Table 3.

Association of ethnicity with frequently relapsing nephrotic syndrome, relapse rate, time to first relapse, and second–line medication use among 455 children with nephrotic syndrome (1993–2014)

Outcomes	European, n=160	South Asian, n=231	East/Southeast Asian, n=64
Frequently relapsing nephrotic  syndrome at 12 mo
Events, n	34	31	6
Odds ratio	Reference	0.57	0.38
95% Confidence interval	NA	0.38 to 0.88	0.38 to 0.39
P value	NA	0.01	0.001
Adjusted odds ratioa	Reference	0.55	0.42
95% Confidence interval	NA	0.39 to 0.77	0.34 to 0.51
P value	NA	0.001	0.001
Relapse rate per person-yearb
Relative risk	Reference	0.76	0.57
95% Confidence interval	NA	0.53 to 1.11	0.30 to 1.06
P value	NA	0.16	0.07
Adjusted relative riska	Reference	0.74	0.64
95% Confidence interval	NA	0.53 to 1.03	0.33 to 1.23
P value	NA	0.08	0.18
Developing first relapsec
Events, n	134	178	44
Hazard ratio	Reference	0.77	0.63
95% Confidence interval	NA	0.68 to 0.86	0.54 to 0.73
P value	NA	0.001	0.001
Adjusted hazard ratioa	Reference	0.74	0.65
95% Confidence interval	NA	0.67 to 0.83	0.63 to 0.68
P value	NA	0.001	0.001
Use of cyclophosphamide as  second-line medicationd
Events, n	60	74	13
Hazard ratio	Reference	0.82	0.55
95% Confidence interval	NA	0.51 to 1.32	0.51 to 0.59
P value	NA	0.42	0.001
Adjusted hazard ratioa	Reference	0.82	0.54
95% Confidence interval	NA	0.53 to 1.28	0.41 to 0.71
P value	NA	0.39	0.001

Analysis excluded children with initial steroid resistance during the initial course among these three ethnicities (n=24). NA, not applicable.

^aAdjusted for age at diagnosis and sex.

^bBy generalized linear model for log–transformed relapse rate.

^cBy Cox proportional hazards.

^dTruncated at 5 years of follow-up.