Biomedical subjects

Kathryn M McDonald

Publications and source records attributed to Kathryn M McDonald.

At least 19 recordsLinked to original sources

PubMed2006

Effects of quality improvement strategies for type 2 diabetes on glycemic control: a meta-regression analysis.

CONTEXT: There have been numerous reports of interventions designed to improve the care of patients with diabetes, but the effectiveness of such interventions is unclear. OBJECTIVE: To assess the impact on glycemic control of 11 distinct strategies for quality improvement (QI) in adults with type 2 diabetes. DATA SOURCES AND STUDY SELECTION: MEDLINE (1966-April 2006) and the Cochrane Collaboration's Effective Practice and Organisation of Care Group database, which covers multiple bibliographic databases. Eligible studies included randomized or quasi-randomized controlled trials and controlled before-after studies that evaluated a QI intervention targeting some aspect of clinician behavior or organizational change and reported changes in glycosylated hemoglobin (HbA1c) values. DATA EXTRACTION: Postintervention difference in HbA1c values were estimated using a meta-regression model that included baseline glycemic control and other key intervention and study features as predictors. DATA SYNTHESIS: Fifty randomized controlled trials, 3 quasi-randomized trials, and 13 controlled before-after trials met all inclusion criteria. Across these 66 trials, interventions reduced HbA(1c) values by a mean of 0.42% (95% confidence interval [CI], 0.29%-0.54%) over a median of 13 months of follow-up. Trials with fewer patients than the median for all included trials reported significantly greater effects than did larger trials (0.61% vs 0.27%, P = .004), strongly suggesting publication bias. Trials with mean baseline HbA1c values of 8.0% or greater also reported significantly larger effects (0.54% vs 0.20%, P = .005). Adjusting for these effects, 2 of the 11 categories of QI strategies were associated with reductions in HbA(1c) values of at least 0.50%: team changes (0.67%; 95% CI, 0.43%-0.91%; n = 26 trials) and case management (0.52%; 95% CI, 0.31%-0.73%; n = 26 trials); these also represented the only 2 strategies conferring significant incremental reductions in HbA1c values. Interventions involving team changes reduced values by 0.33% more (95% CI, 0.12%-0.54%; P = .004) than those without this strategy, and those involving case management reduced values by 0.22% more (95% CI, 0.00%-0.44%; P = .04) than those without case management. Interventions in which nurse or pharmacist case managers could make medication adjustments without awaiting physician authorization reduced values by 0.80% (95% CI, 0.51%-1.10%), vs only 0.32% (95% CI, 0.14%-0.49%) for all other interventions (P = .002). CONCLUSIONS: Most QI strategies produced small to modest improvements in glycemic control. Team changes and case management showed more robust improvements, especially for interventions in which case managers could adjust medications without awaiting physician approval. Estimates of the effectiveness of other specific QI strategies may have been limited by difficulty in classifying complex interventions, insufficient numbers of studies, and publication bias.

Blood Glucose↗

PubMed2006

Systematic review: a century of inhalational anthrax cases from 1900 to 2005.

BACKGROUND: Mortality from inhalational anthrax during the 2001 U.S. attack was substantially lower than that reported historically. PURPOSE: To systematically review all published inhalational anthrax case reports to evaluate the predictors of disease progression and mortality. DATA SOURCES: MEDLINE (1966-2005), 14 selected journal indexes (1900-1966), and bibliographies of all retrieved articles. STUDY SELECTION: Case reports (in any language) between 1900 and 2005 that met predefined criteria. DATA EXTRACTION: Two authors (1 author for non-English-language reports) independently abstracted patient data. DATA SYNTHESIS: The authors found 106 reports of 82 cases of inhalational anthrax. Mortality was statistically significantly lower for patients receiving antibiotics or anthrax antiserum during the prodromal phase of disease, multidrug antibiotic regimens, or pleural fluid drainage. Patients in the 2001 U.S. attack were less likely to die than historical anthrax case-patients (45% vs. 92%; P < 0.001) and were more likely to receive antibiotics during the prodromal phase (64% vs. 13%; P < 0.001), multidrug regimens (91% vs. 50%; P = 0.027), or pleural fluid drainage (73% vs. 11%; P < 0.001). Patients who progressed to the fulminant phase had a mortality rate of 97% (regardless of the treatment they received), and all patients with anthrax meningoencephalitis died. LIMITATIONS: This was a retrospective case review of previously published heterogeneous reports. CONCLUSIONS: Despite advances in supportive care, fulminant-phase inhalational anthrax is usually fatal. Initiation of antibiotic or anthrax antiserum therapy during the prodromal phase is associated with markedly improved survival, although other aspects of care, differences in clinical circumstances, or unreported factors may contribute to this observed reduction in mortality. Efforts to improve early diagnosis and timely initiation of appropriate antibiotics are critical to reducing mortality.

