Participants Who Left a Multiple-Wave Cohort Study Had Similar Baseline Characteristics to Participants Who Returned

Abstract

PURPOSE:Research on determinants of an individual's pattern of response, considered as a profile across time, for cohort studies with multiple waves is limited. In this prospective population-based pregnancy cohort, we investigated baseline characteristics of participants after partitioning them according to their history of response to different interview waves. METHODS: Data are from the Mater-University of Queensland Study of Pregnancy 1981 to 1983 cohort, Brisbane, Australia. Complete baseline information was collected for 7223 of 7535 eligible individuals (95.9%). Follow-up occurred at 6 months, 5 years, and 14 years. Response rates were 93.0%, 72.5%, and 71.8%. Participants were allowed to leave and reenter the study. Participants were categorized as always, intermittent, or never responders. Intermittent responders were categorized further as leavers (responded at least once before leaving the study) or returners (left the study before reentering). RESULTS: Participants who always responded were older, more educated, married, Caucasian, and nonsmokers and had higher incomes. Intermittent responders shared similar baseline characteristics. Relative risk for being an intermittent responder was located between risks for always or never responding. CONCLUSIONS: Participants who left and reentered the study had baseline characteristics similar to participants who responded at least once and then left the study.

Parental pre‐pregnancy BMI influences on offspring BMI and waist circumference at 21 years

“…However, the correlation between maternal reported pre‐pregnancy weight and actual weight at the first antenatal visit was very high (0.95) 43 . Multiple imputation and inverse‐probability weighting were used to examine potential attrition bias in the MUSP and we found missing values did not make major differences to our conclusions 20,42 …”

“…The response rate at six‐month follow‐up was 93%; at five year follow‐up 73%; at 14 year follow‐up 72% and 21 year follow‐up 57%. In general, participants lost to follow‐up were more likely to be less educated, depressed and smokers 42 . Attrition bias may have affected the subgroups who had data included in the analysis.…”

Determinants of subject visit participation in a prospective cohort study of HTLV infection

“…A high participant loss rate will impact the ability to draw valid conclusions. This is particularly relevant in longitudinal studies where loss of data points within or between visits can distort the relationships between measurements [3,4]. Many strong predictors of attrition, such as health problems and socioeconomic factors [5], race/ethnicity [6], and substance abuse [7] have been explored in efforts to develop strategies to maintain participation in a long term cohort study.…”

Who does not participate in a follow-up postal study? a survey of infertile couples treated by in vitro fertilization

“…For example, in the NEMESIS study investigating mental health in the general population in the Netherlands, 20% of attrition in the second wave was due to failure to locate or to contact respondents after only one year of follow-up [27]. To mitigate the problem of contact, most prospective cohorts use processes such as annual update of address or contact details of relatives or friends [28,29]. However, even with efforts to trace participants, in the Australian Longitudinal Study on Women’s Health 21% of 18- to 23-year-old women could not be contacted 4 years after the first survey [8].…”