Planning for a kidney transplant: is my doctor listening?
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Decision Support Techniques↗
Biomedical subjects
D A Brand
Publications and source records attributed to D A Brand.
The "shaken-baby syndrome".
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Cerebral Hemorrhage↗
Prediction of the need for intensive care in patients who come to emergency departments with acute chest pain.
BACKGROUND: Patients who come to the emergency department with chest pain are a heterogeneous group. Some have ischemic heart disease that may lead to serious complications, whereas others have minor disorders. We performed a study to identify clinical factors that predict which patients will have complications requiring intensive care. METHODS: We first studied 10,682 patients with acute chest pain at seven hospitals between 1984 and 1986 (derivation set) to identify potential clinical predictors of the development of major complications. We then validated these predictors in a separate set of 4676 patients at one hospital between 1990 and 1994 (validation set). RESULTS: In the derivation set of patients, we identified the following set of clinical features, which, if present in the emergency department, were associated with an increased risk of complications: ST-segment elevation or Q waves on the electrocardiogram thought to indicate acute myocardial infarction, other electrocardiographic changes indicating myocardial ischemia, low systolic blood pressure, pulmonary rales above the bases, or an exacerbation of known ischemic heart disease. On the basis of these criteria, the patients in the validation set were stratified into four groups, with the risk of major complications in the first 12 hours ranging from 0.15 to 8 percent. After 12 hours, the probability of a major complication could be updated on the basis of whether the patient had already had a complication of major severity, a complication of intermediate severity, or a myocardial infarction (independent relative risks, 18.9, 7.7 and 4.0, respectively, as compared with patients without prior complications or myocardial infarction). CONCLUSIONS: The risk of major complications in patients with acute chest pain can be estimated on the basis of the clinical presentation and new clinical observations made during the hospital course. These estimates of risk help in making rational decisions about the appropriate level of medical care for patients with acute chest pain.
Acute Disease↗
Cardiologists' practices compared with practice guidelines: use of beta-blockade after acute myocardial infarction.
OBJECTIVE: Our purpose was to measure cardiologists' level of adherence to guidelines for long-term use of beta-adrenergic blocker therapy after acute myocardial infarction. BACKGROUND: Beta-blocker therapy after acute myocardial infarction has been shown to reduce the incidence of reinfarction and associated mortality. To learn about cardiologists' use of this therapy after hospital discharge and their level of adherence to American College of Cardiology guidelines, we analyzed insurance claims from 17 network-model health plans located throughout the United States. METHODS: The study group included 150 cardiologists who had contracts with one of the health plans and their 280 patients who were plan members (excluding Medicare enrollees) and received inpatient treatment for acute myocardial infarction that did not include revascularization during 1992. These patients accounted for 307 separate hospital admissions. Insurance claims were used to measure beta-blocker usage and to identify possible contraindications. RESULTS: Forty-three percent of the cases (131 of 307) involved apparent deviations from the guidelines: 11% of cases (35 of 307) involved possible errors of commission (beta-blocker given in the presence of a contraindication) and 31% (96 of 307) errors of omission (beta-blocker not given in the absence of a contraindication). Of the 185 patients who were eligible for the therapy (no contraindications), only 48% (89 of 185) were treated. CONCLUSIONS: Cardiologists currently exhibit a low level of compliance with their specialty's guidelines for postinfarction beta-blockade. Slightly fewer than 50% of the study patients who were eligible for treatment actually received a beta-blocker after hospital discharge. This result, combined with the drug's known level of effectiveness in preventing recurrent myocardial infarction, suggests that increased use could avert approximately 1,900 deaths annually nationwide.
Adrenergic beta-Antagonists↗
Medical practice profiling: concepts and caveats.
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Health Services Research↗
Ruling out acute myocardial infarction. A prospective multicenter validation of a 12-hour strategy for patients at low risk.
