Response rate of patient reported outcomes: the delivery method matters

BACKGROUND: Patient Reported Outcomes (PROs) are subjective outcomes of disease and/or treatment in clinical research. For effective evaluations of PROs, high response rates are crucial. This study assessed the impact of the delivery method on the patients’ response rate. METHODS: A cohort of patients with a unilateral vestibular schwannoma (a condition with substantial impact on quality of life, requiring prolonged follow-up) was assigned to three delivery methods: email, regular mail, and hybrid. Patients were matched for age and time since the last visit to the outpatient clinic. The primary outcome was the response rate, determinants other than delivery mode were age, education and time since the last consultation. In addition, the effect of a second reminder by telephone was evaluated. RESULTS: In total 602 patients participated in this study. The response rates for delivery by email, hybrid, and mail were 45, 58 and 60%, respectively. The response rates increased after a reminder by telephone to 62, 67 and 64%, respectively. A lower response rate was associated with lower level of education and longer time interval since last outpatient clinic visit. CONCLUSION: The response rate for PRO varies by delivery method. PRO surveys by regular mail yield the highest response rate, followed by hybrid and email delivery methods. Hybrid delivery combines good response rates with the ease of digitally returned questionnaires.