PubMed Health⌕ Search

Biomedical subjects

Thomas E Feasby

Publications and source records attributed to Thomas E Feasby.

13 recordsLinked to original sources
PubMed2005

Statins are associated with better outcomes after carotid endarterectomy in symptomatic patients.

BACKGROUND AND PURPOSE: Statins have been associated with a reduction in mortality from noncardiac surgery. This study aimed to determine whether statin use on admission to hospital for carotid endarterectomy was associated with a reduction of in-hospital adverse outcomes. METHODS: Data describing patient characteristics, surgical indication, statin treatment, and in-hospital outcomes of death, ischemic stroke or death and cardiac outcomes were collected from a chart review of all patients (3360) undergoing carotid endarterectomy in Western Canada from January 2000 to December 2001. Outcomes of patients on statins versus those not on statins were compared using logistic regression to account for differences in patient characteristics, and propensity score methods to account for factors influencing patient allocation to statins. RESULTS: Eight hundred and fifteen of 2031 symptomatic patients and 665 of 1252 asymptomatic patients were on a statin at the time of hospital admission. Statin use by symptomatic patients was associated with reduced in-hospital mortality and in-hospital ischemic stroke or death, but not in-hospital cardiac outcomes (adjusted odds ratio 0.25 [CI, 0.07 to 0.90], 0.55 [CI, 0.32 to 0.95], 0.87 [CI, 0.49 to 1.54], respectively). The improvement in outcomes was robust when tested using propensity score matching. This association was not seen in asymptomatic patients on statins (adjusted odds ratio, in-hospital mortality 0.54 [CI, 0.13 to 2.24]; in-hospital ischemic stroke or death 1.34 [CI, 0.61 to 2.93]; in-hospital cardiac outcomes 1.37 [CI, 0.73 to 2.58]). CONCLUSIONS: These findings are suggestive of a protective effect of statin therapy in symptomatic patients pre-treated at the time of carotid endarterectomy, though this needs confirmation in a randomized controlled trial.

Aged↗
PubMed2005

Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data.

OBJECTIVES: Implementation of the International Statistical Classification of Disease and Related Health Problems, 10th Revision (ICD-10) coding system presents challenges for using administrative data. Recognizing this, we conducted a multistep process to develop ICD-10 coding algorithms to define Charlson and Elixhauser comorbidities in administrative data and assess the performance of the resulting algorithms. METHODS: ICD-10 coding algorithms were developed by "translation" of the ICD-9-CM codes constituting Deyo's (for Charlson comorbidities) and Elixhauser's coding algorithms and by physicians' assessment of the face-validity of selected ICD-10 codes. The process of carefully developing ICD-10 algorithms also produced modified and enhanced ICD-9-CM coding algorithms for the Charlson and Elixhauser comorbidities. We then used data on in-patients aged 18 years and older in ICD-9-CM and ICD-10 administrative hospital discharge data from a Canadian health region to assess the comorbidity frequencies and mortality prediction achieved by the original ICD-9-CM algorithms, the enhanced ICD-9-CM algorithms, and the new ICD-10 coding algorithms. RESULTS: Among 56,585 patients in the ICD-9-CM data and 58,805 patients in the ICD-10 data, frequencies of the 17 Charlson comorbidities and the 30 Elixhauser comorbidities remained generally similar across algorithms. The new ICD-10 and enhanced ICD-9-CM coding algorithms either matched or outperformed the original Deyo and Elixhauser ICD-9-CM coding algorithms in predicting in-hospital mortality. The C-statistic was 0.842 for Deyo's ICD-9-CM coding algorithm, 0.860 for the ICD-10 coding algorithm, and 0.859 for the enhanced ICD-9-CM coding algorithm, 0.868 for the original Elixhauser ICD-9-CM coding algorithm, 0.870 for the ICD-10 coding algorithm and 0.878 for the enhanced ICD-9-CM coding algorithm. CONCLUSIONS: These newly developed ICD-10 and ICD-9-CM comorbidity coding algorithms produce similar estimates of comorbidity prevalence in administrative data, and may outperform existing ICD-9-CM coding algorithms.

Algorithms↗
PubMed2004

Variations in rates of appropriate and inappropriate carotid endarterectomy for stroke prevention in 4 Canadian provinces.