BACKGROUND: Although previous investigations have suggested that 24 hours is required to exclude acute myocardial infarction in patients who are admitted to a coronary care unit for the evaluation of acute chest pain, we hypothesized that a 12-hour period might be adequate for patients with a low probability of infarction at the time of admission. METHODS: Using a Bayesian model, we developed a strategy to identify candidates for a shorter period of observation from an analysis of a derivation set of 976 patients with acute chest pain who were admitted to three teaching and four community hospitals. In the derivation set, patients whose clinical characteristics in the emergency room predicted a low (less than or equal to 7 percent) probability of myocardial infarction had only a 0.4 percent risk of infarction if they had neither abnormal levels of cardiac enzymes nor recurrent ischemic pain during the first 12 hours of hospitalization. In an independent testing set of 2684 patients from the seven hospitals, 957 admitted patients (36 percent) were classified as candidates for this 12-hour period of observation according to a previously published multivariate algorithm. Few of these patients were actually transferred from a monitored setting at 12 hours. RESULTS: Of the 771 candidates for a 12-hour period of observation who did not have enzyme abnormalities or recurrent pain during the first 12 hours, 4 (0.5 percent) were subsequently found to have acute myocardial infarction, and only 3 (0.4 percent) died after primary cardiac arrests, all of which occurred three to five days after admission. Rates of other major cardiovascular complications were low in the patients who might have been transferred from the coronary care unit after 12 hours with this strategy. In patients with a higher initial risk of infarction, the standard strategy of 24-hour observation identified all but 11 of 739 acute myocardial infarctions (1 percent). CONCLUSIONS: Emergency room clinical data can be used to identify a large subgroup of patients for whom a 12-hour period of observation is normally sufficient to exclude acute myocardial infarction. Patient-specific evaluation and treatment can then proceed without the restrictions imposed by "rule-out" protocols for myocardial infarction.
Adult↗
Impact of physician experience on triage of emergency room patients with acute chest pain at three teaching hospitals.
PURPOSE: To determine whether the experience of the physician (as measured by postgraduate training level or time during the academic year) who performs the initial evaluation affects the triage of patients with acute chest pain. PATIENTS AND METHODS: Prospective data on the presenting clinical features, initial triage, final diagnosis, and complications were collected for 7,857 patients who presented to the emergency rooms of three teaching hospitals, including 1,118 (14%) with acute myocardial infarction (AMI), 2,477 (32%) with acute ischemic heart disease (AIHD) (i.e., AMI or unstable angina), and 335 (4%) with major complications. The experience of the evaluating physicians, who were in their first three postgraduate years in 93% of cases, was measured in three ways: (1) postgraduate training level, (2) month during the academic year, and (3) number of patients with acute chest pain previously evaluated. Multivariate logistic regression analyses that adjusted for hospital site and 20 clinical variables estimated the odds ratios for admission to the coronary care unit (CCU) and hospital associated with each incremental increase in physician experience. RESULTS: With more experience (as measured by postgraduate training level or time during the academic year), the sensitivity of physicians for admitting patients with AMI, AIHD, or major complications to the hospital increased. For example, each incremental increase in postgraduate training level carried a 1.4 increase in the adjusted odds ratio for admission of a patient with AIHD to the hospital (p less than 0.05), corresponding to an increase in the probability of admission from 93% to 97%. However, increasing physician experience was also associated with an elevated false-positive rate in admitting patients without these diagnoses to the CCU and hospital. Thus, each incremental increase in postgraduate training level carried a 1.2 increase in the adjusted odds ratio for admission of a patient without AIHD to the CCU and hospital (p less than 0.005), corresponding to an increase in the probability of admission from 34% to 47%. By receiver operating characteristic curve (ROC) regression analyses, these changes in triage patterns were consistent with movement along a single ROC curve, rather than a shift to a new or better ROC curve. CONCLUSIONS: As the experience of the physician who performed the initial evaluation increased, there was a lower threshold for admitting all patients with and without AMI, AIHD, or major complications to the CCU and hospital without a detectable improvement in diagnostic accuracy.
Adult↗
Outcomes in patients with myocardial infarction who are initially admitted to stepdown units: data from the Multicenter Chest Pain Study.
