Published today in the British Medical Journal is a research article reporting a 34% relative increase in risk of hospitalization for acute kidney injury among patients started on a high potency statin (cholesterol lowering) drug compared with low potency statins, during the first 120 days of treatment.
Fortunately, the absolute frequency of hospitalization due to kidney injury in these circumstances is fairly rare. Of the approximately 7,000 patients per year started on high potency statins in Saskatchewan, 4 or 5 of them could end up with this kind of harmful effect.
The key message of the paper is that in circumstances where a high potency statin may not be required — for example in cholesterol lower for patients who have not had a prior heart attack or other cardiovascular disease — doctors and patients should carefully weigh the balance of risk and benefit when deciding on the type of cholesterol lowering drug to use. It may be that a low potency statin would be sufficient in many such cases. In the study, the following were considered high potency statins:
- rosuvastatin (e.g., Crestor) at doses of 10mg or higher
- atorvastatin (e.g., Lipitor) at doses 20mg or higher
- simvastatin (e.g., Zocor) at doses of 40 mg or more
We are fortunate to be able to do this kind of research in Canada. The study was conducted by a network of researchers and research centres across Canada called the Canadian Network for Observational Drug Effect Studies (CNODES). CNODES is is one of only 3 such networks around the world, and our is perhaps the most nimble. It was established two years ago through a grant from Health Canada and the Canadian Institutes for Health Research (CIHR) to conduct rapid-response analyses on the safety of prescription drugs that are in use in the Canadian market and for which safety concerns may have arisen through drug safety surveillance systems nationally or internationally.
CNODES responds to questions posed by the provincial or federal governments through a formal prioritization process. CNODES has participation from research centres in BC, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland and Labrador.
Participating researchers establish a common research protocol to address the drug safety questions they are given, which they then implement independently in their own provincial health data sets. Results are pooled nationally using a technique called meta-analysis to estimate the overall relationship between the drug and adverse outcome in question. CNODES has several other studies completed and under review by peer-reviewed journals and more for which the research is still underway.
I am the CNODES principal investigator for Saskatchewan; I’m Director of Measurement and Analysis with HQC and Adjunct Professor in the College of Medicine at the University of Saskatchewan. My co-investigators are Dr. David Blackburn (College of Pharmacy and Nutrition, U of S) and Dr. Lisa Lix (University of Manitoba and Adjunct Professor at U of S).
For the study published today, our team of analysts here at HQC participated in the national research team and undertook the data analysis using data provided for the study by the Saskatchewan Ministry of Health through a data sharing agreement with HQC. Part of the legislated mandate of HQC is to research and evaluate prescription drug use and practice in Saskatchewan and to promote research and education leading to improvement in the quality of health care in Saskatchewan.