Chronic hepatitis C virus (HCV) is a major healthcare burden and can lead to cirrhosis, liver failure, hepatocellular carcinoma and death. Although definitive data on long-term outcomes are lacking, studies have shown that sustained virological response to treatment appears to be associated with a decreased rate of disease progression and improved survival. The efficacy of antiviral therapy, however, must be considered in the context of the natural history of HCV. Cirrhosis develops in approximately 30% of patients, while liver-related mortality may occur in 20% of patients overall. Moreover, HCV does not progress at a uniform rate in all patients.
To understand variability in patients' preferences for HCV treatment in order to help inform drug development, formulary decision making, and resource allocation (e.g. number of clinic slots, physicians and nurses to support drug initiation and monitoring).
In this study, we have performed two sets of analyses to understand variability in patients' preferences: 1) we have examined patient preferences for triple therapy vs deferral using conjoint analysis, and 2) we have elicited treatment preferences by asking patients to consider 10 concerns influencing patient willingness to begin treatment. For this second paper, data were analyzed using Best Worst Scaling. Subjects were drawn from patients referred for evaluation of HCV or previously treated for HCV in the VA Connecticut and San Francisco Healthcare Systems.
The conjoint analyses survey demonstrated that subjects could be classified into two distinct groups (probability of membership= 100%) based on their treatment preferences; with the larger group [Group 1, n= 118 (59%)] opting for current treatment and the other [Group 2, n= 81 (41%)] preferring to defer. Treatment preferences among members of Group 1 were equally divided between both antiviral regimens with 47.4% (SE= 0.14) of subjects preferring telaprevir, 48% (SE= 0.15) preferring boceprevir and 4.6% (SE= 0.06) preferring to defer. Subjects self-identifying as African American were more likely to belong to Group 2 (i.e. prefer to defer treatment) than White subjects (51.3% vs. 30.5%). Patients with cirrhosis were less likely to defer treatment compare to those without cirrhosis (40.5% vs 21.3%). Members of Group 1 had a more positive overall beliefs related to treatment for HCV compared to members of Group 2 [mean (SD) score= 28.63 (3.06) vs. 26.46 (2.79), p< 0.0001]. The relationship between race and treatment preference after controlling for the presence of cirrhosis [Adjusted odds ratio (95% CI)= 2.30 (1.26 - 4.20)] was no longer significant after adding beliefs to the model [Adjusted odds ratio (95% CI)= 1.66 (0.87- 3.16)] indicating that that they mediated the relationship between race and treatment preference (Sobel test statistic= -2.68, two tailed p value= 0.007).
With respect to patients' concerns, in the aggregate, subjects worried about three factors: 1) not being cured, 2) having to deal with a lot of side effects, and 3) developing resistance; where not being cured was approximately twice as worrisome as the latter two factors. Segmentation into two groups demonstrated that both groups were concerned about likelihood of cure and coping with side effects, but that only half of the participants were concerned about developing resistance to therapy whereas the others worried about not being able to keep up with their responsibilities. Segmentation into three groups revealed that one third of the subjects had additional concerns related to being able to keep up with their responsibilities and being a burden on others. This latter group was twice as concerned with having to cope with side effects as the other two clusters. A new third smaller group emerged that was most concerned about self-administering injections. Segmentation into four groups revealed a distinct cluster of patients that were focused solely on clearing the virus (not being cured and developing resistance) and was the only group not to report concerns related to coping with side effects. An additional group of patients that were concerned about the risk of depression also emerged in this analysis.
: In summary, deferral is the preferred option for a significant percentage of patients. Patients' perceptions related to the significance of having a chronic viral infection and the burdens of therapy are strongly related to their current treatment decisions. Preference to defer is stronger among African American than Caucasian veterans, and this difference is explained by differences in beliefs. While there are now newer therapies available for HCV, the results of this study provide new insights on the methods used to examine patients' preferences and the major determinants of their treatment choices. Treatment for HCV currently involves selecting among several available all-oral, interferon-free regimens, duration is shorter and cure rates frequently exceed 90%. Treatment does, however, require in-person visits at the medical center every two weeks to pick up medications and for close follow-up. Therefore, patients' perceptions related to the significance of having a chronic viral infection and the burdens of therapy remain relevant to current treatment decisions.
Second, our work emphasizes that in order for patients' preferences to be actionable, they must accurately reflect variability. Segmentation analysis can identify which sets of attributes are preferred by unique groups of patients and which priorities are shared across groups, thus enabling end users to allocate resources that are most likely to benefit the greatest number of patients and/ or tailor programming to focus on patients with specific needs. For example, our results suggest that clinical HCV programs would benefit from investing in resources to help patients cope with side effects; whereas targeted support is appropriate for the smaller numbers of patients who are strongly impacted by concerns related to route of administration and their ability to keep up with their responsibilities. Focusing solely on the aggregate results is misleading and ignores the significant number of patients who are most worried about self-administering injections and a substantial number of patients who are concerned about the risk of depression.
- Clark BT, Garcia-Tsao G, Fraenkel L. Patterns and predictors of treatment initiation and completion in patients with chronic hepatitis C virus infection. Patient preference and adherence. 2012 Apr 4; 6:285-95.