Volume 16 Supplement 1

Lupus 2014: New Targets, New Approaches

Open Access

Cluster analysis of longitudinal treatment patterns in patients newly diagnosed with systemic lupus erythematosus in the United States

  • Hong Kan1Email author,
  • Saurabh Nagar1,
  • Jeetvan Patel1,
  • Daniel J Wallace2 and
  • Charles Molta3
Arthritis Research & Therapy201416(Suppl 1):A52

https://doi.org/10.1186/ar4668

Published: 18 September 2014

Background

Treatments for systemic lupus erythematosus (SLE) include corticosteroids (CS), antimalarials, nonsteroidal anti-inflammatory drugs, cytotoxic agents, and immunosuppressive/immunomodulatory agents. We examined treatment patterns in newly diagnosed SLE patients from a multipayer US claims database.

Methods

This study (GSK HO-13-13054) retrospectively followed incident SLE patients' treatment for 4 years in the MarketScan commercial claims database. The earliest medical claim date with SLE diagnosis (ICD-9 code 710.0x; 1 January 2002 to 31 March 2008) was the index date. Patients were ≥18 years at index, had continuous medical and pharmacy benefits for 12 months pre index without SLE diagnosis and 48 months post index, with ≥1 SLE-related inpatient claim or ≥2 office or emergency room visits with SLE diagnosis ≥30 days apart within 12 months post index. A specialist must have made ≥1 SLE diagnosis at index or within 12 months post index. Results were stratified by provider type (primary care physician (PCP)/specialist). A disjoint k-means cluster analysis identified treatment pathways using annual prescription numbers for CS, hydroxychloroquine (HCQ), mycophenolate mofetil, azathioprine, and methotrexate as input variables.

Results

The study identified 2,086 newly diagnosed SLE patients (mean age: 47.2 years; female: 91%). In the 4 years post index, 1,031 (49.4%) patients were not actively treated (<0.05 prescriptions/year). Of the 219 (10.5%) patients who primarily received CS, 42 had persistently high numbers of prescriptions (~1/month), and 177 received 4.9 (mean) prescriptions in Year 1, decreasing in Years 2 to 4. Three subgroups emerged within the 606 (29.1%) patients who primarily received HCQ: persistent high number of prescriptions (~1/month), persistent moderate number of prescriptions (3.2 to 4.1/year), and poor adherence (Year 1, 8.7 prescriptions; Years 2 to 4, decreasing prescriptions). Both CS and HCQ were received by 138 (6.6%) patients; 56 had high numbers of prescriptions (Years 1 to 4); 82 showed progressively decreasing prescriptions. Fifty-four (2.6%) and 38 (1.8%) patients had moderate numbers of prescriptions for methotrexate (5.4 to 8.4/year) and azathioprine (5.7 to 7.5/year), respectively, with some CS and HCQ prescriptions. Treatment patterns differed in patients seen by specialists versus PCPs (P < 0.0001). Specialist-treated patients had a lower no-treatment rate than PCP-treated patients, and higher rates in active treatment clusters (Table 1).
Table 1

Longitudinal treatment patterns according to primary treatment by specialist or PCP

Cluster

Interpretation

Treated primarily by specialistsa

Treated primarily by PCPsa

  

n

%

n

%

1

Not actively treated throughout (<0.05 (mean) annual prescriptions)

216

26.2

815

64.6

2

CS only: high number of prescriptions (chronic use)

29

3.5

13

1.0

3

CS only: moderate number of prescriptions with slow reduction

85

10.3

92

7.3

4

HCQ only: high number of prescriptions (chronic use)

102

12.4

56

4.4

5

HCQ only: moderate number of prescriptions (chronic use)

136

16.5

134

10.6

6

HCQ only: poor adherence

111

13.5

67

5.3

7

CS plus HCQ: high number of prescriptions (chronic use)

32

3.9

24

1.9

8

CS plus HCQ: poor adherence

51

6.2

31

2.5

9

Methotrexate: moderate number of prescriptions plus some prescriptions for CS and HCQ

34

4.1

20

1.6

10

Azathioprine: moderate number of prescriptions plus some prescriptions for CS and HCQ

28

3.4

10

0.8

Total

 

824

100.0

1262

100.0

aPatients who visited a specialist (including a rheumatologist, dermatologist, nephrologist, ophthalmologist, or oncologist) in >50% of SLE-related office visits were defined as primarily seen by specialists. Patients who visited PCPs in >50% of SLE-related office visits were defined as primarily seen by PCPs. The difference in treatment patterns between the two groups was statistically significant (P < 0.0001).

Conclusions

Treatment patterns were observed among SLE patients using medical resources. In the 4 years post diagnosis: ~50% of patients were not actively treated; 50% received CS, HCQ, and immunosuppressants with differing combinations, intensities, and adherence levels. Specialists provided more intensive treatment than PCPs.

Declarations

Acknowledgements

Study and editorial support (Natasha Thomas, Fishawack Indicia Ltd) funded by GlaxoSmithKline.

Authors’ Affiliations

(1)
GlaxoSmithKline, Research Triangle Park
(2)
Cedars-Sinai Medical Center
(3)
GlaxoSmithKline, King of Prussia

Copyright

© Kan et al.; licensee BioMed Central Ltd. 2014

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/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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