Nurturing Longitudinal Samples 2.0

While longitudinal designs can provide significant advantages compared to single measurement/cross sectional designs, they require careful attention to study infrastructure and the risk of attrition among the sample over multiple time points.

The strategies used to design and manage an appropriate infrastructure for a longitudinal study and approaches to retain samples are explored using examples from 2 studies, a 25-year study of persons living with multiple sclerosis and a 10-year longitudinal follow-up of breast cancer survivors.

Key strategies (developing appropriate infrastructure, minimizing costs to participants, and maximizing rewards of study participation) have helped address the serious threat of attrition in these longitudinal samples.

Implementation of these strategies can help mitigate some of the disadvantages and leverage the strengths of longitudinal research to produce reliable, insightful, and impactful outcomes.