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Biomedical subjects

Harry P Selker

Publications and source records attributed to Harry P Selker.

At least 19 recordsLinked to original sources

Can multivariable risk-benefit profiling be used to select treatment-favorable patients for thrombolysis in stroke in the 3- to 6-hour time window?

BACKGROUND AND PURPOSE: The Stroke-Thrombolytic Predictive Instrument (Stroke-TPI) uses multivariate equations to predict outcomes with and without thrombolysis. We sought to examine whether such a multivariate predictive instrument might be useful in selecting patients with a favorable risk-benefit treatment profile for therapy after 3 hours. METHODS: We explored outcomes in patients from 5 major randomized clinical trials testing intravenous recombinant tissue plasminogen activator (rt-PA) classified by the Stroke-TPI as "treatment-favorable" or "treatment-unfavorable." We used iterative bootstrap re-sampling to estimate how such a model would perform on independent test data. RESULTS: Among patients treated within the 3- to 6-hour window, 67% of patients were classified by Stroke-TPI predicted outcomes as "treatment-favorable" and 33% were classified as "treatment-unfavorable." Outcomes in the treatment-favorable group demonstrated benefit for thrombolysis (modified Rankin Scale score < or =1: 44.0% with rt-PA versus 34.2 with placebo, P=0.005), whereas harm was demonstrated in the treatment-unfavorable group (modified Rankin Scale score < or =1: 31.3% with rt-PA versus 38.3% with placebo; P=0.004). Bootstrap resampling with complete cross-validation showed that the absolute margin of benefit in the treatment-favorable group diminished on average by 36% between derivation and independent validation sets, but still represented a significant tripling of improvement in benefit compared with conventional inclusion criteria (5.2% [interquartile range, 1.7% to 8.6%] versus 1.8% [interquartile range, -0.5 to 4.1], P<0.0001). CONCLUSIONS: Such multivariable risk-benefit profiling may be useful in the selection of acute stroke patients for rt-PA therapy even more than 3 hours after symptom onset. Prospective testing is indicated.

Aged↗

The stroke-thrombolytic predictive instrument: a predictive instrument for intravenous thrombolysis in acute ischemic stroke.

BACKGROUND AND PURPOSE: Many patients with ischemic stroke eligible for recombinant tissue plasminogen activator (rt-PA) are not treated in part because of the risks and benefits perceived by treating physicians. Therefore, we aimed to develop a Stroke-Thrombolytic Predictive Instrument (TPI) to aid physicians considering thrombolysis for stroke. METHODS: Using data from 5 major randomized clinical trials (n=2184) testing rt-PA in the 0- to 6-hour window, we developed logistic regression equations using clinical variables as potential predictors of a good outcome (modified Rankin Scale score < or =1) and of a catastrophic outcome (modified Rankin Scale score > or =5), with and without rt-PA. The models were internally validated using bootstrap re-sampling. RESULTS: To predict good outcome, in addition to rt-PA treatment, 7 variables significantly affected prognosis and/or the treatment-effect of rt-PA: age, diabetes, stroke severity, sex, previous stroke, systolic blood pressure, and time from symptom onset. To predict catastrophic outcome, only age, stroke severity, and serum glucose were significant; rt-PA treatment was not. For patients treated within 3 hours, the median predicted probability of a good outcome with rt-PA was 42.9% (interquartile range [IQR]=18.6% to 64.7%) versus 25.3% (IQR=9.8% to 46.2%) without rt-PA; the median predicted absolute benefit was 12.5% (IQR=5.1% to 21.0%). The median probability for a catastrophic outcome, with or without, rt-PA was 15.2% (IQR=8.0% to 31.2%). The area under the receiver-operator characteristic curve was 0.788 for the model predicting good outcome and 0.775 for the model predicting bad outcome. CONCLUSIONS: The Stroke-TPI predicts good and bad functional outcomes with and without thrombolysis. Incorporated into a usable tool, it may assist in decision-making.

Aged↗

Differences in triage thresholds for patients presenting with possible acute coronary syndromes: more than meets the eye.

