Search PubMed⌕ Search

Biomedical subjects

D B Mark

Publications and source records attributed to D B Mark.

At least 73 records · Page 4Linked to original sources
PubMed1997

Relationship between physician and hospital coronary angioplasty volume and outcome in elderly patients.

BACKGROUND: With the expectation that physicians who perform larger numbers of coronary angioplasty procedures will have better outcomes, the American College of Cardiology/ American Heart Association guidelines recommend minimum physician volumes of 75 procedures per year. However, there is little empirical data to support this recommendation. METHODS AND RESULTS: We examined in-hospital bypass surgery and death after angioplasty according to 1992 physician and hospital Medicare procedure volume. In 1992, 6115 physicians performed angioplasty on 97,478 Medicare patients at 984 hospitals. The median numbers of procedures performed per physician and per hospital were 13 (interquartile range, 5 to 25) and 98 (interquartile range, 40 to 181), respectively. With the assumption that Medicare patients composed one half to one third of all patients undergoing angioplasty, these median values are consistent with an overall physician volume of 26 to 39 cases per year and an overall hospital volume of 196 to 294 cases per year. After adjusting for age, sex, race, acute myocardial infarction, and comorbidity, low-volume physicians were associated with higher rates of bypass surgery (P < .001) and low-volume hospitals were associated with higher rates of bypass surgery and death (P < .001). Improving outcomes were seen up to threshold values of 75 Medicare cases per physician and 200 Medicare cases per hospital. CONCLUSIONS: More than 50% of physicians and 25% of hospitals performing coronary angioplasty in 1992 were unlikely to have met the minimum volume guidelines first published in 1988, and these patients had worse outcomes. While more recent data are required to determine whether the same relationships persist after the introduction of newer technologies, this study suggests that adherence to minimum volume standards by physicians and hospitals will lead to better outcomes for elderly patients undergoing coronary angioplasty.

Age Factors↗
PubMed1997

Use of evidence-based medical therapy in patients undergoing percutaneous coronary revascularization in the United States, Europe, and Canada. Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) and Canadian Coronary Atherectomy Trial (CCAT) investigators.

The objective of this study was to examine whether there are international variations in the use of evidence-based medical therapy in patients undergoing percutaneous coronary revascularization. We analyzed the medical therapy of patients in the United States (US) (n = 878), Europe (n = 134), and Canada (n = 274) who underwent percutaneous coronary revascularization in either the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) (enrollment from August 1991 to April 1992) or the Canadian Coronary Atherectomy Trial (CCAT) (enrollment from July 1991 to August 1992). We found that at the time of hospital admission, Canadian patients had the highest rates of treatment with aspirin (95% vs 57% US and 78% Europe; p = 0.002), calcium antagonists (75% vs 48% US and 43% Europe; p 0.0001), beta blockers (60% vs 32% US and 46% Europe; p = 0.02), and combination anti-ischemic therapy (67% vs 43% US and 56% Europe; p = 0.0001). By discharge, however, Canadian patients had the lowest rates of treatment with nitrates (12% vs 40% US and 44% Europe; p = 0.0001) and combination anti-ischemic therapy (29% vs 53% US and 47% Europe; p < 0.01). At both admission and discharge, rates of treatment with angiotensin-converting enzyme inhibitors and lipid-lowering agents were < 15% in all 3 regions. We conclude that significant international variations exist in the use of evidence-based medical therapy in patients undergoing percutaneous coronary revascularization.

Adrenergic beta-Antagonists↗
PubMed1997

Economic implications of the prophylactic use of intraaortic balloon counterpulsation in the setting of acute myocardial infarction. The Randomized IABP Study Group. Intraaortic Balloon Pump.

