT 41; 6 studies).