BACKGROUND: Many studies have shown differences in cardiac care by racial/ethnic groups without accounting for institutional factors at the location of care. OBJECTIVE: Exploratory analysis of the effect of hospital funding status (public vs private) on emergency department (ED) triage decision making for patients with symptoms suggestive of acute coronary syndromes (ACSs) and on the likelihood of ED discharge for patients with confirmed ACS. STUDY DESIGN AND SETTING: Secondary analysis of data from a randomized controlled trial of 10,659 ED patients with possible ACS in five urban academic public and five private hospitals. The main outcome measures were the sensitivity and specificity of hospital admission for the presence of ACS at public and private hospitals and the adjusted odds of a patient with ACS not being hospitalized at public versus private hospitals. RESULTS: Of 10,659 ED patients, 1,856 had confirmed ACS. For patients with suspected ACS, triage decisions at private hospitals were considerably more sensitive (99 vs 96%; p<.001) but less specific (30 vs 48%; p<.001) than at public hospitals. The difference between hospital types persisted after adjustment for multiple patient-level and hospital-level characteristics. CONCLUSION: Significant differences in triage for patients with suspected ACS exist between public and private hospital EDs, even after adjustment for multiple patient demographic, clinical, and institutional factors. Further studies are needed to clarify the causes of the differences.

Acute Disease↗

Lessons learned combining N-of-1 trials to assess fibromyalgia therapies.

OBJECTIVE: Applying population research to individual treatment requires understanding the connections between patient-specific characteristics, population-based studies, and treatment responses. Conducting practice-based research using individual-focused (N-of-1) trials may aid this process. We combined N-of-1 trials to compare fibromyalgia therapies and to assess the feasibility and outcomes of this approach for practice-based effectiveness research. METHODS: Community- and center-based rheumatologists enrolled patients with fibromyalgia syndrome in randomized, double-blind, multi-crossover, N-of-1 trials comparing amitriptyline and the combination amitriptyline and fluoxetine. Fibromyalgia Impact Questionnaire outcomes were used for the individuals' treatment and combined across patients for sample-based analyses. Outcomes were compared with results from more standard trial designs. RESULTS: Eight rheumatologists enrolled 58 patients in N-of-1 trials. Most physicians and patients had not previously participated in clinical trials. Using several analytic methods, the pooled results showed a better outcome score (mean difference: -6.1 +/- 2.0 to -8.0 +/- 3.7 points) in patients taking combination therapy. These population results are similar to published outcomes from a more traditional crossover trial. Neither practice type nor patient characteristics were significantly associated with the observed treatment-effect variation. Most participants, irrespective of selected treatment, felt their individual N-of-1 trials were helpful. CONCLUSION: Implementation of the combined N-of-1 methodology is feasible in rheumatology practices and results confirm greater fibromyalgia improvement with combination therapy. This research approach broadens participation, although our trials' specifics likely influenced enrollment eligibility. In addition to individual benefits, combining N-of-1 trial data provides population research benefits. This patient-focused approach should be further explored to bridge research and practice.

Adult↗

Emergency physicians' fear of malpractice in evaluating patients with possible acute cardiac ischemia.

STUDY OBJECTIVE: We evaluate the association between emergency physicians' fear of malpractice and the triage and evaluation patterns of patients with symptoms suggestive of acute coronary syndrome. METHODS: We surveyed 33 emergency physicians of 2 university hospitals during the preintervention phase of an implementation trial of the Agency for Health Care Policy and Research Unstable Angina guideline in 1,134 study patients. The survey included a 6-item instrument that addressed concerns about malpractice and a measure of general risk aversion. We used hierarchical logistic regression to model emergency department (ED) triage decisions and diagnostic testing as a function of fear of malpractice, with adjustment for patient characteristics, Agency for Health Care Policy and Research guideline risk group, study site, and clustering by emergency physician. RESULTS: Overall, emergency physicians in the upper tertile of malpractice fear were less likely to discharge low-risk patients compared with emergency physicians in the lower tertile (adjusted odds ratio [OR] 0.34; 95% confidence interval [CI] 0.12 to 0.99; P=.05). Patients treated by emergency physicians in this group were also more likely to be admitted to an ICU or telemetry bed (adjusted OR 1.7; 95% CI 1.2 to 2.4). In addition, emergency physicians in the upper tertile of malpractice fear were more likely to order chest radiography, as well as cardiac troponin. Malpractice fear accounted for a similar amount of variance after controlling for emergency physicians' risk aversion. CONCLUSION: Malpractice fear accounts for significant variability in ED decisionmaking and is associated with increased hospitalization of low-risk patients and increased use of diagnostic tests.