PURPOSE: To assess whether the admission of patients with chest pain to a stepdown unit would jeopardize the outcome of those patients who ultimately "ruled in" for a myocardial infarction. PATIENTS AND METHODS: We compared the risk of an adverse outcome in initially uncomplicated, "rule-out myocardial infarction" patients who were admitted directly to a stepdown unit (n = 58) or to a coronary care unit (n = 409) at 6 hospitals and who then ultimately "ruled in" for a myocardial infarction. RESULTS: An adverse outcome (death, serious complication, or invasive intervention) occurred in 16 (28%) stepdown unit patients compared with 159 (39%) coronary care unit patients. Among patients eligible for initial care in either location, the risk of an adverse outcome after controlling for clinical characteristics was similar in the two groups using each of two different multivariate approaches. CONCLUSION: Although our study was not of sufficient size to exclude the possibility of a small benefit from initial triage to a coronary care unit, our data suggest that (1) admission of initially uncomplicated chest pain patients with a relatively low probability of acute myocardial infarction to a stepdown unit does not seriously jeopardize those who eventually "rule in" for myocardial infarction; and (2) larger observational or randomized studies, which could reduce the residual possibility of somewhat higher risk in the stepdown unit, would be ethical to perform.
Aged↗
Comparison of the natural history of new onset and exacerbated chronic ischemic heart disease. The Chest Pain Study Group.
To compare the natural history of patients with new onset ischemic heart disease with that of patients with exacerbations of chronic ischemic heart disease, short- and long-term outcomes of 3,465 emergency room patients with acute ischemic heart disease at four community and three university hospitals were evaluated. Acute myocardial infarction was diagnosed in 598 (33%) of the 1,835 patients with a prior history of infarction or angina and 934 (57%) of the 1,630 without such a history (p less than 0.001). Patients with new onset ischemic heart disease with acute myocardial infarction were more likely than patients with infarction and exacerbated chronic ischemic heart disease to have Q wave infarction (57% versus 36%) and to receive thrombolytic therapy (11% versus 5%); they also had higher maximal creatine kinase levels (1,088 +/- 1,299 versus 733 +/- 906 U/liter) (p less than 0.0001 for all three). After adjustment for differences in clinical presentation and initial triage, patients with new onset ischemic heart disease with acute myocardial infarction were less likely than the comparison group to have congestive complications (odds ratio 0.63, 95% confidence interval 0.47 to 0.84, p less than 0.01) but not less likely to have arrhythmic, ischemic or overall complications. Among patients with angina without acute myocardial infarction, patients with new onset ischemic heart disease were less likely to have recurrent ischemic pain and congestive heart failure. In multivariate analysis of long-term follow-up data on 457 patients from one hospital, patients with new onset ischemic heart disease had better cardiovascular survival rates.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute Disease↗
A patient registry for orthopedic surgery.
Identification of patient subpopulations for retrospective clinical studies, documentation of residents' clinical experience, and other administrative purposes can be difficult and time consuming. The problem of identification is exacerbated when a teaching program involves several hospitals or when the desired subpopulation is not adequately defined by standard diagnosis or procedure codes used by the institution. A useful patient registry system is reported here for the storage and retrieval of data on orthopedic patients treated by surgical residents at a major teaching hospital and its affiliates. The registry uses a simple, yet powerful encoding scheme to describe patient entries. In addition to a multidimensional encoded description based on SNOMED, the system supports the entry of free text to provide greater detail. This combination gives the patient registry both power and versatility.
Hospital Information Systems↗
Clinical characteristics and outcome of acute myocardial infarction in patients with initially normal or nonspecific electrocardiograms (a report from the Multicenter Chest Pain Study).
To determine the prevalence and characteristics of acute myocardial infarction (AMI) patients who present to emergency departments with normal or nonspecific electrocardiograms (ECGs), data were analyzed from 7,115 consecutive patients in the Multicenter Chest Pain Study. AMI patients with normal or nonspecific initial ECGs (n = 107) were less likely to have a past history of coronary artery disease or to be diaphoretic on presentation (p less than 0.01) than AMI patients with initial ECGs highly suggestive of AMI (n = 811). The overall probability of AMI among patients with chest pain and initially normal or nonspecific ECGs was 3%, but ranged from less than 1 to 17% depending on the patient's age and sex and whether the patient had pressure-type pain or pain radiating to the shoulder, neck or arms. Among initially admitted patients, the time elapsed between onset of pain and presentation was similar in both groups. However, the time between onset of pain and definitive diagnosis of AMI by enzymes or clinical course was longer in patients with initially normal or nonspecific electrocardiograms (8.3 vs 7.5 hours, p less than 0.05), their peak creatine kinase levels were lower (mean 643 vs 1,032 mg/dl, p less than 0.001) and their mortality was slightly lower (6 vs 12%, p = 0.10). These findings suggest that AMI patients with initially normal or nonspecific ECGs may have a less severe short-term clinical outcome.
