Background/Purpose: Few studies have explored cost consequences of non-persistence in the treatment with Subcutaneous Tumor Necrosis Factor-Alpha Inhibitors (SC-TNFi) in Inflammatory Arthritis (IA; rheumatoid arthritis [RA], psoriatic arthritis [PsA] and ankylosing spondylitis [AS]). Hence, the aim of this study was to estimate the costs associated with non-persistence among biologics-naïve patients treated with SC-TNFi for IA.

Methods: An adult and biologic treatment-naïve population initiating treatment for IA with any available SC-TNFi (adalimumab, etanercept, certolizumab, and golimumab) between May 1, 2010 and December 31, 2017, was identified in the Swedish Health Data Registers. Treatment persistence was derived based on information from filled prescriptions and a grace period of 60 days. Patients not reaching the specified treatment maintenance period (i.e. persistent < 6 months) or with insufficient follow-up data were excluded. Patients were deemed non-persistent if treatment was discontinued or if they switched to another novel synthetic or biologic disease-modifying anti-rheumatic drugs (DMARDs). Costs of non-treatment related Health Care Resource Utilization (HCRU) were captured and compared 12-months before and after the date of non-persistence (i.e. index date). Resources comprised specialized outpatient care, inpatient stays, and medication other than DMARDs. The analysis was conducted on a propensity score matched cohort based on the predicted probability of non-persistence, within two years from treatment initiation; controlling for baseline characteristics collected 12 months before treatment initiation (e.g. age, gender, diagnosis, and level of education). Non-persistent patients (cases) were matched 1:1, without replacement, to persistent patients with at least 12 months additional time on treatment (controls). The number of days on treatment in cases was also used to identify the index date in controls, enabling comparisons across the same time period in relation to treatment initiation.

Results: A total of 9,976 eligible patients initiating SC-TNFi treatment for IA were identified. A PSM cohort was derived with 2,969 cases and an equal number of controls. In this cohort overall, 63% were female, the mean age was 50 years, and 52%, 22%, and 26% were diagnosed with RA, PsA and AS, respectively. While non-persistent patients increased their total non-treatment related cost of HCRU from the 12-month period before to the 12-month period after the index date, persistent patients decreased their costs between the same time periods (Table 1). Figure 1 shows the monthly development of total non-treatment related HCRU costs from 12 months before to 12 months after the index date. Costs were more similar before the index date and the differences increased for non-persistent patients in conjunction with their treatment discontinuation.

Conclusion: Among patients initiating SC-TNFi treatment for IA, non-persistent patients incurred significantly higher non-treatment HCRU costs compared to those who were persistent during the year following index date. This highlights the impact of therapy persistence from an economic point of view, adding further aspects to the clinical perspective.

Table 1. Costs of non-treatment related health care resource utilization 12-months before and after index date in, propensity score matched, persistent and non-persistent patient’s treated with SC-TNFi for IA

Figure 1. Development of costs for non-treatment related health care resource utilization 12-months before and after index date in, propensity score matched, persistent and non-persistent patient’s treated with SC-TNFi for IA

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/cost-of-non-persistence-in-the-treatment-with-subcutaneous-tumor-necrosis-factor-alpha-inhibitors-of-inflammatory-arthritis-a-propensity-score-matching-approach/