Abstract: ObjectiveTo investigate reasons of refusal to follow-up for hepatitis B vaccination outcome among parents of small children and to provide evidences for effective implementation of vaccination programs.MethodsTotally 709 healthy children aged 0-6 years were surveyed with a questionnaire completed by their parents and followed up after taking physical examination including detections of 5 indicators of hepatitis B virus infection between June 2013 to December 2014 at a general hospital in Urumqi city and the parents of the children not undertaking the follow-up for outcome of the vaccination were surveyed with a phone or face-to-face interview.Fault tree analysis was adopted to examine main reasons of the refusals.ResultsOf the children's parents surveyed,8.7%refused to have a blood detection to their children and the children with mothers having the education of college and above showed a significantly higher proportion for refusal to blood detection compared to those with mothers having lower education(10.1%vs.4.6%,P<0.05).Only 6.8%of the children were followed up and the rate of loss to follow-up was 93.2% six months after the establishment of the cohort.The main reason for the parents of refusal to the follow-up was subjective factors(72.9%),including without confidence in the researchers (45.7%),without recognition for the capability of the researchers(18.0%),and without knowledge on the study (17.3%).ConclusionThe increase of the compliance of participants for medical research programs could be achieved by understanding the needs of the subjects,upgrading the capability of the researchers,and improving doctor-patient relationship.