Daily practices regarding safety monitoring of low-dose methotrexate and comparison to guidelines: A population-based cohort study

Psoriasis/Psoriatic Arthritis Patients' Long-term Treatment Patterns and Adherence to Systemic Treatments Monitoring Recommendations

Limited information exists regarding treatment of patients with psoriasis/psoriatic arthritis in primary care. The aim of this study is to assess treatment patterns, adherence, persistence, and compliance in newly diagnosed patients with psoriasis/psoriatic arthritis from 2012 to 2018 in Stockholm, Sweden. In addition, laboratory monitoring before initiation of treatment and at recommended intervals was quantified for patients prescribed methotrexate or biologics. A total of 51,639 individuals were included, with 39% initiating treatment with topical corticosteroids and < 5% receiving systemic treatment within 6 months post-diagnosis. During a median (interquartile range) follow-up of 7 (4-8) years, 18% of patients received systemic treatments at some point. Overall, 5-year persistence rates were 32%, 45% and 19% for methotrexate, biologics, and other systemic treatments, respectively. Pre-initiation laboratory tests, as recommended by guidelines, were performed in approximately 70% and 62% of methotrexate and biologics users, respectively. Follow-up monitoring at recommended time intervals occurred in 14-20% and 31-33% of patients prescribed methotrexate and biologics, respectively. These findings highlight gaps in the pharmacological care of patients with psoriasis/psoriatic arthritis, including suboptimal adherence/persistence and inadequate laboratory monitoring.

[Patient safety in the treatment of rheumatic diseases : Laboratory monitoring in methotrexate treatment]

BACKGROUND

Methotrexate (MTX) is the most commonly prescribed disease-modifying drug in the treatment of rheumatic diseases. Regular laboratory testing is recommended to recognize side effects, such as hepatotoxicity and myelotoxicity as well as decreases in renal function that may cause toxic MTX accumulation. Additionally, folic acid is recommended as prophylaxis against specific side effects. In this study we investigated whether laboratory monitoring and prescription of folic acid took place according to published recommendations.

MATERIAL AND METHODS

Claims data from the statutory health insurance from 1 January 2009 to 31 December 2013 were retrospectively analyzed. A total of 40,087 adults with a rheumatic diagnosis (ICD10 codes M05-M18), no malignant disease and no previous MTX prescription within 12 months were extracted from the InGef (Institute for Applied Health Research in Berlin, formerly Health Risk Institute) research database. The frequency of recommended laboratory testing, appointments with rheumatologists and the prescription of folic acid prophylaxis were investigated.

RESULTS

Of the patients 12,451 began treatment with MTX in the observation period. Between 42% and 46% of recommended blood counts, liver values and kidney function tests and 14% of urinalyses were performed according to recommendations. Of the patients 84% were seen regularly by a rheumatologist and 74% received a prescription for prophylactic folic acid. Serious conditions potentially resulting from MTX treatment were observed in 0.7-3.5 cases/1000 person years.

DISCUSSION

Laboratory monitoring in the context of MTX treatment is carried out less frequently than recommended in the literature. Potential MTX-associated serious complications are rare from a practice perspective. On the one hand solutions are needed for a better coordination of laboratory monitoring. On the other hand more empirical evidence is needed regarding the benefits of laboratory monitoring and the appropriate intervals thereof.