Adult↗

Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial.

CONTEXT: The scarcity of data addressing the health effects of popular diets is an important public health concern, especially since patients and physicians are interested in using popular diets as individualized eating strategies for disease prevention. OBJECTIVE: To assess adherence rates and the effectiveness of 4 popular diets (Atkins, Zone, Weight Watchers, and Ornish) for weight loss and cardiac risk factor reduction. DESIGN, SETTING, AND PARTICIPANTS: A single-center randomized trial at an academic medical center in Boston, Mass, of overweight or obese (body mass index: mean, 35; range, 27-42) adults aged 22 to 72 years with known hypertension, dyslipidemia, or fasting hyperglycemia. Participants were enrolled starting July 18, 2000, and randomized to 4 popular diet groups until January 24, 2002. INTERVENTION: A total of 160 participants were randomly assigned to either Atkins (carbohydrate restriction, n=40), Zone (macronutrient balance, n=40), Weight Watchers (calorie restriction, n=40), or Ornish (fat restriction, n=40) diet groups. After 2 months of maximum effort, participants selected their own levels of dietary adherence. MAIN OUTCOME MEASURES: One-year changes in baseline weight and cardiac risk factors, and self-selected dietary adherence rates per self-report. RESULTS: Assuming no change from baseline for participants who discontinued the study, mean (SD) weight loss at 1 year was 2.1 (4.8) kg for Atkins (21 [53%] of 40 participants completed, P = .009), 3.2 (6.0) kg for Zone (26 [65%] of 40 completed, P = .002), 3.0 (4.9) kg for Weight Watchers (26 [65%] of 40 completed, P < .001), and 3.3 (7.3) kg for Ornish (20 [50%] of 40 completed, P = .007). Greater effects were observed in study completers. Each diet significantly reduced the low-density lipoprotein/high-density lipoprotein (HDL) cholesterol ratio by approximately 10% (all P<.05), with no significant effects on blood pressure or glucose at 1 year. Amount of weight loss was associated with self-reported dietary adherence level (r = 0.60; P<.001) but not with diet type (r = 0.07; P = .40). For each diet, decreasing levels of total/HDL cholesterol, C-reactive protein, and insulin were significantly associated with weight loss (mean r = 0.36, 0.37, and 0.39, respectively) with no significant difference between diets (P = .48, P = .57, P = .31, respectively). CONCLUSIONS: Each popular diet modestly reduced body weight and several cardiac risk factors at 1 year. Overall dietary adherence rates were low, although increased adherence was associated with greater weight loss and cardiac risk factor reductions for each diet group.

Adult↗

Medical error prevention in ED triage for ACS: use of cardiac care decision support and quality improvement feedback.

Medical errors in the care of patients who present with acute coronary syndrome (ACS)include errors in emergency department (ED) triage, such as the decision to send home a patient who presents with ACS or to hospitalize a patient who does not have ACS to the cardiac care unit (CCU), and errors in treatment, such as the failure to promptly use reperfusion therapy for patients who present with ST-elevation acute myocardial infarction(AMI). ECG-based acute cardiac ischemia time-insensitive predictive instrument(ACI-TIPI) and thrombolytic predictive instruments (TPIs), with a linked TIPI information system (TIPI-IS), provide real-time, concurrent, and retrospective decision support tools and feedback for the prevention of medical errors in the care of patients who present with ACS. In real-time, ACI-TIPI probabilities printed on the ECG header for the ED physician, provide an additional piece of information for triage decision making, and the ACI-TIPI Risk Management form reduces liability risk by prompting consideration and documentation of key clinical factors in the diagnosis of ACI. Also in real-time, the TPI increases overall coronary reperfusion therapy use. Concurrent flagging by TIPI-IS uses electronically acquired ECG and hospital data to provide concurrent alerts about potential misdiagnosis or mis-triage of patients with ACS. Retrospectively TIPI-IS-based feedback reports allow performance improvement. These examples of information technology tools integrated into ECG equipment already used in hospitals to deliver patient care demonstrate the potential to adapt other existing equipment or other patient care activities to enhance patient safety and error reduction.

