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Size of family doctor’s practice not associated with quality of patient care: study


The quality of patient care provided by family physicians is mostly not compromised by larger patient load, says a new Ontario study from the Institute for Clinical Evaluative Sciences (ICES).

The study, published today* in the journal Annals of Family Medicine, showed as the number of patients under the care of a family physician (panel size) increased, the quality of cancer screening decreased slightly. However, the quality of chronic disease management was not compromised.

"We expected to observe lower quality of care at some point with larger panel sizes because we thought physicians would be unable to meet all their patients’ needs. However, the data do not demonstrate this," says Simone Dahrouge, the study’s lead author, an adjunct scientist at ICES and an assistant professor in the Department of Family Medicine at the University of Ottawa. "In fact, we observed only modest differences in quality of care associated with panel size, with no evidence of a threshold or shoulder beyond which quality dropped. These findings do not show evidence for policy measures such as thresholds or caps that reduce payments to providers with large patient loads.”

The researchers conducted a cross-sectional population-based study of Ontario family practices between 2008 and 2010. These included fee-for-service practices, as well as interprofessional and non-interprofessional capitated practices (a payment model where remuneration is highly influenced by the number of patients under the physician care rather than the number of services the patients seek), and accounted for a number of factors, including patient complexity.

Reviewing the records of 4,195 full-time family physicians with patient loads 1,200 or greater, the researchers extracted data from multiple linked health-related administrative databases for 8.3 million patients. They assessed 16 indicators of primary care quality covering five dimensions of care (cancer screening, chronic disease management, access, continuity, and comprehensiveness) in physician patient loads ranging from 1,200 to 3,900.

Among the study's findings were:

  • With increasing panel sizes (up to 3,900) patients had a slight reduction in their likelihood of being up-to-date on three cancer screenings compared to those receiving care from a physician with the lowest number of patients studied (relative reductions of 7.9 per cent, 5.9 per cent, and 4.6 per cent for cervical, colorectal, and breast cancer, respectively; or absolute reductions of 5 per cent, 2.7 per cent and 3 per cent, respectively).
  • Eight chronic care indicators representing adherence to recommended guidelines – ranging from eye exams for diabetic patients to medication for patients with congestive heart failure – showed no significant association with physician panel size.
  • Surprisingly, physicians with larger number of patients score higher on the likelihood that their patients with a new diagnosis of congestive heart failure had an echocardiogram; 75.5 per cent for the largest studied panel size compared to 69.4 per cent for the smallest panel size (a relative improvement of 8.1 per cent). The researchers note that this might be due to the fact that patients of physicians with larger panel sizes are more likely to receive care from specialists.
  • There was no consistent association between increasing panel size and use of hospital services in the urban setting, with larger panel sizes showing a roughly 11 per cent increase in the number of hospital admissions for ambulatory care-sensitive conditions (such as asthma, COPD, congestive heart failure or diabetes), but offset by a drop of similar magnitude (roughly 11 per cent) in the likelihood of non-urgent emergency room visits.
  • Physicians with larger practices were more likely to be male, foreign trained, and to work in urban practices. They were also more likely to serve immigrant patients and those from lower income groups.

The researchers caution that these results should not be interpreted as indicating that physicians can increase their panel size without significantly compromising quality. “It’s possible that physicians with larger panel sizes are able to compensate because they’ve adopted efficient processes, established structures that support quality, work in supportive organizational climate, or are just very quick. We also can’t disregard the likelihood that they may be working many more hours to compensate, although the number of hours alone can’t account for the results because we studied a greater than threefold range in panel size.” comments Dahrouge. “We can reasonably surmise that physicians who take on larger patient panels may be able to do so without compromising care quality, at least for the indicators we studied, because personal or practice characteristics allow them to provide effective and efficient care.”

“Primary care physician panel size and quality of care: a population-based study in Ontario, Canada,” was published today* in the journal Annals of Family Medicine.

Author block: Simone Dahrouge, William Hogg, Jaime Younger, Elizabeth Muggah, Grant Russell, Richard H Glazier.

*NOTE: This news release was updated January 11, 2016 to reflect a new publication date and title set by the journal.

The Institute for Clinical Evaluative Sciences (ICES) is an independent, non-profit organization 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. For the latest ICES news, follow us on Twitter: @ICESOntario


  • Kathleen Sandusky
  • Media Advisor, ICES
  • [email protected]
  • (o) 416-480-4780 or (c) 416-434-7763


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