Intraaortic balloon counterpulsation (IABP) has been shown to improve coronary artery patency and reduce the rates of recurrent myocardial ischemia and its sequelae in selected patients when used within 24 hours of acute myocardial infarction. The economic implications of prophylactic IABP use are unknown. We obtained hospital bills for 102 patients enrolled in the Randomized IABP Trial (56%) and converted charges to costs using each hospital's Medicare cost report. In-hospital costs for patients who had 48 hours of IABP were compared with those of patients who did not. The costs of angiographic and clinical complications were determined. Small differences in clinical and angiographic characteristics existed between patients in the economic substudy and the overall population, but overall angiographic and clinical outcomes were comparable. Costs for patients who had IABP versus control patients were similar: mean $22,357 +/- $14,369 versus $19,211 +/- $8,414, median (25th and 75th percentiles) $17,903 ($15,787, $22,147) versus $17,913 ($15,144, $21,433), p = 0.45. Hospital costs were higher with the development of recurrent ischemia: mean $23,125 +/- $7,690 versus $20,416 +/- $12,449, median $21,069 ($17,896, $26,885) versus $17,492 ($14,892, $20,998) p = 0.02. Patients who had an adverse clinical event (death, stroke, reinfarction, and emergency revascularization) also had higher hospital costs: mean $25,598 +/- $10,024 versus $19,790 +/- $12,045, median $21,877 ($18,380, $28,049) versus $17,364 ($14,773, $20,779), p = 0.002. The prophylactic use of IABP in patients at high risk of infarct artery reocclusion within 24 hours of acute myocardial infarction provides sustained clinical benefit without substantially increasing hospital costs.

Aged↗
PubMed1997

Racial variation in the use of coronary-revascularization procedures. Are the differences real? Do they matter?

BACKGROUND: Studies have reported that blacks undergo fewer coronary-revascularization procedures than whites, but it is not clear whether the clinical characteristics of the patients account for these differences or whether they indicate underuse of the procedures in blacks or overuse in whites. METHODS: In a study at Duke University of 12,402 patients (10.3 percent of whom were black) with coronary disease, we calculated unadjusted and adjusted rates of angioplasty and bypass surgery in blacks and whites after cardiac catheterization. We also examined patterns of treatment after stratifying the patients according to the severity of disease, angina status, and estimated survival benefit due to revascularization. Finally, we compared five-year survival rates in blacks and whites. RESULTS: After adjustment for the severity of disease and other characteristics, blacks were 13 percent less likely than whites to undergo angioplasty and 32 percent less likely to undergo bypass surgery. The adjusted black:white odds ratios for receiving these procedures were 0.87 (95 percent confidence interval, 0.73 to 1.03) and 0.68 (95 percent confidence interval, 0.56 to 0.82), respectively. The racial differences in rates of bypass surgery persisted among those with severe anginal symptoms (31 percent of blacks underwent surgery, vs. 45 percent of whites, P<0.001) and among those predicted to have the greatest survival benefit from revascularization (42 percent vs. 61 percent, P<0.001). Finally, unadjusted and adjusted rates of survival for five years were significantly lower in blacks than in whites. CONCLUSIONS: Blacks with coronary disease were significantly less likely than whites to undergo coronary revascularization, particularly bypass surgery - a difference that could not be explained by the clinical features of their disease. The differences in treatment were most pronounced among those predicted to benefit the most from revascularization. Since these differences also correlated with a lower survival rate in blacks, we conclude that coronary revascularization appears to be underused in blacks.

Angioplasty, Balloon, Coronary↗
PubMed1997

Medical care costs and quality of life after randomization to coronary angioplasty or coronary bypass surgery. Bypass Angioplasty Revascularization Investigation (BARI) Investigators.

BACKGROUND: Randomized trials comparing coronary angioplasty with bypass surgery in patients with multivessel coronary disease have shown no significant differences in overall rates of death and myocardial infarction. We compared quality of life, employment, and medical care costs during five years of follow-up among patients treated with angioplasty or bypass surgery. METHODS: A total of 934 of the 1829 patients enrolled in the randomized Bypass Angioplasty Revascularization Investigation participated in this study. Detailed data on quality of life were collected annually, and economic data were collected quarterly. RESULTS: During the first three years of follow-up, functional-status scores on the Duke Activity Status Index, which measures the ability to perform common activities of daily living, improved more in patients assigned to surgery than in those assigned to angioplasty (P<0.05). Other measures of quality of life improved equally in both groups throughout the follow-up period. Patients in the angioplasty group returned to work five weeks sooner than did patients in the surgery group (P<0.001). The initial mean cost of angioplasty was 65 percent that of surgery ($21,113 vs. $32,347, P<0.001), but after five years the total medical cost of angioplasty was 95 percent that of surgery ($56,225 vs. $58,889), a difference of $2,664 (P = 0.047). The five-year cost of angioplasty was significantly lower than that of surgery among patients with two-vessel disease ($52,930 vs. $58,498, P<0.05), but not among patients with three-vessel disease ($60,918 vs. $59,430). After five years of follow-up, surgery had an overall cost-effectiveness ratio of $26,117 per year of life added, but unacceptable ratios of $100,000 or more per year of life added could not be excluded (P=0.13). Surgery appeared particularly cost effective in treating diabetic patients because of their significantly improved survival. CONCLUSIONS: In patients with multivessel coronary disease, coronary-artery bypass surgery is associated with a better quality of life for three years than coronary angioplasty, after the initial morbidity caused by the procedure. Coronary angioplasty has a lower five-year cost than bypass surgery only in patients with two-vessel coronary disease.