Anthrax↗

PubMed2006

Reducing mortality from anthrax bioterrorism: strategies for stockpiling and dispensing medical and pharmaceutical supplies.

A critical question in planning a response to bioterrorism is how antibiotics and medical supplies should be stockpiled and dispensed. The objective of this work was to evaluate the costs and benefits of alternative strategies for maintaining and dispensing local and regional inventories of antibiotics and medical supplies for responses to anthrax bioterrorism. We modeled the regional and local supply chain for antibiotics and medical supplies as well as local dispensing capacity. We found that mortality was highly dependent on the local dispensing capacity, the number of individuals requiring prophylaxis, adherence to prophylactic antibiotics, and delays in attack detection. For an attack exposing 250,000 people and requiring the prophylaxis of 5 million people, expected mortality fell from 243,000 to 145,000 as the dispensing capacity increased from 14,000 to 420,000 individuals per day. At low dispensing capacities (<14,000 individuals per day), nearly all exposed individuals died, regardless of the rate of adherence to prophylaxis, delays in attack detection, or availability of local inventories. No benefit was achieved by doubling local inventories at low dispensing capacities; however, at higher dispensing capacities, the cost-effectiveness of doubling local inventories fell from 100,000 US dollars to 20,000 US dollars/life year gained as the annual probability of an attack increased from 0.0002 to 0.001. We conclude that because of the reportedly rapid availability of regional inventories, the critical determinant of mortality following anthrax bioterrorism is local dispensing capacity. Bioterrorism preparedness efforts directed at improving local dispensing capacity are required before benefits can be reaped from enhancing local inventories.

Anthrax↗

PubMed2006

Quality improvement strategies for hypertension management: a systematic review.

BACKGROUND: Care remains suboptimal for many patients with hypertension. PURPOSE: The purpose of this study was to assess the effectiveness of quality improvement (QI) strategies in lowering blood pressure. DATA SOURCES: MEDLINE, Cochrane databases, and article bibliographies were searched for this study. STUDY SELECTION: Trials, controlled before-after studies, and interrupted time series evaluating QI interventions targeting hypertension control and reporting blood pressure outcomes were studied. DATA EXTRACTION: Two reviewers abstracted data and classified QI strategies into categories: provider education, provider reminders, facilitated relay of clinical information, patient education, self-management, patient reminders, audit and feedback, team change, or financial incentives were extracted. DATA SYNTHESIS: Forty-four articles reporting 57 comparisons underwent quantitative analysis. Patients in the intervention groups experienced median reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) that were 4.5 mm Hg (interquartile range [IQR]: 1.5 to 11.0) and 2.1 mm Hg (IQR: -0.2 to 5.0) greater than observed for control patients. Median increases in the percentage of individuals achieving target goals for SBP and DBP were 16.2% (IQR: 10.3 to 32.2) and 6.0% (IQR: 1.5 to 17.5). Interventions that included team change as a QI strategy were associated with the largest reductions in blood pressure outcomes. All team change studies included assignment of some responsibilities to a health professional other than the patient's physician. LIMITATIONS: Not all QI strategies have been assessed equally, which limits the power to compare differences in effects between strategies. CONCLUSION: QI strategies are associated with improved hypertension control. A focus on hypertension by someone in addition to the patient's physician was associated with substantial improvement. Future research should examine the contributions of individual QI strategies and their relative costs.

