Six RCTs were included in the review, including1,627 patients (based on text) or 1,634 patients (based on tables) (range 69 to 499). One RCT was double-blinded, two were single blinded and three were unblinded. All RCTs used intention-to-treat analysis. Duration of follow-up ranged from three to 18 months.
Mortality was significantly lower in the intervention group (HR 0.69, 95% CI 0.55 to 0.86; six RCTs), without significant heterogeneity (profiles test p=0.42). Sensitivity analyses did not change the significance of these findings. The effect of the intervention was stronger in patients younger than 75 years (two RCTs).
Other outcomes were unsuitable for meta-analysis. Generally rates of disease-specific hospitalisation appeared to be reduced by the intervention. The effect on all-case and non-cardiac hospitalisation was less clear (six RCTs). None of the trials reported an increase in adverse events associated with the intervention (four RCTs).