Less Frequent Cholesterol Testing Puts Patients Heart Health at Risk, New Study Finds

March 2, 2023

Toronto, ON, March 2, 2023 – Patients treated by family physicians with lower clinical volumes and less frequent cholesterol testing have the highest rate of major cardiovascular events compared to physicians with the highest clinical volume, according to a new study led by a team from the Peter Munk Cardiac Centre (PMCC) at University Health Network (UHN), ICES, and Women’s College Hospital. 

Cardiovascular disease is the leading cause of death in North America. While research has established that the volume of patient visits to clinicians is associated with better health outcomes after heart attack or heart failure, it remained unclear whether patient volume at the primary care level—where most preventive care and testing takes place—could impact patient care and improve cardiovascular outcomes. 

“Adherence to blood cholesterol screening and testing is an important preventive cardiovascular care measure,” says lead author Jacob Udell, a cardiologist with the Department of Medicine at Women’s College Hospital and the University Health Network, Adjunct Scientist with ICES, and Clinician Scientist with the Women’s College Research Institute. “This study provides insight into the relationship between a family doctor’s patient visit volume and their adherence to cholesterol testing and treatment guidelines.”  

The study, published in the Canadian Journal of Cardiology, evaluated categories of clinical volume (defined as the annual number of visits made by patients to their family doctor) for approximately 10,000 primary care providers in Ontario, Canada. The researchers also examined a cohort of over 4.7 million adult residents of Ontario and found that: 

  • 84% underwent cholesterol testing at least once over 5 years, ranging from 73% among physicians with the lowest clinical volume to 86% among physicians with the highest volume. 
  • There was a 10.5% increase in the rate of cholesterol testing for every doubling of physician clinical volumes. 
  • Patients treated by the lowest volume physicians had the highest rate of major adverse cardiovascular events (MACE), compared to physicians with the highest clinical volume. MACE included cardiovascular death, nonfatal heart attack, and nonfatal stroke. 

It’s unclear whether busier primary care physicians perform more testing overall, or whether physicians with higher volume test more frequently because they adhere to higher-quality care standards and guidelines. The study found that 14% of patients in Ontario underwent annual cholesterol testing, with a two-fold increase in screening rates from the least to the busiest primary care provider—even after adjusting for patients who are routinely being tested as part of follow-up. 

The findings underscore the need for further research to explore the factors influencing testing frequency and adherence to guideline-recommended targets. 

“Improving the management of a patient’s cholesterol can ultimately reduce the risk of serious events, like heart attack or stroke,” says Dr. Udell. “At the system level, this can also save direct costs associated with in-patient care, cardiac rehabilitation and ambulatory services and indirect costs attributed to loss of work and premature death.” 

The study, “Primary care clinical volumes, cholesterol testing, and cardiovascular outcomes” was published in the Canadian Journal of Cardiology. 

The Peter Munk Cardiac Centre (PMCC) opened in 1997 through the generous support of Peter and Melanie Munk. A global leader in cardiovascular care, with internationally-renown medical expertise, PMCC has some of the best patient outcomes in the world and is home to many world firsts that span cardiac and vascular research and discoveries. Canada’s premier cardiac centre is part of the University Health Network (UHN) and located at the Toronto General Hospital, and the Toronto Western Hospital, in Toronto, Ontario, Canada. For more information, visit: www.petermunkcardiaccentre.ca 

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name. For the latest ICES news, follow us on Twitter: @ICESOntario 

About University Health Network  

University Health Network consists of Toronto General and Toronto Western Hospitals, the Princess Margaret Cancer Centre, Toronto Rehabilitation Institute, and The Michener Institute of Education at UHN. The scope of research and complexity of cases at University Health Network has made it a national and international source for discovery, education and patient care. It has the largest hospital-based research program in Canada, with major research in cardiology, transplantation, neurosciences, oncology, surgical innovation, arthritis, vision, infectious diseases, genomic medicine and rehabilitation medicine. University Health Network is a research hospital affiliated with the University of Toronto. For more information: www.uhn.ca 

About Women’s College Hospital  

For more than 100 years Women’s College Hospital (WCH) has been developing revolutionary advances in healthcare. Today, WCH is a world leader in health equity and Canada’s leading academic ambulatory hospital. It focuses on delivering innovative solutions that address Canada’s most pressing issues related to population health, patient experience and system costs. A multidisciplinary research institute, the Women’s College Research Institute (WCRI) is one of only a few hospital-based research institutes worldwide to focus on health equity. WCRI leads innovative, high impact health research that changes practice, changes policy, and changes lives. www.womenscollegehospital.ca 


Misty Pratt 
Senior Communications Officer, ICES 

Jordan Benadiba  
Manager, Public Affairs, WCH  
647 248 3680 

Rosa Kim 
Senior Public Affairs Advisor, UHN 
416 340 3895