Blood Pressure Determination↗

PubMed2005

Challenges in systematic reviews: synthesis of topics related to the delivery, organization, and financing of health care.

Some important health policy topics, such as those related to the delivery, organization, and financing of health care, present substantial challenges to established methods for evidence synthesis. For example, such reviews may ask: What is the effect of for-profit versus not-for-profit delivery of care on patient outcomes? Or, which strategies are the most effective for promoting preventive care? This paper describes innovative methods for synthesizing evidence related to the delivery, organization, and financing of health care. We found 13 systematic reviews on these topics that described novel methodologic approaches. Several of these syntheses used 3 approaches: conceptual frameworks to inform problem formulation, systematic searches that included nontraditional literature sources, and hybrid synthesis methods that included simulations to address key gaps in the literature. As the primary literature on these topics expands, so will opportunities to develop additional novel methods for performing high-quality comprehensive syntheses.

Decision Support Techniques↗

PubMed2004

Systematic review: surveillance systems for early detection of bioterrorism-related diseases.

BACKGROUND: Given the threat of bioterrorism and the increasing availability of electronic data for surveillance, surveillance systems for the early detection of illnesses and syndromes potentially related to bioterrorism have proliferated. PURPOSE: To critically evaluate the potential utility of existing surveillance systems for illnesses and syndromes related to bioterrorism. DATA SOURCES: Databases of peer-reviewed articles (for example, MEDLINE for articles published from January 1985 to April 2002) and Web sites of relevant government and nongovernment agencies. STUDY SELECTION: Reports that described or evaluated systems for collecting, analyzing, or presenting surveillance data for bioterrorism-related illnesses or syndromes. DATA EXTRACTION: From each included article, the authors abstracted information about the type of surveillance data collected; method of collection, analysis, and presentation of surveillance data; and outcomes of evaluations of the system. DATA SYNTHESIS: 17,510 article citations and 8088 government and nongovernmental Web sites were reviewed. From these, the authors included 115 systems that collect various surveillance reports, including 9 syndromic surveillance systems, 20 systems collecting bioterrorism detector data, 13 systems collecting influenza-related data, and 23 systems collecting laboratory and antimicrobial resistance data. Only the systems collecting syndromic surveillance data and detection system data were designed, at least in part, for bioterrorism preparedness applications. Syndromic surveillance systems have been deployed for both event-based and continuous bioterrorism surveillance. Few surveillance systems have been comprehensively evaluated. Only 3 systems have had both sensitivity and specificity evaluated. LIMITATIONS: Data from some existing surveillance systems (particularly those developed by the military) may not be publicly available. CONCLUSIONS: Few surveillance systems have been specifically designed for collecting and analyzing data for the early detection of a bioterrorist event. Because current evaluations of surveillance systems for detecting bioterrorism and emerging infections are insufficient to characterize the timeliness or sensitivity and specificity, clinical and public health decision making based on these systems may be compromised.

Bioterrorism↗

PubMed2004

Impacts of informal caregiver availability on long-term care expenditures in OECD countries.

OBJECTIVE: To quantify the effects of informal caregiver availability and public funding on formal long-term care (LTC) expenditures in developed countries. DATA SOURCE/STUDY SETTING: Secondary data were acquired for 15 Organization for Economic Cooperation and Development (OECD) countries from 1970 to 2000. STUDY DESIGN: Secondary data analysis, applying fixed- and random-effects models to time-series cross-sectional data. Outcome variables are inpatient or home heath LTC expenditures. Key explanatory variables are measures of the availability of informal caregivers, generosity in public funding for formal LTC, and the proportion of the elderly population in the total population. DATA COLLECTION/EXTRACTION METHOD: Aggregated macro data were obtained from OECD Health Data, United Nations Demographic Yearbooks, and U.S. Census Bureau International Data Base. PRINCIPAL FINDINGS: Most of the 15 OECD countries experienced growth in LTC expenditures over the study period. The availability of a spouse caregiver, measured by male-to-female ratio among the elderly, is associated with a $28,840 (1995 U.S. dollars) annual reduction in formal LTC expenditure per additional elderly male. Availability of an adult child caregiver, measured by female labor force participation and full-time/part-time status shift, is associated with a reduction of $310 to $3,830 in LTC expenditures. These impacts on LTC expenditure vary across countries and across time within a country. CONCLUSIONS: The availability of an informal caregiver, particularly a spouse caregiver, is among the most important factors explaining variation in LTC expenditure growth. Long-term care policies should take into account behavioral responses: decreased public funding in LTC may lead working women to leave the labor force to provide more informal care.