BACKGROUND: Carotid endarterectomy (CE), when performed on appropriate patients, reduces the incidence of stroke, yet there are marked variations in rates of this procedure. We sought to determine reasons for the variation in CE rates in 4 Canadian provinces. METHODS: We identified all CEs performed in 4 Canadian provinces between January 2000 and December 2001, inclusive. From chart review and expert assessment, we determined the proportion of these procedures that were appropriate, inappropriate or of uncertain appropriateness, using the RAND/UCLA Appropriateness Method. We sought to determine the variation in rates by province and whether the variation was due to differences in type of hospital, surgical specialty or surgical volume. RESULTS: Overall, 1656 (52.3%) of the 3167 CEs studied were performed for appropriate indications. The proportions of appropriate procedures were 78.2% (176/225) in Saskatchewan, 58.7% (481/819) in Alberta, 49.1% (350/713) in Manitoba and 46.0% (649/1410) in British Columbia (p < 0.001 across provinces). Rates of appropriate procedures per 100 000 population ranged from 44.3 in Manitoba to 16.2 in Saskatchewan (p < 0.001 across provinces). CEs were more likely to be appropriate when performed by a neurosurgeon compared with all other surgeons (74.4% v. 49.4% were appropriate; p < 0.001), when performed by surgeons doing fewer than 31 procedures over 2 years compared with surgeons doing more than 31 (70.1% v. 49.5% were appropriate; p < 0.001) and when performed in hospitals doing fewer than 135 procedures per year compared with hospitals doing more than 135 (63.4% v. 49.1% were appropriate; p < 0.001). Overall, 10.3% of procedures were done for inappropriate reasons. INTERPRETATION: Our findings suggest some overuse (for inappropriate or uncertain indications) but also some underuse (low population rates in some regions). High rates of CE are associated with lower rates of appropriateness for both surgeons and hospitals. That 1 in 10 CEs is done inappropriately suggests the need for preoperative assessment of appropriateness.

Adult↗
PubMed2004

An audit tool for assessing the appropriateness of carotid endarterectomy.

BACKGROUND: To update appropriateness ratings for carotid endarterectomy using the best clinical evidence and to develop a tool to audit the procedure's use. METHODS: A nine-member expert panel drawn from all the Canadian Specialist societies that are involved in the care of patients with carotid artery disease, used the RAND Appropriateness Methodology to rate scenarios where carotid endarterectomy may be performed. A 9-point rating scale was used that permits the categorization of the use of carotid endarterectomy as appropriate, uncertain, or inappropriate. A descriptive analysis was undertaken of the final results of the panel meeting. A database and code were then developed to rate all carotid endarterectomies performed in a Western Canadian Health region from 1997 to 2001. RESULTS: All scenarios for severe symptomatic stenosis (70-99%) were determined to be appropriate. The ratings for moderate symptomatic stenosis (50-69%) ranged from appropriate to inappropriate. It was never considered appropriate to perform endarterectomy for mild stenosis (0-49%) or for chronic occlusions. Endarterectomy for asymptomatic carotid disease was thought to be of uncertain benefit at best. The majority of indications for the combination of endarterectomy either prior to, or at time of coronary artery bypass grafting were inappropriate. The audit tool classified 98.0% of all cases. CONCLUSIONS: These expert panel ratings, based on the best evidence currently available, provide a comprehensive and updated guide to appropriate use of carotid endarterectomy. The resulting audit tool can be downloaded by readers from the Internet and immediately used for hospital audits of carotid endarterectomy appropriateness.

Algorithms↗
PubMed2004

Importance of the imaging modality in decision making about carotid endarterectomy.

OBJECTIVE: To determine the influence of all possible imaging strategies on the appropriateness ratings for carotid endarterectomy, because less accurate noninvasive techniques are replacing contrast angiography, which was used in the major efficacy trials. METHODS: An expert panel, using appropriateness methodology, rated 203 scenarios where endarterectomy might be performed. Each scenario was rated where internal carotid artery stenosis was determined using five different imaging sources: 1) conventional angiography, 2) ultrasound carotid Doppler only, 3) CT (CTA) or MR (MRA) angiography only, 4) concordant results from two noninvasive carotid imaging studies, and 5) discordant results from two noninvasive studies. The scenarios deemed appropriate by conventional angiography were identified. The effect of the other imaging modalities on these results was examined. RESULTS: Thirty-three scenarios were identified as being appropriate. Concordant imaging results had no effect on appropriateness ratings in symptomatic carotid artery disease when compared with conventional angiography. Single noninvasive imaging techniques were deemed appropriate for investigation only in the presence of severe symptomatic stenosis. In all other scenarios, single noninvasive imaging and discordant results reduced the appropriateness rating of scenarios to either uncertain benefit or inappropriateness. The single appropriate scenario for asymptomatic carotid artery stenosis was where severe stenosis was determined by concordant noninvasive imaging or by CTA or MRA alone. CONCLUSION: It is important to take into account both the clinical scenario and the imaging modalities utilized to determine the degree of internal carotid artery stenosis in the clinical decision making surrounding carotid endarterectomy.

Angiography↗
PubMed2004

Factors influencing the decision to perform carotid endarterectomy.

Various interpretations of the indications for carotid endarterectomy exist. Physician knowledge as it relates to the decision to proceed or recommend carotid endarterectomy was investigated, using disaggregate discrete choice analysis. Canadian neurologists, neurosurgeons, vascular surgeons, and internists were surveyed. The degree of stenosis was most important, followed by symptoms, comorbid illness, and arterial imaging modality. No differences existed by specialty. Canadian physicians in four specialties are knowledgeable about results of randomized clinical trials for carotid endarterectomy.

