Highlights of this issue
CMAJ 2000;162:1269
Differing opinions about tympanostomy tubes
Rates of bilateral myringotomy and tympanostomy tube insertion in children vary widely by region. Warren McIsaac and colleagues surveyed Ontario otolaryngologists to measure the extent of agreement on 17 potential indications for this surgery. Using 90% concordance as a definition of clinical agreement, the 121 eligible respondents agreed on only 6 of 17 factors and on the management of only 1 of 4 clinical vignettes. Given the lack of consensus, the authors suggest that it is time to revisit clinical practice guidelines for this procedure.
Anaphylactoid reactions to alteplase in stroke patients
Hypersensitivity reactions to recombinant tissue plasminogen activator (rt-PA, alteplase) occur in less that 0.02% of patients treated for acute myocardial infarction. Yet, among 105 patients given alteplase intravenously for acute stroke, 2 had lingual angioedema, which progressed to a fatal anaphylactoid reaction in 1. Michael Hill and colleagues review the 2 cases and possible mechanisms. Since submission of this article they have observed 2 further cases of angioedema. They warn that patients who are taking an angiotensin-converting-enzyme inhibitor may be at increased risk for angioedema with concomitant alteplase therapy.
Waiting lists: misinformation and mismanagement
There is a disturbing chasm between widely held views and the research evidence about waiting lists in Canada. Claudia Sanmartin and colleagues attribute this to confusion over terminology, differences in measures and methods, and a lack of awareness about management approaches. Frequently offered solutions such as introducing a two-tiered system and allocating additional public funding are not supported by evidence. The authors conclude that Canada needs a better infrastructure of information about waiting lists and their management. In a companion piece, Steven Lewis and colleagues comment on the woeful lack of information and point out that information and management defects are almost always prematurely diagnosed as financial shortages.
David Sackett discloses
"With the fear, hopelessness and trust I'd come to expect from my patients, she consented at once to take part in the trial. But by the time I completed her entry form I knew what I had to do. Blocking the view of the ward nurse, I took the syringe containing the study drug from the refrigerator, loaded a second syringe with penicillin G and injected her with both."
Through personal disclosure and discussion of "coal-face" commitment and the uncertainty principle, David Sackett begins a series of essays on why randomized controlled trials fail and why they needn't.
Selecting women for bone densitometry
The annual number of bone densitometry tests performed in Ontario increased from 34 402 to 165 630 between 1992 and 1997. Suzanne Cadarette and colleagues have developed and validated the Osteoporosis Risk Assessment Instrument (ORAI), a simple screening tool to assist clinicians in identifying women for whom bone densitometry is appropriate. By examining the data collected for the Canadian Multicentre Osteoporosis Study they selected clinical and demographic variables associated with low bone mineral density (BMD). They found that the ORAI, which uses age, weight and current estrogen use, accurately selected over 94% of study subjects with osteoporosis and 93% of those with low BMD for further testing, and selected less than 43% of those with normal BMD values.
© 2000 Canadian Medical Association or its licensors
