Volume 14 Supplement 3

Lupus 2012: New targets, new approaches

Open Access

Variation in renal biopsy and medication prescribing practices among pediatric Medicaid patients with lupus nephritis prior to end-stage renal disease in the US, 2000 to 2004

  • LT Hiraki1, 2,
  • CH Feldman2,
  • J Liu2,
  • GS Alarcón3,
  • MA Fischer2,
  • WC Winkelmayer4 and
  • KH Costenbader2
Arthritis Research & Therapy201214(Suppl 3):A58

DOI: 10.1186/ar3992

Published: 27 September 2012

Background

Unequal medical care may contribute to striking sociodemographic disparities seen in outcomes for children with lupus nephritis. Medicaid is the US federal-state program providing health insurance to low-income children and parents. We investigated US nationwide variation in renal biopsies and medication prescriptions for children with lupus nephritis enrolled in Medicaid, 2000 to 2004, in the months preceding end-stage renal disease (ESRD).

Methods

We identified all children aged 3 to <18 years with SLE (≥3 ICD-9 codes of 710.0, each >30 days apart) in the Medicaid Analytic eXtract (MAX) from 2000 to 2004, which contains outpatient and inpatient Medicaid claims for enrollees in 47 US states and the District of Columbia. These data were linked to the US Renal Data System, with information on essentially all ESRD patients in the US, for the same years. We compared frequencies of renal biopsies, and prescription of corticosteroids, hydroxychloroquine (HCQ) and immunosuppressants (mycophenylate mofetil (MMF), cyclophosphamide (CYC), cyclosporine, azathioprine (AZA), tacrolimus), across categories of sex, race/ethnicity, socioeconomic status (SES), US region of residence, residence in a designated Health Professional Shortage Area (HPSA), and quartiles of pediatric rheumatologist number in state of residence. We tested for differences across categories using chi-squared and Fisher's exact tests, and applied the Cochrane Armitage test for trend.

Results

Of the 254 pediatric lupus nephritis patients who developed ESRD, the mean age was 14.2 (± 2.4) years; 72% were female, 61% were African American and 19% were Hispanic. The mean time from first SLE claim to ESRD was 3.8 (± 2.1) years. A total of 46% had at least one renal biopsy preceding ESRD. More children in the lower quartiles of SES and the higher quartiles of rheumatologist number per state, received a biopsy (P trend < 0.05) (Table 1). Ninety-one percent of children were prescribed steroids at some time preceding ESRD, 63% were prescribed HCQ and 66% any other immunosuppressant, 50% of whom were prescribed MMF, 30% AZA and 14% CYC. We observed variation in prescribed steroids across region of residence, HCQ and immunosuppressant across race (more non-White patients prescribed both medications), and a greater proportion of patients prescribed HCQ in states with a higher number of rheumatologists per state.
Table 1

Proportion of pediatric patients with lupus nephritis-associated ESRD who received renal biopsies and medications prior to ESRD

  

Renal biopsy

Corticosteroids

HCQ

Immunosuppressants

  

n (%)

P valuea

n (%)

P valuea

n (%)

P valuea

n (%)

P valuea

Total

254

        

Sex

         

   Female

182

89 (49)

0.15

167 (92)

0.47

117 (64)

0.38

121 (66)

0.85

   Male

72

28 (39)

 

64 (89)

 

42 (58)

 

47 (65)

 

Race/ethnicity

         

   White

25

14 (56)

0.52

22 (88)

0.19

11 (44)

1 × 106

13 (52)

0.02

   Black

155

74 (48)

 

139 (90)

 

91 (59)

 

103 (66)

 

   Hispanic

48

21 (44)

 

47 (98)

 

44 (92)

 

34 (71)

 

   Asian

17

-

 

16 (94)

 

-

 

15 (88)

 

   Native

-

-

 

-

 

-

 

-

 

SES group

         

   Quartile 1 - lowest

63

37 (59)

0.02b

60 (95)

0.21b

36 (57)

0.33b

42 (67)

0.95b

   Quartile 2

63

27 (43)

 

56 (89)

 

41 (65)

 

42 (67)

 

   Quartile 3

63

29 (46)

 

58 (92)

 

39 (62)

 

42 (67)

 

   Quartile 4 - highest

64

23 (36)

 

56 (88)

 

43 (67)

 

42 (66)

 

Region of residence

         

   Northeast

35

10 (29)

0.09

30 (86)

0.004

22 (63)

0.01

30 (58)

0.53

   Midwest

52

26 (50)

 

43 (83)

 

23 (44)

 

23 (66)

 

   South

123

63 (51)

 

120 (98)

 

81 (66)

 

85 (69)

 

   West

44

18 (41)

 

38 (86)

 

33 (75)

 

30 (68)

 

Residence in health professional shortage area

         

   Not HPSA

13

-

0.78

13 (100)

0.48

-

0.09

11 (85)

0.12

   HPSA

240

110 (46)

 

217 (90)

 

151 (63)

 

157 (65)

 

Pediatric rheumatologist per state

         

   Quartile 1 - lowest

63

38 (60)

0.0002b

59 (94)

0.24b

35 (56)

0.02b

43 (68)

0.50b

   Quartile 2

64

34 (53)

 

62 (97)

 

37 (58)

 

46 (72)

 

   Quartile 3

72

30 (42)

 

63 (88)

 

46 (64)

 

42 (58)

 

   Quartile 4 - highest

55

15 (27)

 

47 (85)

 

41 (75)

 

37 (67)

 

-, cell sizes under 11 have been suppressed in accordance with Centers for Medicare and Medicaid Services policy to protect privacy. aP value for chi-square tests and Fisher's exact tests for small cell counts. bP value for Cochran-Armitage Trend tests.

Conclusion

We observed significant differences in the proportion of children who had received renal biopsies across categories of SES and rheumatologist number per state, as well as marked differences in medication prescribing across categories race, SES, regions of residence and rheumatologist number in state of residence.

Authors’ Affiliations

(1)
Harvard School of Public Health
(2)
Brigham and Women's Hospital
(3)
University of Alabama at Birmingham
(4)
Stanford University School of Medicine

Copyright

© Hiraki et al.; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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