Treatment patterns in patients with systemic lupus erythematosus in New Zealand.

Objectives: This study aims to explore the treatment pattern of systemic lupus erythematosus (SLE) in Aotearoa/New Zealand.

Methods: SLE patients were linked to the pharmaceutical dispensing data. The use of publicly funded anti-malarials, immunomodulators, biologics, glucocorticoids and bisphosphonates were compared by gender, ethnicity, age group, socioeconomic status and year of SLE identification. Adherence to hydroxychloroquine was examined using the medication possession ratio (MPR), with a MPR of ≥0.8 considered as high adherence.

Results: Of the 2631 SLE patients, 73.8% used hydroxychloroquine, 64.1% used immunomodulators/biologics and 68.0% used 5 mg or more prednisone daily for at least 90 days. Women were more likely to use hydroxychloroquine than men. Asian patients had a different treatment pattern than other ethnic groups, and Māori were less likely to use hydroxychloroquine. The proportions of patients using different treatments decreased with age. Of the patients using hydroxychloroquine, 54.5% had high adherence. For patients over 40 years old and on long term prednisone, 47.3% had bisphosphonates and this figure was 17.8% for patients under the age of 40 years old. Patients with better socioeconomic status had a higher probability of using bisphosphonates than patients with lower socioeconomic status.

Conclusions: Adherence to hydroxychloroquine in these patients varied and was lower in men and in Māori. Prednisone is commonly prescribed and used long term. Half of those over the age of 40 years old co-administered bisphosphonate. Further research is needed to identify the reasons for these discrepancies on SLE treatments by gender, ethnicity, age and socioeconomic status.