Adult↗

PubMed2004

Evaluating detection and diagnostic decision support systems for bioterrorism response.

We evaluated the usefulness of detection systems and diagnostic decision support systems for bioterrorism response. We performed a systematic review by searching relevant databases (e.g., MEDLINE) and Web sites for reports of detection systems and diagnostic decision support systems that could be used during bioterrorism responses. We reviewed over 24,000 citations and identified 55 detection systems and 23 diagnostic decision support systems. Only 35 systems have been evaluated: 4 reported both sensitivity and specificity, 13 were compared to a reference standard, and 31 were evaluated for their timeliness. Most evaluations of detection systems and some evaluations of diagnostic systems for bioterrorism responses are critically deficient. Because false-positive and false-negative rates are unknown for most systems, decision making on the basis of these systems is seriously compromised. We describe a framework for the design of future evaluations of such systems.

Bioterrorism↗

PubMed2003

Changes in rates of autopsy-detected diagnostic errors over time: a systematic review.

CONTEXT: Substantial discrepanies exist between clinical diagnoses and findings at autopsy. Autopsy may be used as a tool for quality management to analyze diagnostic discrepanies. OBJECTIVE: To determine the rate at which autopsies detect important, clinically missed diagnoses, and the extent to which this rate has changed over time. DATA SOURCES: A systematic literature search for English-language articles available on MEDLINE from 1966 to April 2002, using the search terms autopsy, postmortem changes, post-mortem, postmortem, necropsy, and posthumous, identified 45 studies reporting 53 distinct autopsy series meeting prospectively defined criteria. Reference lists were reviewed to identify additional studies, and the final bibliography was distributed to experts in the field to identify missing or unpublished studies. STUDY SELECTION: Included studies reported clinically missed diagnoses involving a primary cause of death (major errors), with the most serious being those likely to have affected patient outcome (class I errors). DATA EXTRACTION: Logistic regression was performed using data from 53 distinct autopsy series over a 40-year period and adjusting for the effects of changes in autopsy rates, country, case mix (general autopsies; adult medical; adult intensive care; adult or pediatric surgery; general pediatrics or pediatric inpatients; neonatal or pediatric intensive care; and other autopsy), and important methodological features of the primary studies. DATA SYNTHESIS: Of 53 autopsy series identified, 42 reported major errors and 37 reported class I errors. Twenty-six autopsy series reported both major and class I error rates. The median error rate was 23.5% (range, 4.1%-49.8%) for major errors and 9.0% (range, 0%-20.7%) for class I errors. Analyses of diagnostic error rates adjusting for the effects of case mix, country, and autopsy rate yielded relative decreases per decade of 19.4% (95% confidence interval [CI], 1.8%-33.8%) for major errors and 33.4% (95% [CI], 8.4%-51.6%) for class I errors. Despite these decreases, we estimated that a contemporary US institution (based on autopsy rates ranging from 100% [the extrapolated extreme at which clinical selection is eliminated] to 5% [roughly the national average]), could observe a major error rate from 8.4% to 24.4% and a class I error rate from 4.1% to 6.7%. CONCLUSION: The possibility that a given autopsy will reveal important unsuspected diagnoses has decreased over time, but remains sufficiently high that encouraging ongoing use of the autopsy appears warranted.

Autopsy↗

PubMed2002

Effectiveness and cost-effectiveness of implantable cardioverter defibrillators in the treatment of ventricular arrhythmias among medicare beneficiaries.

