Effects of non-medical switching on outcomes among patients prescribed tumor necrosis factor inhibitors

Objective: To evaluate health care use and outcomes among patients who experienced a non-medical switch of their prescribed anti-tumor-necrosis-factor biological agent (anti-TNF) for cost containment reasons.

Methods: Retrospective evaluation of Humedica electronic health records of patients ≥18 years old with anti-TNF treatment for immune conditions. Using natural language processing, stable patients who experienced a non-medical switch (for cost reasons) of their anti-TNF between 2007 and 2013 were identified (NMS cohort, n = 158) and matched to patients who did not (control cohort, n = 4804). Rates of office visits, emergency department visits, and hospitalizations at 30, 90, and 365 days following were evaluated. Medication-related adverse events, defined as subsequent medication change due to a side effect and/or efficacy-related reason were also compared.

Results: Adjusted rates of office visits were higher among the NMS cohort than the control cohort at 30 (46.4% vs. 31.7%, p < .001), 90 (71.0% vs. 57.0%, p < .001), and 365 days (87.8% vs. 76.8%, p < .001). Rates of emergency department use and hospitalization were comparable between cohorts. The NMS cohort had higher adjusted rates of medication-related adverse consequences (both increased side effects and diminished efficacy) than the control cohort at 30 (13.8% vs. 4.0%, p = .003), 90 (31.6% vs 9.6%, p < .001), and 365 days (54.7% vs. 20.3%, p < .001). Compared with controls, the NMS cohort had higher adjusted rates of subsequent medication change within 1 year (27.82% vs. 13.9%, p = .001).

Conclusion: Non-medical switching among patients prescribed anti-TNFs was associated with increased health care use, medication-related side effects, and reports of diminished efficacy.