Recruitment and retention of a challenging population: Lessons learned and design implications

The purpose of this article is share the lessons learned from recruiting and retaining adults with type 2 diabetes and solid tumor cancer into a longitudinal study exploring the relationship among chemotherapy, glycemic control, and symptoms.

Twelve-week longitudinal study, recruited thirty-four adults 21years or older with pre-existing type 2 diabetes and a solid tumor cancer, from three community based cancer centers who were eligible to receive outpatient chemotherapy.

Fisher's Exact Test (categorical variables) and Logistic Regression (continuous variables) were used to evaluate factors associated with participant withdrawal. A dichotomous attrition variable was created to identify those who dropped out of the study before the final week and those who completed.

Thirteen of the 34 participants completed the study. Symptom severity, baseline HbA1c and metastases were all identified as being factors that potentially influenced attrition. Recruitment was improved once recruiters were hired at each of the cancer centers and adjustments made to the inclusion criteria.

Several design elements need to be considered to address attrition in future including the use of recruiters, inclusion and exclusion criteria, consent timing, data collection schedules, participant characteristics, participant burden, and support person identification.