Overview
The goal of this observational, multicenter , real-world study is to evaluate the long-term outcomes of different antiviral therapies in adults with chronic hepatitis B (CHB). The main questions it aims to answer are: What is the 5-year incidence of hepatocellular carcinoma (HCC) under various treatment regimens? How do rates of HBsAg seroclearance, decompensated cirrhosis, liver fibrosis progression, and other virological and clinical outcomes compare across regimens? Researchers will compare real-world treatment arms-including nucleos(t)ide analogue (NA) monotherapy (e.g., entecavir, tenofovir), PegIFN based regimen (e.g., PegIFN monotherapy, PegIFN plus NA combinations)-to identify optimal strategies for reducing HCC risk and improving functional cure rates.
Participants will undergo routine clinical care with no study-imposed interventions; data on demographics, medical history, symptoms, laboratory tests (e.g., HBsAg, HBV DNA, liver function), imaging (e.g., ultrasound, elastography), and clinical events will be collected prospectively (for up to 5 years in some cohorts) or retrospectively from medical records at baseline and scheduled follow-up visits (e.g., every 3-12 months initially, then annually).
Description
The OASIS study is a multicenter, observational, real-world cohort study designed to evaluate long-term outcomes of antiviral therapies for chronic hepatitis B (CHB). It compares nucleos(t)ide analogue (NA) monotherapy, pegylated interferon based regimen without randomization or blinding. Treatment decisions follow routine clinical guidelines, physician expertise, and patient-specific factors. The study includes three cohorts: Prospective (PS, 5-year follow-up post-consent), Retrospective-Prospective (RPS, retrospective from baseline ≥September 2020 to consent, then 5-year prospective), and Retrospective (RS, data from September 2020 to protocol implementation). The target of 33,000 patients was determined based on patient flow across sub-centers, ensuring sufficient power to detect differences in 5-year HCC incidence (primary endpoint) and secondary outcomes (e.g., HBsAg seroclearance rates).
Eligibility
Inclusion Criteria:
- Male and female patients with age ≥18; subjects who are over 70 years of age must be in generally stable health conditions.
- There should be evidences that HBsAg has been positive for more than 6 months or HBV-related histological changes.
- Planned or currently receiving potent low-resistance NAs \[entecavir (ETV), tenofovir disoproxil fumarate (TDF), tenofovir alafenamide fumarate (TAF), or tenofovir amibufenamide (TMF)\], or planned to receive PegIFNα-2b, either treated or treatment-naïve.
- Agree to participate in the study and sign the patient informed consent form.
Exclusion Criteria:
- Hepatocellular carcinoma (diagnosed or planned for treatment) or liver failure at baseline
- Concurrently participating in other interventional clinical trials.
- Any other conditions deemed unsuitable by investigators or preventing compliance with study requirements.
