Andrew Cheung, MD; Thérèse A. Stukel, PhD; David A. Alter, MD, PhD; Richard H. Glazier, MD, MPH; Vicki Ling, MSc; Xuesong Wang, MSc; Baiju R. Shah, MD, PhD
Disclaimer: The opinions, results, and conclusions reported in this article are those of the authors. No endorsement by the Canadian Institutes of Health Research, the Institute for Clinical Evaluative Sciences, the Ontario Ministry of Health and Long-Term Care, or the Canadian Institute for Health Information is intended or should be inferred.
Acknowledgment: The authors thank Brogan, Ottawa, Ontario, for use of its Drug Product and Therapeutic Class Database. The study relied on data and information compiled and provided by the Canadian Institute for Health Information.
Grant Support: Funding for the study was provided by a Foundation Grant (FDN143303) and an Emerging Team Grant in Applied Health Services and Policy Research (ETG92248) from the Canadian Institutes of Health Research. Dr. Alter is a Career Investigator with the Heart and Stroke Foundation of Ontario and holds a Research Chair in Cardiovascular Metabolic Rehabilitation at the University Health Network-Toronto Rehabilitation Institute. Dr. Glazier is supported as a clinician-scientist in the Department of Family and Community Medicine at the University of Toronto and at St. Michael's Hospital. The Institute for Clinical Evaluative Sciences is a nonprofit research institute funded by the Ontario Ministry of Health and Long-Term Care.
Disclosures: Authors have disclosed no conflicts of interest. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M16-1056.
Editors' Disclosures: Christine Laine, MD, MPH, Editor in Chief, reports that she has no financial relationships or interests to disclose. Darren B. Taichman, MD, PhD, Executive Deputy Editor, reports that he has no financial relationships or interests to disclose. Cynthia D. Mulrow, MD, MSc, Senior Deputy Editor, reports that she has no relationships or interests to disclose. Deborah Cotton, MD, MPH, Deputy Editor, reports that she has no financial relationships or interest to disclose. Jaya K. Rao, MD, MHS, Deputy Editor, reports that she has stock holdings/options in Eli Lilly and Pfizer. Sankey V. Williams, MD, Deputy Editor, reports that he has no financial relationships or interests to disclose. Catharine B. Stack, PhD, MS, Deputy Editor for Statistics, reports that she has stock holdings in Pfizer and Johnson & Johnson.
Reproducible Research Statement:Study protocol and data set: Not available. Statistical code: Available from Dr. Shah (e-mail, email@example.com).
Requests for Single Reprints: Baiju R. Shah, MD, PhD, Institute for Clinical Evaluative Sciences, G106 – 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada.
Current Author Addresses: Dr. Cheung: Department of Medicine, McMaster University, Health Sciences Centre, 3W10, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.
Drs. Stukel, Alter, Glazier, and Shah; Ms. Ling; and Ms. Wang: Institute for Clinical Evaluative Sciences, G106 – 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada.
Author Contributions: Conception and design: A. Cheung, T.A. Stukel, D.A. Alter, R.H. Glazier, B.R. Shah.
Analysis and interpretation of the data: A. Cheung, T.A. Stukel, D.A. Alter, R.H. Glazier, V. Ling, X. Wang, B.R. Shah.
Drafting of the article: A. Cheung.
Critical revision of the article for important intellectual content: T.A. Stukel, D.A. Alter, R.H. Glazier, B.R. Shah.
Final approval of the article: A. Cheung, T.A. Stukel, D.A. Alter, R.H. Glazier, V. Ling, X. Wang, B.R. Shah.
Statistical expertise: T.A. Stukel.
Obtaining of funding: T.A. Stukel.
A relationship between higher patient volume and both better quality of care and better outcomes has been shown for many acute care conditions. Whether a volume–quality relationship exists for the outpatient management of chronic diseases is uncertain.
To explore the association between primary care physician volume and quality of diabetes care.
The study was conducted using linked population-based health care administrative data in Ontario, Canada.
1 018 647 adults with diabetes in 2011 who received care from 9014 primary care physicians. Two measures of volume were ascertained for each physician: overall ambulatory volume (representing time available to devote to chronic disease management during patient encounters) and diabetes-specific volume (representing disease-specific expertise).
Quality of care was measured over a 2-year period using 6 indicators: disease monitoring (eye examination, hemoglobin A1c testing, and low-density lipoprotein cholesterol testing), prescribing appropriate medications (angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers and statins), and adverse clinical outcomes (emergency department visits for hypoglycemia or hyperglycemia).
Higher overall ambulatory volume was associated with lower rates of appropriate disease monitoring and medication prescription. In contrast, higher diabetes-specific volume was associated with better quality of care across all 6 indicators.
Only a select set of quality indicators and potential confounders could be ascertained from available data.
Primary care physicians with busier ambulatory patient practices delivered lower-quality diabetes care, but those with greater diabetes-specific experience delivered higher-quality care. These findings show that relationships between physician volume and quality can be extended from acute care to outpatient chronic disease care. Health policies or programs to support physicians with a low volume of patients with diabetes may improve care.
Canadian Institutes of Health Research.
Cheung A, Stukel TA, Alter DA, et al. Primary Care Physician Volume and Quality of Diabetes Care: A Population-Based Cohort Study. Ann Intern Med. [Epub ahead of print 13 December 2016]166:240–247. doi: 10.7326/M16-1056
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Published: Ann Intern Med. 2017;166(4):240-247.
Published at www.annals.org on 13 December 2016
Cardiology, Coronary Risk Factors, Diabetes, Endocrine and Metabolism.
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