Adult↗
Candidates for thrombolysis among emergency room patients with acute chest pain. Potential true- and false-positive rates.
STUDY OBJECTIVE: To assess the potential clinical impact of thrombolytic therapy for acute myocardial infarction by determining true-positive and false-positive rates of criteria for eligibility among emergency room patients with acute chest pain. DESIGN: Prospective multicenter cohort study. SETTING: Emergency rooms of three university and four community hospitals. PATIENTS: Emergency room patients (7734) with acute chest pain. MEASUREMENTS AND MAIN RESULTS: Only 261 (23%) of 1118 patients with acute myocardial infarctions were 75 years of age or younger, presented within 4 hours of the onset of pain, and had emergency room electrocardiograms showing probable acute myocardial infarction: 60 (0.9%) of the 6616 patients without infarction also met these criteria (positive predictive value, 261/321 = 81%; CI, 77% to 86%). The positive predictive value could increase to about 88% (CI, 82% to 93%) if eligibility were based on the official hospital electrocardiogram reading. CONCLUSIONS: Because experience from published studies suggests that about one third of patients who meet these three eligibility criteria have other contraindications to thrombolysis, we estimate that about 15% of patients with acute myocardial infarction would meet the criteria for eligibility for thrombolysis that have been used in clinical trials at the time of emergency room presentation. Further, for every eight patients with true-positive results who are treated, one to two patients with false-positive results may also be treated if decisions are based on the interpretation of a single electrocardiogram.
Adult↗
Comparison of clinical presentation of acute myocardial infarction in patients older than 65 years of age to younger patients: the Multicenter Chest Pain Study experience.
To assess whether the manifestations of acute ischemic heart disease in the elderly are less typical than in younger patients, the presenting clinical features and their associated relative risks for acute myocardial infarction (AMI) were compared in 2,625 patients greater than or equal to 65 years of age and 5,109 patients less than 65 years of age. These patients were evaluated for acute chest pain in the emergency departments of 7 hospitals. The same features were associated with increased relative risks for AMI in younger and elderly patients. The relative risks among older patients, however, were consistently closer to 1.0 for classic features, including male gender, pressure-like quality of pain, substernal location, typical pattern of pain radiation and electrocardiographic evidence of ischemia or AMI. Analyses for the endpoint "acute ischemic heart disease" (i.e., AMI or unstable angina) yielded similar findings. Elderly patients were more likely to be admitted to the hospital (56 vs 35%; p less than 0.0001) and to the coronary care unit (37 vs 23%; p less than 0.0001) in the absence of either AMI or unstable angina. These data support the hypothesis that diagnosis of acute chest pain is especially difficult in elderly patients.
Adult↗
Relation of peak creatine kinase levels during acute myocardial infarction to presence or absence of previous manifestations of myocardial ischemia (angina pectoris or healed myocardial infarction).
The hypothesis that acute myocardial infarction (MI) is more extensive in patients without previous angina or healed MI was evaluated in 177 patients with documented recent acute MI. Ninety-nine patients (56%) had no previous angina or healed MI (negative history group), and the remaining 78 patients (44%) had a previous history of angina or healed MI (positive history group). The mean peak creatine kinase (CK) level in the negative history group was 784 compared with 419 IU in the positive history group (p less than 0.0001). The mean peak CK-MB level in the negative history group was 128 compared with 76 IU in the positive history group (p less than 0.001). The mean peak CK-MB level was higher in the negative history group after controlling for age, streptokinase administration, previous coronary artery bypass grafting or treatment with beta-blocking agents. Despite the high frequency of healed MI in the positive history group (73%), the rates of in-hospital complications were similar for the 2 groups. Patients with acute MI without previous angina or healed MI have substantially higher peak CK and CK-MB levels; this implies a larger MI than in patients with previous angina or healed MI.
Aged↗
A computer protocol to predict myocardial infarction in emergency department patients with chest pain.
