Evaluation of an intervention to improve successful completion of the Mini-AQLQ: comparison of postal and supervised completion

Abstract
Previous postal administration of Mini Asthma-related Quality of Life Questionnaire (Mini-AQLQ) (validated for self-completion under supervision) resulted in 12.7% completion error rate. To administer the Mini-AQLQ by post with instructions, and to compare completion errors with our previous study and usable response rate with supervised self-completion. The Mini-AQLQ, with an instruction sheet, was posted to 96 participants from UK general practice, for completion 1 week before supervised self-completion in the surgery. 94/96 (98%) postal questionnaires were returned: the error rate of 10.6% was similar to our previous study (postal versus previous: 10/94 versus 23/181: P = 0.62). 86/96 (90%) attended for supervised completion with no completion errors (supervised versus postal: 0/86 versus 10/94: P ≤ 0.01) Overall usable response rates were similar. (supervised versus postal: 86/96 versus 84/96, P = 0.65). Our instruction sheet did not significantly reduce postal completion errors, however the good postal return rate achieved comparable overall usable response rates to supervised administration.