Strengths and limitations
opioid dependence, fatigue, OAT, infectious disease, cognitive impairments
INFECTIOUS DISEASE
A major strength of this study is its trial design of individual randomization with balanced groups, which minimizes potential confounding. Furthermore, we included PWIDs who usually struggle with adherence to standard HCV treatment and have frequently discontinued previous HCV assessment and treatment in centralized infectious disease outpatient clinics. A limitation of this study is in the selection of outpatient clinics, where most participants received OAT to recover from opioid dependence, affecting the generalizability of our results to non-OAT populations. Another limitation is the almost 30% loss-to-follow-up of the FSS-9 assessment at EOT12 and the exclusion of 18 randomized participants due to missing FSS-9 assessments during the period. This may explain the five-point higher FSS-9 sum score in the intervention group than in the control group at baseline. Furthermore, due to system and individual delays and changes in national guidelines for HCV treatment throughout the study period, the FSS-9 assessments were not conducted in exact concurrence with HCV treatment initiation and EOT12. This could affect the interpretation of the predicted fatigue changes from baseline. Furthermore, the FSS-9 did not consider specific issues related to completing the questionnaire, such as cognitive impairments and physical disabilities. These issues could introduce information and recall bias of reported fatigue symptoms. Moreover, a time-to-treatment analysis from the first fatigue measurement to the HCV treatment initiation could be performed to adjust for changes in fatigue. However, the fatigue level was assumed to be substantially unchanged during the few weeks from the first health assessment to the HCV treatment initiation.