Practice variation in the use of steroid-sparing therapies in childhood steroid-sensitive nephrotic syndrome: results from a prospective cohort study

BackgroundSteroid-sparing therapies are often used to prolong disease remission while minimizing steroid toxicity in childhood steroid-sensitive nephrotic syndrome (SSNS). This study aims to describe practice variation in the use of steroid-sparing medications for childhood SSNS in Canada.MethodsChildren (1–18 years) with nephrotic syndrome (NS) from eleven pediatric nephrology centers in Canada were enrolled in the Canadian Childhood Nephrotic Syndrome (CHILDNEPH) prospective cohort from 2013–2019. Data, including time to first relapse for children treated with cyclophosphamide, tacrolimus, mycophenolate mofetil, cyclosporine and rituximab were analyzed using summary statistics. Participants who received steroid-sparing therapies prior to enrolment were excluded.ResultsOf the 371 children enrolled, 321 (86.5%) had SSNS and 133 met the study criteria. Median age at enrollment was 3.0 years (IQR: 2.0–6.3). Median follow-up period was 3.0 years (IQR 1.0–4.0). Timing of initiation and choice of steroid-sparing therapy varied across centers. The majority (72.2%) initiated therapies after a median of 3 relapses (IQR: 2-4). Cyclophosphamide and tacrolimus were the most frequently used initial therapies at 39.1% and 23.3%, respectively. Thirty (22.6%) patients switched to a second medication after a median time of 4 months (IQR 0.25–11); of which, 40% switched from either cyclophosphamide or mycophenolate mofetil to tacrolimus. There were no statistically significant differences in time to first relapse with initial therapies (log rank P-value 0.36).ConclusionsSignificant variation in the use of steroid-sparing therapies exists in the treatment of SSNS. A clinical trial is needed to examine the efficacy of these medications to optimize treatment and decrease practice variation.Graphical AbstractA higher resolution version of the Graphical abstract is available as Supplementary information