Angioplasty, Balloon, Coronary↗
PubMed1997

Surrogate assessment of coronary artery disease patients' functional capacity.

An investigation of the surrogate assessment of coronary artery disease (CAD) patients' functional capacity was conducted using 193 patient and surrogate rater dyads. Mean age of patients and surrogate raters were 60.4 and 54.4 years, respectively. Patients and surrogates independently completed a brief questionnaire that assessed health and psychosocial factors. The Duke Activity Status Index (DASI) was contained in the patients' questionnaire, while a similar form modified to assess patients' functional capacity was imbedded in the surrogates' questionnaire. Results indicated similar psychometric characteristics and clinical validity for patients' self-report and surrogates' ratings, suggesting that the Surrogate Rating Form of the Duke Activity Status Index (DASI-SRF) is a reliable and valid proxy method of assessing patient's functional capacity when this information may not be obtained directly from the patient. Further, while there were no effects of surrogates' health and psychological characteristics on their ratings of patients' functional capacity, in comparison with other surrogates, spouses were more likely to rate patients higher in functional capacity. Exploration of the patient/care provider relationship via concurrent use of the DASI and DASI-SRF is discussed.

Adult↗
PubMed1997

Impact of early discharge after coronary artery bypass graft surgery on rates of hospital readmission and death. The Ischemic Heart Disease (IHD) Patient Outcomes Research Team (PORT) Investigators.

OBJECTIVES: This study examined the impact of early hospital discharge on short-term clinical outcomes of elderly patients treated with coronary artery bypass graft surgery (CABG) in the United States in 1992. BACKGROUND: Protocols that encourage earlier discharge of patients who have had CABG have been implemented across the country. Although delivery of efficient care benefits both patients and providers, premature discharge can adversely affect clinical outcomes, resulting in increased hospital readmissions and higher long-term costs. METHODS: We examined the prevalence of early discharge (postoperative length of stay < or = 5 days) among 83,347 non-health maintenance organization (HMO) Medicare patients who underwent CABG in the United States in 1992. Using logistic regression models, we identified patient characteristics associated with early discharge and obtained risk-adjusted rates of death and readmission or death for postoperative lengths of stay between 4 and 14 days. RESULTS: In 1992, 6% of Medicare patients undergoing CABG were discharged within 5 days of the operation. The prevalence of early discharge varied considerably among states, ranging from 1% to 21%. Patients discharged early tended to be younger and male and have fewer comorbid illnesses. Risk-adjusted rates of death and death or cardiovascular readmission were lowest among patients discharged early. CONCLUSIONS: As of 1992, early discharge of elderly patients treated with CABG in non-HMO settings was not associated with higher 60-day rates of death or readmission. This suggests that physicians were able to identify low risk candidates for early discharge. Variation across the nation in early discharge rates, along with the percentage of patients without major risk factors for adverse outcomes, suggests that higher rates of early discharge might be safely achieved.

Aged↗
PubMed1997

Geographic variation in resource use for coronary artery bypass surgery. IHD Port Investigators.

