1989 to 1994

When is surgery required? Ask two surgeons the same question and you might get two different answers. That's because the judgement of the physician plays a large part in the decision to operate. It is a decision not made lightly since any surgery carries some element of risk. So anything that can make this decision more informed - that offers clearer insight into if, when and what kind of medical intervention works best, and solid evidence about the balance of risks and benefits - should be welcomed by both physicians and patients. CGAP offers just that.

CGAP - the Clinical Guidelines and Analysis Program - is a one year pilot program funded by Manitoba Health. It involves a collaboration between the College of Physicians and Surgeons of Manitoba and the Manitoba Centre for Health Policy and Evaluation (MCHPE) - a unique combination of research and clinical experience combined with data on the effectiveness and efficiency of medical interventions. The goal of CGAP is to synthesize this experience and data into clinical practice guidelines, to then encourage physicians to use these guidelines, and to evaluate the impact on patterns of practice. The ultimate aim is to improve the effectiveness and appropriateness of medical care in Manitoba.

Analysis of Manitoba data on patterns of medical practice is an important part of CGAP. Equally important is to study how closely our patterns of care mirror those known to work best. As an initial project for CGAP, we decided to study tonsillectomy. Several reasons made tonsillectomy ideal: it has long been one of the major causes of paediatric hospitalizations; the likelihood that children will undergo this surgery varies widely from one part of the province to another; and there were some concerns about the quality of care associated with this procedure.

The Tonsillectomy Review Panel was formed: Dr. Lindsay DuVal, an otolaryngologist in Winnipeg; Dr. Robert Smith, a Selkirk paediatrician; Dr. Don Klassen, a family practitioner in Winkler; as well as members of the CGAP team comprising Dr. John Mansfield, Ms. Mary Thliveris and Dr. Charlyn Black. What follows is a short review of what we learned from five years of data.

But before presenting our findings, it is important to comment that there are often non-surgical alternatives to removing tonsils, and that tonsillectomy itself is not an innocuous procedure. Like any surgery, it carries with it certain risks that range from death, to other complications from the anaesthetic or the surgery, to possible interference with the immune system. In order to determine whether a child should undergo tonsillectomy, the associated risks and benefits must be assessed. The clinician who recommends this (or any other surgical procedure) over non-surgical treatments must weigh the possibility of adverse consequences against potential benefits.

Patterns of Care
From 1989/90 to 1993/94, approximately 2,000 tonsillectomy procedures were conducted annually on Manitoba residents. There were wide variations in the number of tonsillectomies performed from one area to the next and from group to group.

  • Most tonsillectomies are performed in larger hospitals, with surgery conducted by specialist ENT (ear, nose and throat) surgeons, and anaesthesia provided by specialist anaesthetists. However, almost one-quarter of procedures are performed by non-specialist surgeons and/or anaesthetists, and roughly 6% take place in intermediate and small rural hospitals.

  • Females receive 39% more tonsillectomies than males, despite having lower rates of surgery in early childhood. The largest difference in rates occurs in adolescence.

  • Status Indians generally have lower rates of tonsillectomy in comparison to others and are less likely to receive surgery at younger ages, despite higher rates of illness.

  • Contrary to expectations, rates of surgery are 20% higher for rural residents than for people living in Winnipeg (fig.1), unexpected because Winnipeggers presumably have easier access to ENT surgeons.

  • Across Manitoba's eight health regions, the "highest rate region" had tonsillectomy rates 78% higher than Winnipeg's, which was the region with the lowest rate.

  • In the province, 21 areas can be identified where a single hospital provides the majority of tonsillectomies. Rates of surgery were over seven times higher in the area with the highest level compared to the lowest (fig.2). Since it is extremely unlikely that people in one area could have seven times the rate of severe tonsillitis than those in another, this large discrepancy is likely due to the different judgements made by physicians working at each hospital about the risks and benefits of tonsil surgery.
  • In short, it is likely that in some areas of Manitoba, residents are receiving more surgery than necessary. When we add the fact that areas served by ENT specialists - who are the most qualified to judge when tonsillectomy is required - typically have the lowest rates of surgery, that likelihood becomes even stronger.


    While most tonsillectomies in Manitoba are done by highly trained specialists, there is a small but significant portion of surgeries being performed by physicians and anaesthetists who do this procedure only a few times each year.

  • The number of physicians performing tonsillectomies has declined from 98 in 1990/91 to 73 in 1993/94. Most of the decline has occurred among physicians performing fewer than five cases per year.

  • In 1993/94, of the total number of physicians performing tonsillectomies, a small proportion - 26% - handled 83% of the procedures (fig.3); over half of all tonsillectomies were performed by eight surgeons.

