Attrition and retention in upper limb prosthetics research: experience of the VA home study of the DEKA arm

Purpose: (1) Describe study attrition; (2) identify reasons for attrition, and (3) discuss implications for prosthetic prescription and design of future device studies. Design and methodological procedures used: Completion phase (during in-laboratory training, after training, or home use) was identified for 42 participants. Qualitative data were analyzed to identify attrition reasons. Reasons were classified as related to the DEKA arm, or not.

Results: Study attrition was 57%, with 43% completing the full study. Attrition during the in-laboratory portion was 21%. Reasons for attrition were related to the DEKA arm entirely or in-part for 42%, 25%, respectively. Most common reasons were scheduling/personal (54%); device weight (29%); and dissatisfaction with device (25%). About 21% withdrew because of concerns about compliance with study protocol.

Conclusions: This study had a high attrition rate with evidence of selective attrition due to device characteristics. Strategies to minimize attrition and the importance of tracking reasons for withdrawal are discussed. Given that retention could be an indicator of willingness to adopt the DEKA arm, findings suggest that it would be prudent to provide patients with the opportunity to train with the DEKA arm before a decision is made regarding the appropriateness of the device for the patient. Implications for Rehabilitation This study of a new upper limb prosthesis, the DEKA arm, had a 57% attrition rate with evidence of selective attrition due to characteristics of the DEKA arm. Findings point to the need for strategies to minimize attrition in future studies. Findings also illustrate the importance of tracking reasons for subject withdrawal in longitudinal prosthesis device studies. Because participant retention in longitudinal device studies may be an indicator of future willingness to adopt a device, our findings suggest that it would be prudent to provide patients with the opportunity to train with the DEKA arm before a final decision is made regarding the appropriateness of the device for the patient.