Never plan a population based cohort study on a rainy Friday after a sunny Thursday

摘要

Many cohort studies have identified factors leading to higher attrition or drop-out rates of study subjects. Low educational level, low household income or participant's gender are such known factors [1, 2]. But no study to our knowledge has addressed the influence of weather conditions or general cultural factors on the rate of missed or canceled study appointments. After 1 year of experience with the LIFE (Leipzig Research Centre for Civilization Diseases) Child study cohort and about 1,000 study appointments we analyzed our data and identified such general factors. The LIFE Child study is a large prospective population based cohort study of children and adolescents in Leipzig (Germany). We plan to recruit 10,000 children from fetal life to age 18 years with annual follow-up examinations over 10 years. Our aim is to understand what mechanisms and mediators be it (epi)genetic, metabolic or environmental influence health and development of children and adolescents in modern societies. Details of the study protocol have been published elsewhere [8].