Conclusion: 1. In relation to GP treated with DAA, HACU population is younger, with male predominance and different genotype distribution (1a most frequent, 3 more represented). 2. More than 40% of the patients in the HACU group have advanced stage of fibrosis or cirrhosis. 3. SVR12 is excellent in both groups with proper strategies that avoid tracking losses. SAT276 Modelling the cost of hepatitis C virus transmission in Pakistan Aaron G. Lim 1 , Josephine Walker 1 , Nyashadzaishe Mafirakureva 2 , Gul Ghuttai Khalid 3 , Huma Qureshi 4 , Hassan Mahmood 5,6 , Adam Trickey 1 , Hannah Fraser 1 , Khawar Aslam 3 , Gregoire Falq 7 , Camille Fortas 8 , Hassaan Zahid 3 , Ammara Naveed 9 , Rosa Auat 3 , Quaid Saeed 10 , Charlotte Davies 1 , Christinah Mukandavire 11 , Nancy Glass 12 , David Maman 7 , Natasha Martin 13 , Matthew Hickman 1 , Margaret May 1 , Saeed Sadiq Hamid 14 , Anne Loarec 7 , Francisco Averhoff 12 , Peter Vickerman 1 . 1 University of Bristol, Population Health Sciences, Bristol Medical School, Bristol, United Kingdom; 2 University of Sheffield, Health Economics and Decision Science, Sheffield, United Kingdom; 3 Médecins San Frontiè res, Brussels, Belgium; 4 Doctors Plaza, Karachi, Pakistan; 5 Pakistan Health Research Council, Islamabad, Pakistan; 6 World Health Organization, Islamabad, Pakistan; 7 Epicentre, Médecins San Frontiè res, Paris, France; 8 Pasteur Institute, Paris, France; 9 Pakistan Kidney and Liver Institute and Research Center, Department of Gastroenterology and Hepatology, Lahore, Pakistan; 10 National AIDS Control Programme, Islamabad, Pakistan; 11 Imperial College London, Department of Infectious Disease Epidemiology, London, United Kingdom; 12 US Centers for Disease Control and Prevention, Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, United States; 13 University of California San Diego, Division of Infectious Diseases and Global Public Health, Department of Medicine, San Diego, United States; 14 Aga Khan University, Karachi, Pakistan Email: aaron.lim@bristol.ac.uk Background and Aims: Pakistan has the world’s second-largest hepatitis C virus (HCV burden). The World Health Organization (WHO) HCV-elimination strategy advocates for a reduction in HCV incidence by 80% by 2030, but little is known about how this could be achieved and the costs of doing so in Pakistan. Method: A general population HCV transmission, screening, and treatment model was developed and calibrated using available data from Pakistan, incorporating cost data on diagnostics and HCV treatment. We modelled the impact and costs of alternative strategies for scaling-up screening and HCV treatment to determine what is needed and the resulting costs of achieving the WHO HCV incidence target in Pakistan. Results: One-time screening of 90% of the 2018 population by 2030, with 80% referral to treatment, leads to 14 million individuals being screened and 350,000 treated annually, decreasing incidence by 27% over 2018–2030. Prioritising screening to higher prevalence groups ( people who inject drugs (PWID) and adults >30 years) and introducing re-screening (annually for PWID, otherwise 10-yearly) increases the number screened and treated by half and decreases incidence by 51%. Decreasing HCV incidence by 80% requires doubling the primary screening rate, increasing referral to 90%, re- screening the general population every 5-years, and re-engaging those lost-to-follow-up every 5-years. This could cost USD$8 billion, reducing to USD$4 billion with lowest costs for diagnostic tests and drugs, including healthcare savings, and implementing a simplified treatment algorithm. Conclusion: Pakistan will need to invest up to 9% of their yearly health expenditure to enable sufficient scale-up in screening and treatment to achieve the WHO HCV-elimination target for incidence. SAT277 The best strategy for retrieval of hepatitis C patients lost to follow up: randomized clinical trial Alberto Hernández Bustabad 1 , Dalia Morales Arraez 1 , María Cristina Reygosa Castro 1 , Orestes Crespo 2 , Felicitas Diaz-Flores 3 , Enrique Quintero 1 , Manuel Hernandez-Guerra 1 . 1 Hospital Universitario de Canarias, Hepatology and Gastroenterology Department, La Laguna, Spain; 2 Hospital Universitario de Canarias, Administrative Unit, La Laguna, Spain; 3 Hospital Universitario de Canarias, Central Laboratory, La Laguna, Spain Email: mhernandezguerra@gmail.com Background and Aims: In order to achieve hepatitis C virus (HCV) WHO 2030 elimination goals, stakeholders should increase the rate of new diagnoses and linkage to care those lost to follow-up. Different strategies have been implemented to overcome barriers related to diagnosis, but there is a lack of studies approaching the best retrieval strategy for those lost to follow-up . Our aim was to evaluate the efficacy and effectiveness of two different strategies for retrieval of previously diagnosed HCV patients lost to follow-up, which is key to reach microelimination in our healthcare area. Method: from data files of laboratory and microbiology charts since 2005 we identified patients with positive HCV antibodies without RNA request or positive RNA without a subsequent negative RNA lost to follow-up . Those still alive with currently available data for contact (by phone and mail) and in our healthcare area were randomly assigned (NCT04153708) (n=176 each arm) in any of the two strategies: 1) phone calls to provide patients an appointment and 2) invitation mail letter with a scheduled appointment. We evaluated efficacy as the rate of patients who turn up for the appointment in each strategy and effectiveness taking into account the use of resources. Statistical analysis was performed with Chi2, t-student and Poisson regression. The study was approved by the local Hospital Ethics Committee. Results: 352 subjects were included in both strategies (74.6% men, mean age 51.3±13.3 years-old) with no differences between groups. In strategy 1, 8.7% of the patients were excluded due to change of the holder of the phone line, whereas, in strategy 2, 11% of the letters failed to reach the address and were returned. Eventually, in strategy 1, 42.4% did not answer the phone call and 10.2% were not interested to participate. The rate of patients that turned up for the scheduled appointment was higher in the strategy 1 (median 9 days, [1–17]) POSTER PRESENTATIONS S791 Journal of Hepatology 2020 vol. 73 | S653–S915