Increasing response rates among open-heart surgery patients on health-related quality of life surveys through an intense longitudinal follow-up algorithm: A cost-benefit analysis

Introduction: The extent of non-respondent bias in samples can be inferred from the response rate. To improve upon our previous follow-up response rate of 44%, we developed a multiple contact algorithm. The impact of the algorithm on response rate and cost of implementation were investigated. Methods: Using a prospective,longitudinal design to collect health-related quality of life and clinical data; we created a follow-up algorithm that provides consistent patient contact and positive reinforcement to improve the response rate. Open-heart cardiac surgical patients are enrolled at time of surgery. The general population is contacted six months post-surgery, then yearly thereafter. The Maze procedure population receives follow-up at additional time points of three, nine, and eighteen months. The type of contacts include: mail survey, reminder postcard, follow-up call(s), thank you postcard if survey complete, and incentive drawing notification. Patients are followed until self-withdrawal, death, or loss to follow-up. Costs were calculated based on number of mailings (paper, postage), personnel, and incentives. Results: Our overall response rate increased by 34.2% to 78.2% (General arm 69.9% [N=339]; Maze arm 90.4% [N=229]). The average number of contacts were 2.1 for General and 2.2 for Maze prior to survey completion; 1.0 and 1.2 post survey completion, respectively. The initial project set-up cost along with study implementations during the first year was approximately $170,000 with an annual projected cost of $103,000. Conclusion: Based on the increase in response rate we conclude that implementation of our follow-up algorithm has been successful and the costs are beneficial and justified.