Table 1. Quality assessment of a selection of 430 randomized controlled trials (RCT) in nephrology, dialysis, and transplantation

Quality ItemRandom Sample (n = 160) % (95% CI)Diabetic Nephropathy Prevention (n = 156) % (95% CI)Primary and Secondary Glomerulonephritisa (n = 37) % (95% CI)Hemoglobin Targets Adequacy (n = 16) % (95% CI)Transplantb (n = 61) % (95% CI)Total (n = 430) % (95% CI)P Valuec
a Including ten trials from an ongoing Cochrane systematic review on immunosuppressive and non-immunosuppressive agents for IgA nephropathy and 27 trials from an ongoing Cochrane systematic review on treatment for lupus nephritis.
b Including 32 trials from an ongoing Cochrane systematic review on tacrolimus versus cyclosporin for renal transplant recipients and 29 trials from an ongoing Cochrane systematic review on interleukin-2 for renal transplant recipients.
c χ2 test for difference in proportions, 8 degrees of freedom.
d Excluding trials where assessment of number of patients lost to follow-up was not possible or unclear.
Allocation concealment
    adequate4.3 (1.7 to 8.8)7.7 (3.5 to 11.9)7.9 (1.6 to 21.3)0.0 (0.0 to 20.5)16.4 (8.1 to 28.0)7.4 (4.9 to 9.8)0.07
    unclear92.6 (87.2 to 96.0)89.7 (84.9 to 94.4)84.3 (68.7 to 93.9)100.0 (79.4 to 100.0)80.4 (68.1 to 89.4)89.4 (86.4 to 92.2)
    inadequate3.1 (1.0 to 7.1)2.6 (0.1 to 5.1)7.8 (1.6 to 21.3)0.0 (0.0 to 20.5)3.2 (0.0 to 11.3)3.2 (1.5 to 4.9)
Blinding
    participants37.5 (29.9 to 45.4)60.2 (52.5 to 67.8)18.4 (7.7 to 14.3)43.7 (19.7 to 70.1)27.8 (17.1 to 40.8)43.0 (38.3 to 47.7)<0.05
    investigators32.5 (25.3 to 40.3)52.5 (44.6 to 60.3)13.1 (4.4 to 28.0)25.0 (7.2 to 5.2)14.7 (6.9 to 26.1)35.3 (30.8 to 39.9)
    outcome assessors1.8 (0.3 to 5.3)12.1 (6.9 to 17.2)2.6 (0.6 to 13.8)0.0 (0.0 to 20.5)14.7 (6.9 to 26.1)7.4 (4.9 to 9.9)
Intention-to-treat
    yes33.7 (26.4 to 41.6)25.1 (18.3 to 31.9)42.1 (26.3 to 59.1)12.5 (1.5 to 38.3)26.3 (15.7 to 39.0)29.7 (25.1 to 33.8)<0.01
    no53.2 (45.0 to 61.0)58.3 (44.6 to 60.3)44.8 (28.6 to 61.6)87.5 (61.6 to 98.4)19.7 (10.5 to 31.8)51.0 (46.1 to 55.6)
    unclear13.1 (8.3 to 19.3)16.6 (10.7 to 22.4)13.1 (4.4 to 28.0)0.0 (0.0 to 20.5)54.0 (40.8 to 66.9)19.3 (15.3 to 22.7)
Lost to follow-up (%)d
    0–2086.8 (81.5 to 92.0)85.5 (79.9 to 91.0)92.1 (78.6 to 98.3)68.7 (41.3 to 88.9)100 (94.1 to 100.0)86.7 (74.7 to 89.5)0.28
    20–409.5 (5.3 to 14.9)12.4 (7.2 to 17.5)5.3 (0.6 to 17.7)25.1 (7.2 to 52.3)0.0 (0.0 to 5.78)10.2 (6.5 to 12.0)
    >403.7 (1.4 to 8.0)2.1 (1.1 to 8.2)2.6 (0.0 to 13.8)6.2 (0.1 to 30.2)0.0 (0.0 to 5.78)3.1 (0.9 to 3.7)