Does Country Or Continent Of Treatment Affect Outcome In Patients With Ruptured Cerebral Aneurysms?

Main Category: Neurology / Neuroscience
Also Included In: Cardiovascular / Cardiology;  Clinical Trials / Drug Trials
Article Date: 29 Apr 2008 - 0:00 PDT

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Subarachnoid hemorrhage (SAH) affects approximately 30,000 Americans every year, with 90 percent of all cases caused by cerebral aneurysms that have ruptured, the latter of which is referred to as aneurysmal SAH. Worldwide statistics vary greatly depending on the country and demographics, ranging from as low as 5.1 cases per 100,000 persons to as high as 19.6 cases per 100,000 persons, based on age-adjusted incidence studies. Statistics indicate that SAH results in fatality 30 to 40 percent of the time, and causes devastating neurological deficits an additional 25 percent of the time. There are several known factors that can influence outcome, including:

-- Patient's age

-- Patient's overall physical condition

-- Size, type, and location of the aneurysm

-- Type of treatment

-- Timeliness of treatment

"Theoretically, two variables that might likely affect SAH outcome are the country and/or continent of treatment, given the different treatment modalities utilized in various areas around the world," remarked R Loch Macdonald, MD, PhD, FRC, the author of this study. Dr. Macdonald analyzed data from 3,552 patients entered into randomized trials of a drug called tirilazad between 1991 and 1997. Patients were accrued from 162 neurosurgical centers in 21 countries from North America, Europe, Africa and Australia. Data was specific only to patients treated by neurosurgeons.

The results of this study, Does Country or Continent of Treatment Affect Outcome after Aneurysmal Subarachnoid Hemorrhage, will be presented by Dr. Macdonald, 4:30 to 4:44 p.m. on Monday, April 28, 2008, during the 76th Annual Meeting of the American Association of Neurological Surgeons in Chicago. Dr. Macdonald is the Keenan Endowed Chair in Surgery, head of the Division of Neurosurgery at St. Michael's Hospital, and professor of Surgery at the University of Toronto.

Recovery at three months post-SAH was assessed based on the Glasgow outcome scale used by the patients' physicians. This five-point scale is as follows: 1) Dead; 2) Vegetative; 3) Severely disabled; 4) Moderately disabled; and 5) Good recovery. For the purpose of this analysis, outcome was considered favorable if the patient made a good recovery or was only moderately disabled. An unfavorable outcome was judged to have occurred if the patient was severely disabled, was vegetative, or dead.

The effect of the country or continent where the patient was treated was assessed using statistical methods called univariable and multivariable logistic regression and proportional odds modeling before and after adjusting for factors significantly associated with outcome. Several multivariable models were constructed. The following outcomes were noted:

-- Country was not a significant predictor of outcome in any model (P>0.05).

-- There was variation in outcome between countries but it was due to differences in admission characteristics that influence outcome.

-- Since the number of patients from some countries was small, countries were grouped by continent. This provided more stable estimates and created an appropriate model for both logistic and proportional odds model.

-- Continent had no significant effect on outcome.

"Based on this in-depth analysis, despite variations in treatment between countries and continents in which the patient was treated, the conclusion was that where a patient was treated had little effect on outcome," stated Dr. Macdonald.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 7,200 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.

American Association of Neurological Surgeons (AANS)
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