Clinical and Economie Effects of a Therapeutic Substitution Policy for Proton Pump Inhibitors in Aboriginal Patients in Northern Communities in Canada’s Northwest Territories

Background and objectiveProton pump inhibitors (PPIs), which are used to treat gastroesophageal symptoms, can vary in price, but are thought not to differ in clinical benefits. Health Canada’s Non-Insured Health Benefits Program instituted a therapeutic substitution policy for PPIs as a cost-containment strategy in 2005. The objective of this pilot study was to identify signals of what might be occurring as a result of this policy in Aboriginal people in northern, isolated communities.MethodsFive pharmacies in the Northwest Territories identified a sample of patients who were affected by the substitution policy. Eligible patients who provided informed consent had a face-to-face or telephone interview with a pharmacist using a standardized questionnaire.ResultsOf 66 identified patients, 44 consented to be interviewed, and 40 were used in the analyses: 70% were female and the mean age of the patients for whom data were analyzed was 57 years. Thirty-four (85%) patients reported health problems after the switch in PPI. Nineteen (48%) patients visited a local nursing station or physician and six (15%) visited a hospital for assessment because of perceived health problems following the switch in PPI. During the initial 15 months of the therapeutic substitution policy, there was a net increment in drug costs of $Can30.96 (year 2006 values) per person due to drug wastage, delayed switching to the policy PPI, and switching back to the patient’s original PPI. A conservative estimate of the additional healthcare service costs related to health problems perceived to be due to the switch was $Can36 624.41 for the 40 patients.ConclusionsThe majority of the sampled patients who took part in the PPI therapeutic substitution policy experienced problems following the PPI switch that were possibly associated with either diminished treatment efficacy or adverse drug effects. Although causality was not proven, patient perceptions in this sample did influence resource use, resulting in no net savings (average incremental cost of $Can915.61 per patient) during the first 15 months of the policy.