Acute Disease↗

Acute coronary syndromes in the emergency department: diagnostic characteristics, tests, and challenges.

Failure to diagnose patients who have acute coronary syndromes (ACSs)-either acute myocardial infarction (AMI) or unstable angina pectoris (UAP)-who present to the emergency department (ED) remains a serious public health issue. Better understanding of the pathophysiology of coronary artery disease has allowed the adoption of a unifying hypothesis for the cause of ACSs: the conversion of a stable atherosclerotic lesion to a plaque rupture with thrombosis. Thus, physicians have come to appreciate UAP and AMI as parts of a continuum of ACSs. This article reviews the state of the art regarding the diagnosis of ACSs in the emergency setting and suggests reasons why missed diagnosis continues to occur, albeit infrequently.

Acute Disease↗

Evaluating the nondrug costs of formulary coverage restrictions.

PURPOSE: Clinicians often are required to switch prescribed therapy for their patients in response to health plan initiatives for controlling drug expenditures. To explore the effect of these initiatives, we sought clinicians' feedback regarding their practices and processes for switching patients' medications to accommodate insurance coverage. DESIGN: Self-administered Intranet-based survey of clinicians at an urban, tertiary-care hospital. METHODOLOGY: Using survey responses, we calculate nondrug costs induced by formulary cost-saving measures. PRINCIPAL FINDINGS: A total of 91 responses were received from 569 providers who were sent a request to complete the questionnaire via electronic mail (18 percent response rate). It took an average of 11.1, 18.9, and 16.4 minutes for physicians, nurses, and nurse practitioners/physician assistants, respectively, to make the medication switch. The mean number of switches per month ranged from 10.6 to 36.9. More than half the time spent on these switches is not directly reimbursed. Specific switch-induced intervention costs differed for different drug types. The effect on clinician workload tended to be an inconvenience. While the majority of physicians and nurse practitioners/physician assistants did not feel this process damaged patient-provider relations, most nurses did. CONCLUSIONS: In response to formulary restrictions, other costs are induced and incurred by providers and patients. The extent of patient costs, including those from adverse drug reactions, needs further study. More research is needed to elucidate costs and burden shifts as all parties involved evaluate and modify plans to moderate prescription drug expenditures.

Cost Control↗

Sex-based differences in response to recombinant tissue plasminogen activator in acute ischemic stroke: a pooled analysis of randomized clinical trials.

BACKGROUND AND PURPOSE: Women experience worse outcomes after stroke compared with men. Prior work has suggested sex-based differences in coagulation and fibrinolysis markers in subjects with acute stroke. We explored whether sex might modify the effect of recombinant tissue plasminogen activator (rtPA) on outcomes in patients with acute ischemic stroke. METHODS: Using a combined database including subjects from the National Institute of Neurological Disorders and Stroke (NINDS), Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) A and B, and the Second European Cooperative Acute Stroke Study (ECASS II) trials, we examined 90-day outcomes in patients randomized to rtPA versus placebo by sex. We used logistic regression to control for potential confounders. RESULTS: Among 988 women treated between 0 and 6 hours from symptom onset, patients receiving rtPA were significantly more likely than those receiving placebo to have a modified Rankin Score < or =1 (40.5% versus 30.3%, P<0.0008). Among 1190 men, the trend toward benefit in the overall group did not reach statistical significance (38.5% versus 36.7%, P=0.52). An unadjusted analysis showed that women were significantly more likely to benefit from rtPA compared with men (P=0.04). Controlling for age, baseline National Institutes of Health Stroke Scale, diabetes, symptom onset to treatment time, prior stroke, systolic blood pressure, extent of hypoattenuation on baseline computed tomography scan and several significant interaction terms (including onset to treatment time-by-treatment and systolic blood pressure-by treatment) did not substantially change the strength of the interaction between gender and rtPA treatment (P=0.04). CONCLUSIONS: In this pooled analysis of rtPA in acute ischemic stroke, women benefited more than men, and the usual gender difference in outcome favoring men was not observed in the thrombolytic therapy group. For patients presenting at later time intervals, when the risks and benefits of rtPA are more finely balanced, sex may be an important variable to consider for patient selection.

