On February 13th the BC-CfE hosted Dr. Michael Law for a Forefront Lecture entitled “What’s a quasi-experiment? And why should I care?” as part of a new Research Methods Series. Dr. Law is the Canada Research Chair in Access to Medicines at The University of British Columbia where his research focuses on pharmaceutical policy.
Speaking to healthcare providers and researchers, Dr. Law defined quasi-experiments as experiments that happen in the real world and they are “a way of finding randomness in the real world that you, as a researcher, can leverage and use to try and determine the causal effects of policies or interventions.” Administrative records, clinical data or surveys can all be used as data sources for quasi-experiments.
Dr. Law spoke of the rapidly growing interest in quasi-experiments and the research method of interrupted time series analysis. This research methodology saw more than 600 PubMed citations last year alone and has drawn significant attention from the research community over the past 10 years.
An example Law gave of interrupted time series analysis was the coverage for hepatitis C drugs here in BC. As we know when PharmaCare coverage for these drugs was first introduced in 2015, we can examine the infection levels and healthcare trends before and after this timepoint. This information can be used to better understand the impact of PharmaCare funding on drug uptake and infection rates over time.
While showcasing how quasi-experiments are a useful evaluation tool, he also pointed out some potential flaws in using these methods for particular healthcare conditions. For issues like the opioid crisis, he noted there is great difficulty, if not impossibility, in identifying the impact of single policy interventions. There are many interventions or variables, including local illicit fentanyl supply, the prevalence of supervised injection sites, or provincial policies such as declaring a public health emergency, which makes the analysis of this health data through quasi-experiments more challenging.
While randomized controlled trials remain the gold standard to advance clinical research and knowledge, Dr. Law argued that researchers should also be looking to quasi-experiments as a powerful evaluation method. It is one that can demonstrate causal effects, uses readily available data and is both time- and cost-effective.