Doctor of Philosophy in Pharmaceutical Sciences (PhD)
Addressing equity considerations in research and care of patients with inflammatory arthritis
Wonderful presentations and feedback today at #VanHEM2018, thank you to @MarkTheHarrison for being a #Greatsupervisor getting me this far!
Dissertations completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest dissertations.
Background: Pregnancy hypertension is a common, potentially fatal condition. New guidance recommends ‘tight’ control of pregnancy hypertension over ‘less-tight’ control. However, guidance also suggests that treatment recommendations consider patient preferences. This dissertation aims to understand how to support patients and providers to make preference-congruent and informed decisions about pregnancy hypertension management.Methods: First, a mixed-methods study, including a best-worst scaling task, of patient preferences for pregnancy hypertension management was conducted. Next, a systematic review built upon ancillary findings by assessing emotion in patient decision aids (PtDAs) for decisions during pregnancy. Using results from the preferences study, the subsequent study re-analyzed the Control of Hypertension in Pregnancy Study (CHIPS) trial using a patient-oriented composite endpoint. A PtDA was developed and assessed for quality and effectiveness. Lastly, a preliminary study explored emotion-regulation in patient decision-making.Results: The mixed-methods preference study (n=210) found that individuals prioritised seven outcomes when choosing how to manage pregnancy hypertension. Latent class analysis identified three preference profiles (a profile comprises participants with similar preferences). Each profile placed different importance on each outcome: 1) ‘equal prioritisers’ valued the outcomes equally; 2) ‘early delivery avoiders’ prioritised avoiding delivery before 34 weeks; and 3) ‘medication minimisers’ prioritised avoiding medication. A systematic review of 39 PtDAs found that most did not address emotion. Reanalysis of the CHIPS trial using a weighted patient-oriented composite endpoint found that while both strategies yielded equal outcomes for equal prioritisers; ‘tight’ control produced better outcomes for early delivery avoiders; and ‘less-tight’ control produced better outcomes for medication minimisers. A prototype PtDA that incorporated these profiles was assessed (n=99) as very acceptable and clear, and significantly improved knowledge. The preliminary emotion study (n=107) found that individuals’ beliefs about their own ability to regulate emotions may limit the benefit of a PtDA. Conclusions: Patient preferences for management of pregnancy hypertension can be broadly described by three profiles. ‘Tight control’ is well-suited to only two of these profiles, emphasizing the importance of shared decision-making in reaching treatment decisions. A PtDA for pregnancy hypertension may help patients make more informed decisions. Future work should explore how to include emotion in PtDAs.
Theses completed in 2010 or later are listed below. Please note that there is a 6-12 month delay to add the latest theses.
BACKGROUND Despite representing less than 2% of prescriptions, biologics accounted for nearly three of every ten dollars spent on prescribed medicines in Canada in 2018. Similar to generics for small molecule drugs, biologic biosimilars are one potential way in which payers can reduce drug spending. In 2019, the government of British Columbia became the first in North America to mandate switching from reference biologics to biosimilars. While a number of other provinces have followed, the impact of these policies remains unclear. Therefore, this thesis examined the current state of biosimilars use in Canada.METHODS This dissertation focused on uptake of and spending on infliximab, etanercept, and insulin glargine using two primary data sources: (1) data from the IQVIA Canadian Drugstore and Hospital Purchases Audit representing all Canadian provinces except Newfoundland and Labrador, and (2) British Columbia health administrative data from Population Data BC. Interrupted time series analysis was used to quantify the results of two eras of biosimilars policies in British Columbia, including mandatory biosimilars use for new starters and subsequently mandated switching for all users, among individuals with inflammatory arthritis and psoriasis. RESULTS We found that prior to 2019 uptake of biosimilar infliximab, etanercept, and insulin glargine was low across Canada. Coinciding with the introduction of mandatory switching policies, there was a large increase in utilization thereafter in a number of provinces. In British Columbia, we determined that the introduction of mandatory switching among individuals with inflammatory arthritis and diabetes mellitus resulted in an increase in biosimilars utilization beyond what would have occurred if payers maintained new start policies only. CONCLUSION Government-mandated switching policies have the ability to greatly increase use of biosimilars even in the context of a multi-payer system. Although the ability to ascertain savings is limited due to the proprietary nature of drug pricing in Canada, the enhanced use of biosimilars will likely create a more favorable environment for price-based competition among pharmaceutical manufacturers. Future work should continue to examine the impact of mandatory switching on patients and prescribers as well as on the market for biologic drugs on a longer time horizon.
