Implementation
RECRUITMENT, GLOMERULONEPHRITIS
Biopsy proved 59 cases with AIN of unknown aetiology were eligible for the trial from 70 clinically suspected cases. Eleven cases were excluded after biopsy due to eight insufficient kidney tissues for reporting, one normal kidney tissue and two glomerulonephritis. Patients were followed-up monthly at the outpatient clinic until the completion of their allocated 3 months treatments. Prednisolone was discontinued due to gastric side effects in 2 patients (group A), and 3 others (2 from group B and 1 from group C) were lost to follow-up after treatment allocation. At the end of 6 months, 54 patients (92%) completed the allocated treatments, and at the end of 36 months, 45 patients (76%) had completed their allocated treatments and were retained for follow-up of outcome (Fig. Sample size of 50 cases for each arm was calculated on the assumptions of α = 0.05; power = 0.8, and 20% effect size (to achieve a 20% reduction from 144 (± 52) µmol/L mean serum creatinine). This mean creatinine value was calculated when designing the study, from the serum creatinine values of diagnosed AIN patients in the endemic regions, recorded in the biopsy request forms. We added about 15% loss to follow-up in a trial, for a sample size of 230. However, the broad inclusion criteria of the study failed to bring the required sample size and a meaningful effect to this study at 6 months of assessment. Based on the factorial design, prednisolone-treated patients (arms A + C) and no prednisolone-treated (arms B + D) were merged for an exploratory analysis to assess the outcome by 6–36 months from recruitment which was not prespecified (Fig. 