Evaluation of a Web-Based, ‘Purchase Event’ Intensive Monitoring Method for Pharmacovigilance of Natural Health Products: Lessons and Insights from Development Work in New Zealand

Introduction Intensive monitoring methods are used in pharmacovigilance for prescription medicines but have not yet been implemented for natural health products (NHPs). Objectives Our objective was to assess feasibility issues with a new ‘purchase event’ intensive monitoring method for pharmacovigilance of NHPs, including pharmacy and NHP purchaser recruitment rates, collection of NHP purchaser key patient identifier information for data linkage and quality and completeness of data. Methods For the Ginkgo study, 213 community pharmacies in the Auckland (Aotearoa New Zealand) District Health Board area were invited to participate. Staff in participating pharmacies ( n = 3 [1.4%]) recorded ginkgo product sales and gave purchasers a study invitation card (October 2015–January 2016). Ginkgo purchaser participants were emailed links to web-based baseline and follow-up questionnaires about adverse events occurring during/after taking ginkgo. Participating pharmacists and consumers were invited to provide qualitative feedback about the study. For the NHP-Lite study, all NHPs were included for monitoring. Community pharmacies in the Green Cross Health network were invited to participate. Participating pharmacy staff gave all NHP purchasers a study invitation card over a 2-week period (May 2016). NHP purchaser participants were emailed links to web-based baseline, follow-up and feedback questionnaires. Results Few community pharmacists (Ginkgo study, n = 3; NHP-Lite study, n = 18) and NHP purchasers (Ginkgo study, n = 0; NHP-Lite study, n = 4) participated. Pharmacists (Ginkgo study, 3/3; NHP-Lite study, 11/18) described several reasons for participating and suggested ways to increase consumer recruitment, including simplifying study procedures. Conclusions These web-based, purchase event, intensive monitoring studies, with cohorts built through NHP purchases in pharmacies, identified substantial issues with recruiting pharmacists/pharmacies and NHP purchasers that, at present, render such studies unfeasible. Future studies need to consider other methods of recruiting NHP purchasers and develop a simple method for recording NHP purchases.