WHERE PATIENTS STAND DEPENDS ON WHERE THEY SIT: CURRENT HEALTH STATUS AND TOLERANCE FOR THERAPEUTIC RISKS
Purpose: Aggressive treatment of inflammatory bowel disease (IBD) often involves immunosuppressant therapies with potential for serious adverse events (SAEs) including infection and lymphoma. Willingness to accept increased SAE risks to prevent future relapses can vary among patients. We test the hypothesis that patients with current active disease are less tolerant of therapeutic risks for treatments to prevent future relapses than patients whose disease currently is in remission.
Methods: IBD patients completed a discrete-choice experiment survey consisting of choices between pairs of constructed IBD therapies. Each treatment profile was defined by three attributes that varied within a predefined range: risk of lymphoma (0%-1%), risk of infection (0%-40%), and time to next IBD relapse (0-10 years). Random-parameters logit was used to estimate patients' willingness to accept tradeoffs among treatment features in selecting medication therapy to avoid future disease relapses.
Results: Patients currently in remission placed greater importance on delaying future relapses than patients with self-reported active symptoms, and asymptomatic patients were willing to accept approximately twice the chance of severe infection and lymphoma to delay a relapse for 5 years compared to patients with active symptoms (Figure 1). Respondents who failed risk comprehension tests showed inconsistent and disordered preferences which significantly altered preference results if included in the model.
Conclusions: Patients, particularly those in remission, are willing to accept significant therapeutic risks to avoid relapses for extended periods of time. Differences between patients in remission and patients with active disease are consistent with utility-theoretic predictions that risk equivalents for a given benefit are larger for individuals at higher reference levels of utility than at lower reference levels. Patients in remission may be averse to losses in health status, while symptomatic patients may have adapted to living with active symptoms and therefore value future relapses less strongly. It also is possible that symptomatic patients stated risk intolerance indicates some degree of scenario rejection because their current treatment is failing to control their IBD symptoms. Preference results are sensitive to risk framing and respondent comprehension; respondent comprehension must be assessed and controlled for during analysis.
Figure 1: Maximum acceptable risks associated with 5 year delay of next relapse