PURPOSE: The implantable cardioverter defibrillator has been assessed in randomized trials, but the generalizability of trial results to broader clinical settings is unclear. Our purpose was to evaluate the outcomes and costs of defibrillator use in an unselected population. SUBJECTS AND METHODS: We identified 125,892 Medicare patients who were discharged between 1987 and 1995 after hospitalization with a primary diagnosis of ventricular tachycardia or ventricular fibrillation, 7789 of whom (6.2%) received a defibrillator. We used a multivariable propensity score that included patient and hospital characteristics to match pairs of patients, in which one patient received a defibrillator and the other did not. We compared mortality and costs in these 7612 matched pairs during 8 years of follow-up. RESULTS: Patients who received a defibrillator were more likely to be younger, white, male, and urban dwelling, and to have ischemic heart disease, heart failure, or a history of ventricular fibrillation. In the matched-pairs analysis, those who received a defibrillator had significantly lower mortality: 11% versus 19% at 1 year (odds ratio [OR] = 0.57; 95% confidence interval [CI]: 0.51 to 0.63), 20% versus 30% at 2 years (OR = 0.66; 95% CI: 0.60 to 0.72), and 28% versus 39% at 3 years (OR = 0.70; 95% CI: 0.63 to 0.77). These patients also had lower mortality at 8 years (P = 0.0001), although this advantage over patients who received medical treatment only decreased over time. Expenditures among defibrillator recipients were consistently higher, with a cost-effectiveness ratio of $78,400 per life-year gained. CONCLUSION: The use of implantable defibrillators was associated with significantly lower mortality and higher costs, whereas the cost-effectiveness was higher than many, but not all, generally accepted therapies.

Aged↗

PubMed2002

Evidence-based practice for mere mortals: the role of informatics and health services research.

The poor translation of evidence into practice is a well-known problem. Hopes are high that information technology can help make evidence-based practice feasible for mere mortal physicians. In this paper, we draw upon the methods and perspectives of clinical practice, medical informatics, and health services research to analyze the gap between evidence and action, and to argue that computing systems for bridging this gap should incorporate both informatics and health services research expertise. We discuss 2 illustrative systems--trial banks and a web-based system to develop and disseminate evidence-based guidelines (alchemist)--and conclude with a research and training agenda.

Evidence-Based Medicine↗

PubMed2002

Risk of sudden versus nonsudden cardiac death in patients with coronary artery disease.

BACKGROUND: Patients at high risk of sudden cardiac death, yet at low risk of nonsudden death, might be ideal candidates for antiarrhythmic drugs or devices. Most previous studies of prognostic markers for sudden cardiac death have ignored the competitive risk of nonsudden cardiac death. The goal of the present study was to evaluate the ability of clinical factors to distinguish the risks of sudden and nonsudden cardiac death. METHODS: We identified all deaths during a 3.3-year follow-up of 30,680 patients discharged alive after admission to the cardiac care unit of a Seattle hospital. Detailed chart reviews were conducted on 1093 subsequent out-of-hospital sudden deaths, 973 nonsudden cardiac deaths, and 442 randomly selected control patients. RESULTS: Patients who died in follow-up (suddenly or nonsuddenly) were significantly different for many clinical factors from control patients. In contrast, patients with sudden cardiac death were insignificantly different for most clinical characteristics from patients with nonsudden cardiac death. The mode of death was 20% to 30% less likely to be sudden in women, patients who had angioplasty or bypass surgery, and patients prescribed beta-blockers. The mode of death was 20% to 30% more likely to be sudden in patients with heart failure, frequent ventricular ectopy, or a discharge diagnosis of acute myocardial infarction. A multivariable model had only modest predictive capacity for mode of death (c-index of 0.62). CONCLUSION: Standard clinical evaluation is much better at predicting overall risk of death than at predicting the mode of death as sudden or nonsudden.

Adrenergic beta-Antagonists↗

PubMed2002

Utilization and outcomes of the implantable cardioverter defibrillator, 1987 to 1995.