  • A very large percentage (55%) of physicians perform nine or fewer procedures a year (fig.3); 34% less than five procedures.

    Significant change has recently occurred in patterns of tonsillectomy care, resulting in increased efficiency in hospital use. Over the past five years, two and three day stays have been declining, while one day and zero day (commonly called day surgery) stays have been increasing. The area of post-operative management is an area that requires careful consideration, particularly since children are prone to complications following surgery.

    These concerns not withstanding, recent changes in patterns of management of tonsillectomy have led to greatly improved efficiency in use of hospital days. Teaching and urban community hospitals now use "same day" admission practices (no overnight stay prior to surgery) for almost all cases. Increased efficiencies could be achieved if all hospitals performing tonsillectomies adopted a similar approach.


    The Clinical Guidelines and Analysis Program was developed to review and synthesize evidence, develop guidelines for practice based on an understanding of that evidence, review actual patterns of practice against the evidence and monitor changes in response to guidelines and data feedback strategies. It is clear that data analysis has a large role to play in these activities.

    Whenever it is shown that some physicians perform a particular procedure only a few times each year, quality of care becomes a concern. The Tonsillectomy Review Panel felt that it was important to stress that a sufficient number of tonsillectomies be performed yearly to ensure provider and institutional competence.

    Similarly, while it is becoming clear that a short stay after surgery may be appropriate, the high rates of same-day discharge of very young children from some small hospitals raised concern among members of the review panel. What "zero day stays" do not tell us is whether discharge occurred shortly after surgery or after several hours of monitoring. Since children undergoing tonsillectomy are prone to post-operative complications, in particular haemorrhage, a few hours of follow-up monitoring is a sensible precaution. Efficiency must be balanced against appropriate consideration of managing risk related to complications of surgery.

    Tonsillectomy has been and continues to be the most common paediatric surgical procedure. But rates of surgery have declined over time, likely due to changing understanding about indications for and benefits from the procedure. Recurrent throat infection is still the main reason for tonsillectomy, but that alone does not constitute an adequate basis for subjecting a child to surgery. Certain characteristics of the infection should be repeatedly observed, documented in the medical record and then assessed, always underscored by the question: is tonsillectomy going to provide enough benefits to offset the risks? It seems likely that in many cases this is not done. Research shows that even when these conditions are met, the amount of benefit conferred by tonsillectomy appears to be small. What's more, for less severely affected children, there are no good scientific studies that show evidence of any benefit, although this issue is currently under study.

    Another reason for surgery, and increasingly so in recent years, is obstruction - tonsils so large that they inhibit normal functioning of the throat. Just as for throat infections, when the benefits and risks are weighed, controversy exists about the merits of the procedure for anything less than severe obstruction.

    A clinical practice guideline for tonsillectomy has been distributed to all Manitoba practitioners. Evidence from other areas suggests that this alone will not lead to widespread acceptance. So while interest in clinical practice guidelines has never been greater, more creative approaches that involve information feedback will be more likely to engender the cooperation of all physicians. Part of the CGAP analyses provided information about which groups of physicians (and institutions) would likely gain from educational discussion of evidence about the risks and benefits of tonsillectomy. At the same time, the research provides important tools that can be used as part of the educational process.

    For instance, what should physicians conclude from variations in surgical rates? It certainly begs the question: which rate is right? Are residents being under-served or are they being over-served? If an institution learns that the residents it serves receive tonsillectomies at five times the rate of another institution - with no evident difference in health outcomes - the most obvious conclusion seems to be that fewer surgical procedures (which always include risk) are required. This relates to the experience of the physician-led Maine Medical Assessment Foundation, which found that review of population-based rates and sharing information with local groups of physicians was a remarkably powerful tool in facilitating change. Therefore, similar feedback to local hospital service areas represents an approach that would likely enhance the effectiveness of CGAP.

    Whether or not CGAP has been or will be effective in modifying physician behaviour, its unique ability to monitor its own effectiveness over time remains a distinct advantage. While development of the initial strategies for data analysis are fairly laborious, examining the same patterns in subsequent years will be relatively simple.

    The American College of Physicians recently proposed a new model for physicians to oversee medical care. Simply put, this model includes providing physicians with scientific evidence about what works for patients together with information about current practice. Manitoba's Clinical Guidelines and Analysis Program incorporates both these strategies. In doing so, it hopes to foster a cooperative, evidence-based approach to medical decision-making. It's an approach loaded with potential to improve health care in Manitoba.


    Summary written by RJ Currie, based on the report: Patterns of Tonsillectomy in Manitoba 1989-1993 (Analyses to support the Tonsillectomy Review Panel of the Clinical Guidelines and Analysis Program): by Charlyn Black, Sandra Peterson, John Mansfield and Mary Thliveris.

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