Eighty trials (51,099 participants) were included. Most studies were unclear in their reporting of randomisation and allocation concealment methods. Around one third of studies were at high risk of bias with respect to blinding, intention-to-treat analyses and reporting of incomplete outcome data. More than half of the studies were at risk of bias due to other threats to validity. Around three-quarters of the studies were at high risk of bias due to selective outcome reporting. Two studies had a low risk of bias for all assessments. Follow-up ranged from two months to 5.5 years.
Moderate to high quality evidence suggested statins reduced all-cause mortality (RR 0.81, 95% CI 0.74 to 0.88; 11 studies, Ι²=32%), cardiovascular mortality (RR 0.78, 95% CI 0.68 to 0.89; eight studies, Ι²=0%) and major cardiovascular events (RR 0.76, 95% CI 0.73 to 0.80; 14 studies, Ι²=30%) in participants who did not receive dialysis. There was an indication that publication bias affected the major cardiovascular events analysis.
Moderate to high quality evidence indicated that statins had no statistically significant effects on all-cause mortality, cardiovascular mortality and major cardiovascular events in participants who received dialysis. There was no evidence of heterogeneity.
Low quality evidence suggested uncertain effects of statins in kidney transplant recipients.
Meta-regression analyses for all-cause mortality suggested that heterogeneity was related to disease stage, statin type, estimated glomerular filtration rate, baseline cholesterol and the proportion of patients with diabetes.
Statins had little or no effect on cancer, myalgia, abnormal liver function or withdrawal from treatment (adverse effects were evaluated in fewer than half of the trials).
Further results were reported.