OBJECTIVES: The purpose of this study was to examine the national variability in patient-level cost and length of stay for coronary artery bypass grafting (CABG) in Medicare patients. METHODS: Retrospective multivariate regression analysis was done using Medicare administrative files and American Hospital Association files. Patients in the study had an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure code for CABG, with accompanying 1990 procedure data, in the Medicare Provider Analysis and Review File (n = 92,449). RESULTS: Outcome measures used were inpatient cost (exclusive of professional fees) and inpatient length of stay associated with bypass admission. The national average cost of bypass surgery was $22,847 (median $18,783), with an accompanying average length of stay of 16 days (median 13 days). Multivariate regression analysis revealed that patient-level cost and length of stay were related to clinical, demographic, hospital, and regional characteristics (R2 = 25% and 16%, respectively). After accounting for these characteristics at the patient level, considerable variation among states persisted in both cost and length of stay. In addition, states with similar adjusted lengths of stay varied widely with respect to adjusted cost. No relation was found at the state level between level of resource use and either procedural mortality or 60-day mortality/readmission rates. CONCLUSIONS: Considerable variability exists among states in patient-level cost and length of stay for CABG surgery, after adjusting to the extent possible for clinical, demographic, hospital, and regional characteristics. The lack of association at the state level between resource use and rates of mortality and hospital readmission suggests that costs could be reduced in many areas of the United States without compromising quality of care.

Aged↗
PubMed1997

Assessing the value of newer pharmacologic agents in non-ST elevation patients: a decision support system application.

Newer pharmacologic agents have demonstrated significant clinical and economic benefit in high-risk percutaneous transluminal coronary angioplasty (PTCA) patients. However, the higher costs of these agents may prohibit their use in lower-risk coronary artery disease (CAD) populations. We developed a decision support system (DSS) to determine the level of clinical effectiveness these newer agents must exhibit to be either cost-neutral or cost-effective in non-ST elevation patients. Our DSS evaluated six month cumulative costs, increased years of life saved (YOLS), and lifetime cost-effectiveness. We found that these therapies can cost as much as $1500 and be cost-neutral at six months if they reduce the composite endpoint of death, myocardial infarction (MI), or revascularization by 15%, and they may cost as much as $3000 and be cost-effective if they reduce this endpoint by 10%.

Abciximab↗
PubMed1996

Outcome of acute myocardial infarction according to the specialty of the admitting physician.

BACKGROUND: In order to limit costs, health care organizations in the United States are shifting medical care from specialists to primary care physicians. Although primary care physicians provide less resource-intensive care, there is little information concerning the effects of this strategy on outcomes. METHODS: We examined mortality according to the specialty of the admitting physician among 8241 Medicare patients who were hospitalized for acute myocardial infarction in four states during a seven-month period in 1992. Proportional-hazards regression models were used to examine survival up to one year after the myocardial infarction. To determine the generalizability of our findings, we also examined insurance claims and survival data for all 220,535 patients for whom there were Medicare claims for hospital care for acute myocardial infarction in 1992. RESULTS: After adjustment for characteristics of the patients and hospitals, patients who were admitted to the hospital by a cardiologist were 12 percent less likely to die within one year than those admitted by a primary care physician (P<0.001). Cardiologists also had the highest rate of use of cardiac procedures and medications, including medications (such as thrombolytic agents and beta-blockers) that are associated with improved survival. CONCLUSIONS: Health care strategies that shift the care of elderly patients with myocardial infarction from cardiologists to primary care physicians lower rates of use of resources (and potentially lower costs), but they may also cause decreased survival. Additional information is needed to elucidate how primary care physicians and specialists should interact in the care of severely ill patients.

Aged↗
PubMed1996

Depression and long-term mortality risk in patients with coronary artery disease.

Previous research has established that patients with coronary artery disease (CAD) have an increased risk of death if they are depressed at the time of hospitalization. Follow-up periods have been short in these studies; therefore, the present investigation examined this phenomenon over an extended period of time. Patients with established CAD (n = 1,250) were assessed for depression with the Zung Self-Rating Depression Scale (SDS) and followed for subsequent mortality. Follow-up ranged up to 19.4 years. SDS scores were associated with increased risk of subsequent cardiac death (p = 0.002) and total mortality (p < 0.001) after controlling for initial disease severity and treatment. Patients with moderate to severe depression had a 69% greater odds of cardiac death and a 78% greater odds of mortality from all causes than nondepressed patients. Increased risk was not confined to the initial months after hospitalization. Patients with high SDS scores at baseline still had a higher risk of cardiac death > 5 years later (p < 0.005). Compared with the nondepressed, patients with moderate to severe depression had an 84% greater risk 5 to 10 years later and a 72% greater risk after > 10 years. Patients with mild depression had intermediate levels of risk in all models. The heightened long-term risk of depressed patients suggests that depression may be persistent or frequently recurrent in CAD patients and is associated with CAD progression, triggering of acute events, or both.

Coronary Disease↗