Effect of incentives on recruitment and response rate in a community-based pharmacy practice study

Abstract

Objectives - To study the feasibility of carrying out a community pharmacy-based drug utilisation study of H2 antagonists and alginate-containing preparations, and to study the effect of two methodological variations - payment of pharmacists and the free issue of medicines - on recruitment rates and response rates. Method - Pharmacists were asked to recruit customers into the study after deciding that one of these products was appropriate for purchase. Customers were asked to provide their signed consent, their name, address and information about their general practitioner and to complete an initial questionnaire provided by the pharmacist and a second questionnaire which was sent out by the researchers two weeks later. In 20 of the pharmacies the medicines were offered free once customers had agreed to participate; in the remaining pharmacies, customers paid the normal retail price for the product. All pharmacies received incentive payments for each of the three months in the second half of the study period in which they recruited five or more customers. Setting - Thirty-nine community pharmacies in Scotland and Wales. Key findings - Similar numbers of customers were recruited to the study irrespective of whether free medicines were offered. Significantly more (P < 0.001) customers recruited by pharmacies providing free medicines returned both the first (339/383) and second questionnaires (264) than those recruited by pharmacies not providing free medicines (269 and 208/384, respectively). Of the 608 customers who returned the first questionnaire and were subsequently issued with a second questionnaire, 77.6 per cent returned it; there was no difference in return rates between customers who received free medicines and those who did not. Incentive payments to pharmacies resulted in a small increase (14 per cent) in recruitment rate in the second half of the study and no difference in response rates from the customers recruited. Conclusion - The study established the feasibility of undertaking drug utilisation studies with high response rates in community pharmacies. The provision of free medicines increased customer response rates, but incentive payments for pharmacists showed no clear effect on recruitment rates.