BackgroundA 2010 workforce survey revealed British Columbia was facing a shortage of rheumatologists and a consequent crisis of access to rheumatology care. Rheumatic diseases are chronic, and early intervention is crucial to prevent progression and mitigate systemic damage. Recognizing nurses may be able to perform aspects of rheumatology care and thereby “free up” rheumatologist time, the Ministry of Health introduced billing code G31060 to facilitate nurse-supported consultations for the “complex” rheumatology cases most in need of attention. The objective of this thesis is to evaluate the impact of introducing this new billing code and model of care on access to rheumatology care for the population of BC living with rheumatic disease.MethodsI conducted an interrupted time series analysis with a comparator using administrative health data on outpatient visits from Population Data BC. Patients with rheumatic diseases were identified using International Classification of Diseases codes and classified as those who received the intervention (i.e. nurse-supported rheumatologist care) or ‘status quo’ (i.e. rheumatologist care alone). Access was defined as 1) number of unique patients treated per month 2) number of service units billed per month. In sensitivity analyses I explored the impact of more restrictive definitions of intervention which required more “consistent” (at least once in every year) and “high-intensity” (at least 30 per year) billing of G31060.ResultsThe primary cohort included 128,726 patients with rheumatic disease, seen by 29 intervention and 17 comparator rheumatologists. No statistically significant effect change in level or trend of unique patients (pβ6=0.682 & pβ7=0.231) or service units (pβ6=0.744 & pβ7=0.419) attributable to the introduction of G31060 was detected in the primary analysis. Sensitivity analyses revealed statistically significant, increases in patients seen for rheumatologists billing “consistently” (62%) and with “high intensity” (168%) in April 2015 as compared to ‘status quo’. ConclusionThe introduction of G31060 does not appear to impact the number of service units billed per month, nor does it necessarily increase the number of patients seen. However, consistent and high-intensity users of G31060 appear to increase the number of unique patients seen per month.
Introduction: Currently, there are ongoing clinical trials for preventative treatments that aim to prevent and minimize the progression to RA in high risk individuals. However, preferences that drive people’s decision making in the context of a preventative treatment are unknown. With these clinical trials reporting their results within the next 2 years, this thesis aims to understand preferences of those who are at high risk of RA around preventative treatment and guide how these preferences can be best implemented in preventative treatment programs.Objectives:1) To identify important attributes for uptake of a preventative treatment program for those who are at high risk of RA, 2) To identify the value that is placed on these attributes through a discrete choice experiment (DCE), and 3) To predict the potential uptake of a preventative treatment options in those who are at high risk of RAMethods To determine the attributes that were important for the uptake of a preventative treatment program for those who are at high risk of RA, individuals with RA, first-degree relatives and rheumatologists were interviewed. These interviews were analyzed through a Framework Method. A DCE provided insight into whether those who are at high risk of RA would be willing to take preventative treatment. Results:The qualitative Framework analysis of patient, first-degree relative, and rheumatologist focus groups yielded five different attributes to be included in a DCE. Including the five treatment related attributes in the DCE demonstrated that first-degree relatives and RA patients preferred preventative treatments that had high risk reduction of RA, were orally administered, minor reversible side effects, moderate certainty in estimates, and were preferred by the health care provider. Predicted uptake of preventative treatments ranged from 51% to 92%, with oral methotrexate having the highest and infusion rituximab having the lowest.Conclusion:This thesis provides understanding around preferences, and subsequent trade-offs that an at risk individual might make when considering preventative treatment for RA. Through these trade-offs, the most important attributes of a preventative treatment program have been identified, and the likely uptake of potential preventative treatments have been estimated.