Ethnic Differences in Incidence and Outcomes of Childhood... : Clinical Journal of the American Society of Nephrology (original) (raw)

Original Articles: Clinical Nephrology

Ethnic Differences in Incidence and Outcomes of Childhood Nephrotic Syndrome

Banh, Tonny H.M.*; Hussain-Shamsy, Neesha*; Patel, Viral*; Vasilevska-Ristovska, Jovanka*; Borges, Karlota*; Sibbald, Cathryn*; Lipszyc, Deborah*; Brooke, Josefina; Geary, Denis; Langlois, Valerie; Reddon, Michele; Pearl, Rachel; Levin, Leo; Piekut, Monica; Licht, Christoph P.B.; Radhakrishnan, Seetha; Aitken-Menezes, Kimberly; Harvey, Elizabeth; Hebert, Diane; Piscione, Tino D.; Parekh, Rulan S.*

*Child Health Evaluative Sciences, Research Institute,

†Division of Nephrology, and

§Program in Cell Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada;

‡University of Toronto, Toronto, Ontario, Canada;

‖University Health Network, Toronto, Ontario, Canada; and

¶Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada

T.H.M.B. and N.H.-S. contributed equally to this work.

Correspondence: Dr. Rulan S. Parekh, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8. Email: [email protected]

Abstract

Background and objectives

Ethnic differences in outcomes among children with nephrotic syndrome are unknown.

Design, setting, participants, & measurements

We conducted a longitudinal study at a single regional pediatric center comparing ethnic differences in incidence from 2001 to 2011 census data and longitudinal outcomes, including relapse rates, time to first relapse, frequently relapsing disease, and use of cyclophosphamide. Among 711 children, 24% were European, 33% were South Asian, 10% were East/Southeast Asian, and 33% were of other origins.

Results

Over 10 years, the overall incidence increased from 1.99/100,000 to 4.71/100,000 among children ages 1–18 years old. In 2011, South Asians had a higher incidence rate ratio of 6.61 (95% confidence interval, 3.16 to 15.1) compared with Europeans. East/Southeast Asians had a similar incidence rate ratio (0.76; 95% confidence interval, 0.13 to 2.94) to Europeans. We determined outcomes in 455 children from the three largest ethnic groups with steroid-sensitive disease over a median of 4 years. South Asian and East/Southeast Asian children had significantly lower odds of frequently relapsing disease at 12 months (South Asian: adjusted odds ratio; 0.55; 95% confidence interval, 0.39 to 0.77; East/Southeast Asian: adjusted odds ratio; 0.42; 95% confidence interval, 0.34 to 0.51), fewer subsequent relapses (South Asian: adjusted odds ratio; 0.64; 95% confidence interval, 0.50 to 0.81; East/Southeast Asian: adjusted odds ratio; 0.47; 95% confidence interval, 0.24 to 0.91), lower risk of a first relapse (South Asian: adjusted hazard ratio, 0.74; 95% confidence interval, 0.67 to 0.83; East/Southeast Asian: adjusted hazard ratio, 0.65; 95% CI, 0.63 to 0.68), and lower use of cyclophosphamide (South Asian: adjusted hazard ratio, 0.82; 95% confidence interval, 0.53 to 1.28; East/Southeast Asian: adjusted hazard ratio, 0.54; 95% confidence interval, 0.41 to 0.71) compared with European children.

Conclusions

Despite the higher incidence among South Asians, South and East/Southeast Asian children have significantly less complicated clinical outcomes compared with Europeans.