BACKGROUND: The patterns of adoption of the implantable cardioverter defibrillator (ICD) and the outcomes of its use have not been well documented in general, unselected populations. The purpose of this study was to document the impact of the ICD in widespread clinical practice. METHODS: We identified ICD recipients by use of the hospital discharge databases of Medicare beneficiaries for 1987 through 1995 and of California residents for 1991 through 1995. The index admission for each patient was linked to previous and subsequent admissions and to mortality files to create a longitudinal patient profile. RESULTS: The rate of ICD implantations increased >10-fold between 1987 and 1995, as both the number of hospitals performing the procedure and the volume of ICD implantations per hospital rose. Mortality rates within 30 days of ICD implantation decreased from 6.0% to 1.9%, and mortality rates within 1 year fell from 19.3% to 11.4%. Surgical interventions to revise or replace the ICD within the first year remained about 5%, however, and cumulative expenditures at 1 year ($46,000-$51,000) changed very little. ICD implantation rates varied >3-fold among different regions of the United States. CONCLUSIONS: ICD use has expanded markedly during the study period, with improved mortality rates, but medical expenditures and rates of surgical revision remain high for ICD recipients.

Age Factors↗

PubMed2002

Life after a ventricular arrhythmia.

BACKGROUND: There are few data from community-based evaluations of outcomes after a life-threatening ventricular arrhythmia (LTVA). We evaluated patients' quality of life (QOL) and medical costs after hospitalization and treatment for their first episode of an LTVA. METHODS: We prospectively evaluated QOL by use of the Duke Activity Status Index (DASI), Medical Outcomes Study SF-36 mental health and vitality scales, the Cardiac Arrhythmia Suppression Trial (CAST) symptom scale, and resource use in patients discharged after a first episode of an LTVA in a managed care population of 2.4 million members. RESULTS: We enrolled 264 subjects with new cases of LTVA. Although functional status initially decreased compared with self-reports of pre-event functional status, both functional status and symptom levels improved significantly during the study period. These improvements were greater in patients receiving an implantable cardioverter defibrillator (ICD) than in patients receiving amiodarone. Ratings of mental health and vitality were not significantly different between the treatment groups and did not change significantly during follow-up. The total 2-year medical costs were higher for patients receiving an ICD than for patients receiving amiodarone, despite lower costs during the follow-up period for the patients receiving an ICD. CONCLUSIONS: New onset of an LTVA has a substantial negative initial impact on QOL. With therapy, most patients have improvements in their QOL and symptom level, possibly more so after treatment with an ICD. The costs of treating these patients are very high.

Aged↗

PubMed2002

Trends in hospital treatment of ventricular arrhythmias among Medicare beneficiaries, 1985 to 1995.

BACKGROUND: Treatment options for patients with ventricular arrhythmias have undergone major changes in the last 2 decades. Trends in use of invasive procedures, clinical outcomes, and expenditures have not been well documented. METHODS: We used administrative databases of Medicare beneficiaries from 1985 to 1995 to identify patients hospitalized with ventricular arrhythmias. We created a longitudinal patient profile by linking the index admission with all earlier and subsequent admissions and with death records. RESULTS: Approximately 85,000 patients aged > or =65 years went to hospitals in the United States with ventricular arrhythmias each year, and about 20,000 lived to admission. From 1987 to 1995, the use of electrophysiology studies and implantable cardioverter defibrillators in patients who were hospitalized grew substantially, from 3% to 22% and from 1% to 13%, respectively. Hospital expenditures rose 8% per year, primarily because of the increased use of invasive procedures. Survival improved, particularly in the medium term, with 1-year survival rates increasing between 1987 and 1994 from 52.9% to 58.3%, or half a percentage point each year. CONCLUSION: Survival of patients who sustain a ventricular arrhythmia is poor, but improving. For patients who are admitted, more intensive treatment has been accompanied by increased hospital expenditures.

Aged↗

PubMed2002

Overview of randomized trials of antiarrhythmic drugs and devices for the prevention of sudden cardiac death.

