Discontinuation of anti-tumour necrosis factor alpha treatment owing to blood test abnormalities, and cost-effectiveness of alternate blood monitoring strategies

Abhishek, Abhishek; Stevenson, Matthew D; Nakafero, Georgina; Grainge, Matthew J; Evans, Ian; Alabas, Oras; Card, Tim; Taal, Maarten W; Aithal, Guruprasad P; Fox, Christopher P; Mallen, Christian D; van der Windt, Danielle A; Riley, Richard D; Warren, Richard B; Williams, Hywel C

Abstract

Background
There is no evidence base to support the use of 6-monthly monitoring blood tests for the early detection of liver, blood and renal toxicity during established anti-tumour necrosis factor alpha (TNFα) treatment.

Objectives
To evaluate the incidence and risk factors of anti-TNFα treatment cessation owing to liver, blood and renal side-effects, and to estimate the cost-effectiveness of alternate intervals between monitoring blood tests.

Methods
A secondary care-based retrospective cohort study was performed. Data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR) were used. Patients with at least moderate psoriasis prescribed their first anti-TNFα treatment were included. Treatment discontinuation due to a monitoring blood test abnormality was the primary outcome. Patients were followed-up from start of treatment to the outcome of interest, drug discontinuation, death, 31 July 2021 or up to 5 years, whichever came first. The incidence rate (IR) and 95% confidence intervals (CIs) of anti-TNFα discontinuation with monitoring blood test abnormality was calculated. Multivariate Cox regression was used to examine the association between risk factors and outcome. A mathematical model evaluated costs and quality-adjusted life years (QALYs) associated with increasing the length of time between monitoring blood tests during anti-TNFα treatment.

Results
The cohort included 8819 participants [3710 (42.1%) female, mean (SD) age 44.76 (13.20) years] that contributed 25 058 person-years (PY) of follow-up and experienced 125 treatment discontinuations owing to a monitoring blood test abnormality at an IR of 5.85 (95% CI 4.91–6.97)/1000 PY. Of these, 64 and 61 discontinuations occurred within the first year and after the first year of treatment start, at IRs of 8.62 (95% CI 6.74–11.01) and 3.44 (95% CI 2.67–4.42)/1000 PY, respectively. Increasing age (in years), diabetes and liver disease were associated with anti-TNFα discontinuation after a monitoring blood test abnormality [adjusted hazard ratios of 1.02 (95% CI 1.01–1.04), 1.68 (95% CI 1.00–2.81) and 2.27 (95% CI 1.26–4.07), respectively]. Assuming a threshold of £20 000 per QALY gained, no monitoring was most cost-effective, but all extended periods were cost-effective vs. 3- or 6-monthly monitoring.

Conclusions
Anti-TNFα drugs were uncommonly discontinued owing to abnormal monitoring blood tests after the first year of treatment. Extending the duration between monitoring blood tests was cost-effective. Our results produce evidence for specialist society guidance to reduce patient monitoring burden and healthcare costs.

Citation

Abhishek, A., Stevenson, M. D., Nakafero, G., Grainge, M. J., Evans, I., Alabas, O., …Williams, H. C. (2024). Discontinuation of anti-tumour necrosis factor alpha treatment owing to blood test abnormalities, and cost-effectiveness of alternate blood monitoring strategies. British Journal of Dermatology, 190(4), 559–564. https://doi.org/10.1093/bjd/ljad430

• Journal Article Type: Article
• Acceptance Date: Oct 31, 2023
• Online Publication Date: Nov 1, 2023
• Publication Date: 2024-04
• Deposit Date: Nov 20, 2023
• Journal: British Journal of Dermatology
• Print ISSN: 0007-0963
• Electronic ISSN: 1365-2133
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 190
• Issue: 4
• Pages: 559–564
• DOI: https://doi.org/10.1093/bjd/ljad430
• Keywords: Dermatology
• Public URL: https://keele-repository.worktribe.com/output/636986
• PMID: 37931161