Canada↗
PubMed2004

Carotid endarterectomy: a review.

BACKGROUND: Since the validation of carotid endarterectomy (CEA) as an effective means of stroke prevention, there has been renewed interest in its best indications and methods, as well as in how it compares to carotid angioplasty and stenting (CAS). This review examines these topics, as well as the investigation of carotid stenosis and the role of auditing and reporting CEA results. INVESTIGATION: Brain imaging with CT or MRI should be obtained in patients considered for CEA, in order to document infarction and rule out mass lesions. Carotid investigation begins with ultrasound and, if results agree with subsequent, good-quality MRA or CT angiography, treatment can be planned and catheter angiography avoided. An equally acceptable approach is to proceed directly from ultrasound to catheter angiography, which is still the gold-standard in carotid artery assessment. INDICATIONS: Appropriate patients for CEA are those symptomatic with transient ischemic attacks or nondisabling stroke due to 70-99% carotid stenosis; the maximum allowable stroke and death rate being 6%. Uncertain candidates for CEA are those with 50-69% symptomatic stenosis, and those with asymptomatic stenosis > or = 60% but, if selected carefully on the basis of additional risk factors (related to both the carotid plaque and certain patient characteristics), some will benefit from surgery. Asymptomatic patients will only benefit if surgery can be provided with exceptionally low major complication rates (3% or less). Inappropriate patients are those with less than 50% symptomatic or 60% asymptomatic stenosis, and those with unstable medical or neurological conditions. TECHNIQUES: Carotid endarterectomy can be performed with either regional or general anaesthesia and, for the latter, there are a number of monitoring techniques available to assess cerebral perfusion during carotid cross-clamping. While monitoring cannot be considered mandatory and no single monitoring technique has emerged as being clearly superior, EEG is most commonly used. "Eversion" endarterectomy is a variation in surgical technique, and there is some evidence that more widely practiced patch closure may reduce the acute risk of operative stroke and the longer-term risk of recurrent stenosis. CAROTID ANGIOPLASTY AND STENTING: Experience with this endovascular and less invasive procedure grows, and its technology continues to evolve. Some experienced therapists have reported excellent results in case series and a number of randomized trials are now underway comparing CAS to CEA. However, at this time it is premature to incorporate CAS into routine practice replacing CEA. AUDITING: It has been shown that auditing of CEA indications and results with regular feed-back to the operating surgeons can significantly improve the performance of this operation. Carotid endarterectomy auditing is recommended on both local and regional levels.

Carotid Artery Diseases↗
PubMed2002

Hospital and surgeon determinants of carotid endarterectomy outcomes.

BACKGROUND: Prior studies have found associations between surgeon and hospital case volumes and outcomes after carotid endarterectomy (CEA), but they have not simultaneously assessed the importance of a number of surgeon and hospital characteristics. OBJECTIVE: To simultaneously assess associations between hospital case volume, teaching status, clinical trial participation, and surgeon specialty and case volume and the outcome after CEA. DESIGN: Analysis of a large administrative data-base using logistic regression to correlate adverse outcomes after CEA with surgeon and hospital characteristics. SETTING AND PATIENTS: A Canadian administrative hospital discharge database of all patients undergoing CEA in fiscal years 1994 through 1997. MAIN OUTCOME MEASURES: In-hospital stroke and/or death. RESULTS: We found an inverse relationship between both hospital and surgeon case volumes and adverse outcomes. Teaching status had no association with outcome, but previous clinical trial participation predicted a better outcome. General surgeons fared worse than other specialists. Low-volume surgeons in low-volume hospitals had a relative risk of 3.5 for adverse outcomes compared with high-volume surgeons in high-volume hospitals. CONCLUSIONS: Several physician and hospital characteristics are determinants of outcome after CEA, but the negative effects of low hospital and surgeon case volumes, in particular, suggest that regionalization should be considered for CEA and that surgeons with low case volumes should not be performing CEA.

Aged↗
PubMed2002

Provincial carotid endarterectomy outcomes.

BACKGROUND: Outcomes must be measured as a first step toward improving performance. We sought to measure the national and provincial outcomes from carotid endarterectomy (CE) and explain provincial differences. METHODS: We analyzed a large Canada-wide administrative hospital discharge database of all patients, except those in Quebec, receiving CE in 1994-1997 and used logistic regression for risk adjustment to measure adverse outcomes nationally and by province. Our main outcome measures were in-hospital stroke and/or death. RESULTS: A total of 14,268 patients underwent CE in the years 1994-1997. The overall death rate was 1.3% and the combined stroke and/or death rate was 4.1%. There was a trend towards improvement over the four years. The provinces of Saskatchewan and Newfoundland had significantly higher adverse event rates for the risk-adjusted combined outcome measure. CONCLUSIONS: The outcome of CE in Canada is good and showed improvement over four years. However, significant differences in provincial outcomes were found. This suggests that regionalization across provincial boundaries may be needed to promote higher surgeon and hospital case volumes and thus improve outcomes.

Aged↗