To achieve more appropriate triage to the coronary care unit of patients presenting with acute chest pain, we used clinical data on 1379 patients at two hospitals to construct a simple computer protocol to predict the presence of myocardial infarction. When we tested this protocol prospectively in 4770 patients at two university hospitals and four community hospitals, the computer-derived protocol had a significantly higher specificity (74 vs. 71 percent) in predicting the absence of infarction than physicians deciding whether to admit patients to the coronary care unit, and it had a similar sensitivity in detecting the presence of infarction (88.0 vs. 87.8 percent). Decisions based solely on the computer protocol would have reduced the admission of patients without infarction to the coronary care unit by 11.5 percent without adversely affecting the admission of patients in whom emergent complications developed that required intensive care. Although this protocol should not be used to override careful clinical judgment in individual cases, the computer protocol for the most part yields accurate estimates of the probability of myocardial infarction. Decisions about admission to the coronary care unit based on the protocol would have been as effective as those actually made by the unaided physicians who cared for the patients, and less costly. Whether physicians who are aided by the protocol perform better than unaided physicians cannot be determined without further study.
Angina Pectoris↗
Diagnostic implications for myocardial ischemia of the circadian variation of the onset of chest pain.
To determine whether the occurrence of chest pain is randomly distributed during the day and to study whether the time of onset is useful in discriminating among causes of chest pain, patients older than 30 years who presented to 7 emergency departments with a chief complaint of chest pain unexplained by trauma or chest x-ray abnormalities were studied. A total of 7,759 patients presented during the study period; of these, 3,990 presented within 6 hours of the onset of pain and were included in the primary analysis. Chest pain caused by acute myocardial infarction, unstable angina pectoris and stable angina pectoris was more likely to begin during the period from 6 AM to noon than would be expected if the onset were uniformly distributed during the day (relative risks 1.15, 1.29 and 1.32, respectively), but chest pain that was caused by nonischemic cardiac causes and by noncardiac causes was also more likely to begin during the same time period (relative risks 1.28 and 1.17). Although chest pain from coronary arterial causes had a distinct circadian variation, the time of onset of pain was not a helpful criterion for determining the cause of chest pain.
Adult↗
Clinical characteristics and natural history of patients with acute myocardial infarction sent home from the emergency room.
In a prospective multicenter investigation of emergency room patients with acute chest pain, physicians admitted 96% of patients with acute myocardial infarction (AMI) and discharged 4%. Of 35 patients who were sent home with AMI, only 11 (31%) returned to the same hospital because of persistent symptoms. Compared with a control group of 105 randomly selected patients with AMI who were admitted from the emergency room, patients in whom AMI was missed were significantly younger, had less typical symptoms and were less likely to to have had prior AMI or angina or to have electrocardiographic evidence of ischemia or infarction not known to be old. Despite the less typical presentations of patients in whom AMI was missed, after controlling for age and sex, the short-term mortality rate was significantly higher among patients in whom AMI was missed but in whom it was detected through our follow-up procedures than in admitted AMI patients. As determined by independent reviewers, 49% of the missed AMIs could have been diagnosed through improved electrocardiographic reading skills or by admission of patients with recognized ischemic pain at rest or ischemic electrocardiographic changes not known to be old.
Age Factors↗
Sensitivity of routine clinical criteria for diagnosing myocardial infarction within 24 hours of hospitalization.
Myocardial infarction was diagnosed in 431 (30%) of 1460 patients with acute chest pain who had serial enzyme testing after admission to intensive or intermediate care units at three teaching and three community hospitals. The diagnosis was made within 12 hours of admission in 331 (77%) patients and within 24 hours in 415 (96%). Of the 16 patients with myocardial infarction who did not have enzyme abnormalities within 24 hours, 9 (56%) had recurrent ischemic pain during this 24-hour period. Of 451 patients who had neither enzyme abnormalities nor recurrent ischemic pain in the first 24 hours, only 7 (2%) ultimately met diagnostic criteria for myocardial infarction. These findings were prospectively validated in an independent testing set of 275 patients with myocardial infarction, 271 (99%) of whom either met diagnostic criteria for myocardial infarction or had recurrent ischemic pain within 24 hours of admission. These data suggest that 24 hours is nearly always a sufficient period to exclude myocardial infarction in patients without recurrent chest pain.
Aged↗