A follow-up questionnaire on maternal health was distributed within the Danish National
Birth Cohort (established in 1996–2002) 14 years after the index birth. Responses were …

Background: Participation rates in large cohort studies have decreased during the last 2
decades. The consequences of this trend for relative risk estimation are unknown. Methods …

Background The aim of pregnancy cohorts was to understand causes and development of
health and disease throughout the life course. A major challenge in cohort studies is to avoid …

Loss to follow-up in cohort studies may result in biased association estimates. Of 61,895
women entering the Danish National Birth Cohort and completing the first data-collection …

Self‐selection in epidemiological studies may introduce selection bias and influence the
validity of study results. To evaluate potential bias due to self‐selection in a large …

Longitudinal cohort studies can provide important evidence about preventable causes of
disease, but the success relies heavily on the commitment of their participants, both at …

Self-selection into prospective cohort studies and loss to follow-up can cause biased
exposure-outcome association estimates. Previous investigations illustrated that such …

Background Prospective birth cohorts are essential for identifying associations between
exposures and outcomes. However, voluntary participation introduces a potential bias due …

Background In observational research, choosing an optimal analysis strategy when
variables are incomplete requires an understanding of the factors associated with ongoing …

Background Cohort studies may increase or decrease their selection bias as they progress
through time. The Western Australian Pregnancy Cohort (Raine) Study has followed 2868 …