This paper represents the results of the original study based on interviews of chronic hepatitis С patients to explore their preferences for the DAA antiviral treatments attributes. The study has some advantages. Among them are: originality (a limited number of studies with the same focus of the research was identified for DAA in HCV-infected patients’ treatment); actuality (DAAs are a novel and effective against HCV infection drug group) and internationality (the respondents were from different countries). The objective was stated by the authors. Though there are matters for additional considerations. First, who is addressed by this paper? I suppose that every healthcare provider would prefer more effective, less harmful and shorter treatment for any of the disease, covered by the patient’s policy (see, for example M Shumway et al, 2019). In case of this paper is addressed to pharmaceutical companies or drug inventors, then another aspect should be considered: whether a lot of new antivirals for HCV are at the end-of-pipe? It seems that those in the market are supposed to be good enough to balance expectations on treatment efficacy, duration, and safety and, partially, costs. Despite mentioned positive moments, the study has several flaws that may cross out all the advantages. 1. First: is this is a clinical trial? If so, a review/aproval of the study protocol and materials given to the respondents (like educational tool) by IEC/IRB should have been obtained. Please, provide more details on why the study obtained an exemption from a full review from IEC. 2. As a consequence, if this is a clinical trial, then according to the international guidelines, including the GCP and GPP3, it should have been registered on public Web sites like ClinicalTrials.gov or similar before participants are enrolled to make the process of the data collection clear. 3. The data sources are not well-described. Who were participants of the survey? If the study describes the preferences of the HCV-infected persons, then it should be clear that a) the interviewed people are really infected, b) they represent a general population of HCV-infected people, and c) their answers are not biased. Otherwise, no mention of HCV-infected patients should is applicable in the paper and my suggestion is to use "members of the community" or "respondents" instead of "patients"

1. A number of methods is described as a support for CHC diagnosis: “blood test, liver biopsy, liver ultrasound scan, computed tomography scan, magnetic resonance imaging, or Home Access Hepatitis C Check kit”. But neither a CT, nor a MRI and ultrasound examination can support the diagnosis of viral hepatitis С infection. Some of the blood tests really can. But the information about which of them were used (anti-HCV, HCV RNA?) is lacking.
2. According to the Table 2, the population of the respondents was not homogeneous. Some of them were co-infected by HBV and/or HIV. Could it impact the study results?
3. Does the respondents’ demography represent a general population of HCV-infected persons? No information is provided, though it is necessary to understand that these answers are what the goal group really want.
4. Does the number of the interviewed persons sufficient to reflect the opinion of the general population? Was the power analysis performed to support this?

Statistical methods are poorly described. The paper does not contain a description or a diagram of the flow of the answers (whether all of the questionnaires were complete as full and correct? and whether all of them were included to the study results?). Type of regression analysis is not mentioned. Step-by-step statistica approach is not described. These findings are serious limitation to clearly understand findings, bias, and study limitations.//

1. The spectrum of the side effects of the DAA seems to be not complete. Why did the authors focus on these AEs only?
2. According to the table 2, the participants had a spectrum of comorbidities. Some of these diseases requires treatment different from the PPIs or statins. And at least part of such medications may have greater possibility of side effects when co-administered with DAAs. Why only PPIs and statins were selected for the interview?
3. There were studies designed to assess the duration of treatment, the number of pills taken per time, and the frequency of pills intake. They showed the inverse relationship between these factors and adherence to treatment. Should this be included to the discussion?
4. May the understanding of the “importance” of the disease by the respondent be a reason why the number of pills taken per time and per day was not considered significant?