Evaluation of strategies for increasing response rates to postal questionnaires in quality control of nasal septal surgery

BACKGROUND: Postal questionnaires are often used to assess the results of nasal septoplasty, but response rates vary widely. This study assesses strategies designed to increase the response rate. METHODS: Postoperative questionnaires using visual analogue scales (VAS) for nasal obstruction were mailed to 160 consecutive patients alternately allocated to one of two groups. Group A received the questionnaire in the usual manner and group B received a modified cover letter with hand-written name and signature and a hand-stamped return envelope. RESULTS: Of the 80 patients in each group, 47 (58.8%) in group A and 54 (67.5%) in group B returned the questionnaire (p = 0.25). There were no age or gender differences between the groups, nor did the pre- and postoperative VAS scores differ between the groups. CONCLUSION: The strategies used in this study increased the response rate to postal questionnaires by 8.7% points, but this was not a statistically significant or clinically meaningful improvement.