Benefits and barriers to participating in longitudinal research of youth-onset type 2 diabetes: Results from the TODAY retention survey.

BACKGROUND/AIMS: Conducting longitudinal research related to chronic illness in adolescents is inherently challenging due to developmental changes and psychosocial stressors. Participants in the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial were socio-economically disadvantaged as well. This study assessed attitudes and beliefs about retention in TODAY to shed light on the factors that potentially promote and detract from the likelihood of sustained participation. METHODS: After an average 7.3 years of follow-up (range 4.9-9.5), TODAY participants completed a survey examining their perceptions of the benefits and barriers to sustained involvement in the protocol. RESULTS: The most common reasons for staying in TODAY included having a strong relationship with the medical team, getting study-provided diabetes care, access to free diabetes medicine and supplies, and being part of a large study to learn more about how to care for youth-onset type 2 diabetes. The most commonly endorsed challenges included scheduling conflicts, possibly disappointing others, difficulties getting to study visits, and the occurrence of other medical issues. CONCLUSIONS: Similar to other published reports, a supportive relationship with study staff was commonly endorsed as a benefit of engagement in the longitudinal study, suggesting that rapport, staff consistency, and relationship quality are important components of optimal retention. Moreover, our findings suggest the value of trying to remove logistical barriers, such as transportation and scheduling challenges, in order to promote long-term participation in research. Further research is recommended to evaluate factors that contribute to attrition versus retention in an a priori manner within longitudinal studies, especially protocols involving cohorts that are more vulnerable to attrition due to developmental transitions and/or socio-economic challenges. Additional efforts to optimize quantitative and qualitative measurement of barriers would also help to expand our understanding of how to optimally retain participants in longitudinal protocols

Racial Differences in the Relationship of Glucose Concentrations and Hemoglobin A1c Levels

Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0% to 12.0%. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1% in black persons and 8.3% in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95% CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P \u3e 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5% to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes. Primary Funding Source: Helmsley Charitable Trust