BACKGROUND: Sudden cardiac death is a prominent feature of the natural history of heart disease. The efficacy of antiarrhythmic drugs and devices in preventing sudden death and reducing total mortality is uncertain. METHODS: We reviewed randomized trials and quantitative overviews of type I and type III antiarrhythmic drugs. We also reviewed the randomized trials of implantable cardioverter defibrillators and combined these outcomes in a quantitative overview. RESULTS: Randomized trials of type I antiarrhythmic agents used as secondary prevention after myocardial infarction show an overall 21% increase in mortality rate. Randomized trials of amiodarone suggest a 13% to 19% decrease in mortality rate, and sotalol has been effective in several small trials. Trials of pure type III agents, however, have shown no mortality benefit. An overview of implantable defibrillator trials shows a 24% reduction in mortality rate (CI 15%-33%) compared with alternative therapy, most often amiodarone. CONCLUSION: Amiodarone is effective in reducing the total mortality rate by 13% to 19%, and the implantable defibrillator reduces the mortality rate by a further 24%.

Aged↗

PubMed2002

Management of ventricular arrhythmias in diverse populations in California.

BACKGROUND: The use of coronary angiography and revascularization is lower than expected among black patients. It is uncertain whether use of other cardiac procedures also varies according to race and ethnicity and whether outcomes are affected. METHODS: We analyzed discharge abstracts from all nonfederal hospitals in California of patients hospitalized for a primary diagnosis of ventricular tachycardia or ventricular fibrillation between 1992 and 1994. We compared mortality rates and use of electrophysiologic study (EPS) and implantable cardioverter-defibrillator (ICD) procedures according to the race and ethnicity of the patient. RESULTS: Among 8713 patients admitted with ventricular tachycardia or ventricular fibrillation, 29% (n = 2508) had a subsequent EPS procedure, and 9% (n = 818) had an ICD implanted. After controlling for potential confounding factors, we found that black patients were significantly less likely than white patients to undergo EPS (odds ratio 0.72, CI 0.56-0.92) or ICD implantation (odds ratio 0.39, CI 0.25-0.60). Blacks discharged alive from the initial hospital admission had higher mortality rates over the next year than white patients, even after controlling for multiple confounding risk factors (risk ratio 1.18, CI 1.03-1.36). The use of EPS and ICD procedures was also significantly affected by several other factors, most notably by on-site procedure availability but also by age, sex, and insurance status. CONCLUSIONS: In a large population of patients hospitalized for ventricular arrhythmia, blacks had significantly lower rates of utilization for EPS and ICD procedures and higher subsequent mortality rates.

Black or African American↗

PubMed2002

Effect of risk stratification on cost-effectiveness of the implantable cardioverter defibrillator.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) effectively prevent sudden cardiac death, but selection of appropriate patients for implantation is complex. We evaluated whether risk stratification based on risk of sudden cardiac death alone was sufficient to predict the effectiveness and cost-effectiveness of the ICD. METHODS: We developed a Markov model to evaluate the cost-effectiveness of ICD implantation compared with empiric amiodarone treatment. The model incorporated mortality rates from sudden and nonsudden cardiac death, noncardiac death and costs for each treatment strategy. We based our model inputs on data from randomized clinical trials, registries, and meta-analyses. We assumed that the ICD reduced total mortality rates by 25%, relative to use of amiodarone. RESULTS: The relationship between cost-effectiveness of the ICD and the total annual cardiac mortality rate is U-shaped; cost-effectiveness becomes unfavorable at both low and high total cardiac mortality rates. If the annual total cardiac mortality rate is 12%, the cost-effectiveness of the ICD varies from $36,000 per quality-adjusted life-year (QALY) gained when the ratio of sudden cardiac death to nonsudden cardiac death is 4 to $116,000 per QALY gained when the ratio is 0.25. CONCLUSIONS: The cost-effectiveness of ICD use relative to amiodarone depends on total cardiac mortality rates as well as the ratio of sudden to nonsudden cardiac death. Studies of candidate diagnostic tests for risk stratification should distinguish patients who die suddenly from those who die nonsuddenly, not just patients who die suddenly from those who live.

Amiodarone↗