A study on the factors affecting the follow-up participation in birth cohorts

• Published in: Environmental health and toxicology 2016-11, Vol.31, p.e2016023-e2016023
• Main Authors: Park, Bohyun, Choi, Eun Jeung, Ha, Eunhee, Choi, Jong Hyuk, Kim, Yangho, Hong, Yun-Chul, Ha, Mina, Park, Hyesook
• Format: Article
• Language: English
• Subjects: Birth cohort; Brief Report; Loss to follow-up; Participation rate
• ISSN: 2233-6567; 2233-6567
• DOI: 10.5620/eht.e2016023

A stable follow-up participation rate is a very important factor for validity in a cohort study. This study analyzed the factors that affect the participation rate at one hospital-based birth cohort in South Korean. The participants were recruited from the Mothers' and Children's Environmental Health study between 2006 and 2010. The analysis targeted 1751 mothers who participated in a birth cohort. We conducted analyses of general characteristics during pregnancy and those of infants at birth that affect the participation rate of the 6-month follow-up survey. The participation rate for the 6-month follow-up survey was 60.4%. The participation rate in the follow-up of the subsequent period decreased within a 5% to 10% range compared to the number of subjects. The participation rate of premature infants was 16.9% lower than that of a full-term infant (52.6% vs. 69.5%). Analysis showed a 16.7% difference between the participation rate of low-birthweight infants in follow-ups (53.7%) and the participation rate of infants with normal weight (70.4%). The participation rate of mothers who were employed during pregnancy was significantly lower for the 6-month follow-up compared to the participation rate of mothers who were unemployed during pregnancy. In this study, factors such as premature birth, low-birthweight, and the employment status of the mother during pregnancy affected the participation rate of the follow-up survey for the birth cohort at six months. A specific strategy is needed to encourage survey participation for the high risk groups in the follow-ups.