Longitudinal Outcomes of GastroIntestinal symptoms in Canada (LOGIC): key factors for an effective patient retention in observational studies.Can J Clin Pharmacol. 2009 Winter; 16(1):e140-50.CJ
Longitudinal Outcomes of GastroIntestinal symptoms in Canada (LOGIC) is an ongoing study on irritable bowel syndrome (IBS) treatment patterns and health outcomes in routine Canadian clinical practice. Advancements in understanding IBS, a chronic multifaceted GI disorder, may be possible through methodical observational studies. The objective of this paper is to describe site recruitment techniques and extensive subject follow-up methodology used to facilitate a high return rate of questionnaires from this population-based study of subjects with IBS.
Invitation letters along with protocol synopses and preliminary site assessment questionnaires were faxed to potential sites across Canada. There were 1,556 subjects enrolled in this study from general practitioner sites (GP) and specialist sites (SP) in Canada. Subjects were compensated for the return of questionnaires reporting symptoms, quality of life, productivity, healthcare and resource utilization at baseline, Month 1, 3, 6, 9, and 12. Upon the return of questionnaires, subjects received thank you cards which included a reminder of the next questionnaire's due date. If subject questionnaires were not received within 2 weeks after the due date, the subjects received a reminder letter in the mail.
The methodology in the LOGIC study allowed for a high patient questionnaire return rate (89%) through extensive subject reminders and follow-up. Subject participation throughout the study was not found to be linked to study site size or type (GP or SP).
Questionnaire based observational studies may benefit from focusing resources on increasing questionnaire return rates to effectively maintain data reliability and also reduce non-response bias.