Acute Disease↗

In acute ischemic stroke, are asymptomatic intracranial hemorrhages clinically innocuous?

BACKGROUND: In patients with acute ischemic stroke, intracranial hemorrhages are categorized as symptomatic or asymptomatic based on the presence or absence of a clinically detectable neurological deterioration. Asymptomatic intracranial hemorrhages are believed by many to be clinically innocuous. We examined whether the occurrence of an asymptomatic intracranial hemorrhage affects functional outcome in patients with acute ischemic stroke (AIS) treated or not treated with recombinant tissue plasminogen activator (rt-PA). METHODS: We combined data from the NINDS rt-PA Stroke Trial and the ATLANTIS Trials, excluding patients with symptomatic intracranial hemorrhage (n=1193). We used generalized estimating equations to test whether asymptomatic intracranial hemorrhage altered the likelihood of a normal or near-normal outcome at 90 days, as measured across 4 commonly used functional outcome scales, controlling for other variables that affect outcome. To look at additional outcomes, including the likelihood of disability and death, we used logistic regression equations. Additionally, we systematically reviewed previous studies that assessed the effect of intracranial hemorrhage in AIS. RESULTS: In the combined database, the rate of asymptomatic intracranial hemorrhage was higher in rt-PA treated than in nontreated patients (9.9% versus 4.2%, P<0.0001). Controlling for other prognostic factors, the odds of a normal or near-normal outcome was lower when a patient had an asymptomatic intracranial hemorrhage, but this effect did not reach statistical significance (OR=0.69, 95% CI: 0.43 to 1.12, P=0.13). Similarly, the odds of not being moderately to severely disabled (modified Rankin Score < or =2) was also lower for patients with asymptomatic intracranial hemorrhage (OR=0.60, 95% CI: 0.33 to 1.08, P=0.09). Despite using a larger sample than any previously published study, the power in our study to detect a 30% decrease in the odds of a good outcome was inadequate ( approximately 32%). CONCLUSIONS: We could not confirm or exclude a clinically significant effect for asymptomatic intracranial hemorrhages based either on our analysis or on any previously published trial. Analysis of substantially larger databases are needed to assess the import of this common clinical event.

Aged↗

The impact of electrocardiographic left ventricular hypertrophy and bundle branch block on the triage and outcome of ED patients with a suspected acute coronary syndrome: a multicenter study.

We studied the impact on triage and outcome of the presence of left ventricular hypertrophy (LVH) and left/right bundle branch block (LBBB/RBBB) on the initial ED electrocardiogram (ECG) for patients with symptoms suggestive of an acute coronary syndrome (ACS). Secondary analysis of data from a prospective clinical trial of patients with chest pain or other symptoms suggesting ACS in six U.S. hospitals comparing patient demographics, clinical variables, and outcomes was used. Of 5,324 study patients, 3% had ECG-LVH, 3% had LBBB, 3% had RBBB, and 43% had ischemic ST segment or T wave abnormalities. Compared with patients without ST segment or T wave abnormalities, patients with ECG-LVH or BBB were older and were more likely to have a chief complaint of shortness of breath or a history of cardiac or related diseases. Patients with ECG-LVH or BBB had more diagnoses of congestive heart failure (CHF) and ACS compared with patients without these ECG abnormalities and were just as likely to have ACS as their diagnosis compared with patients with ischemic ST segment or T wave abnormalities. Having ECG-LVH or BBB did not alter the true-positive rate for ACS but increased the false-positive rate by almost 50%. Patients with ECG-LVH had approximately 3.5 times the 30-day mortality rate as those without these ECG abnormalities. It appears that for patients with symptoms suggestive of ACS, the presence of ECG-LVH or BBB did not alter the ability of ED clinicians to identify patients with ACS but was associated with a 50% higher false-positive admission rate compared with similar patients without these ECG abnormalities. With a short-term mortality rate 3.5 times that for patients without ECG-LVH, selected patients with ECG-LVH and symptoms suggesting ACS might benefit from hospitalization for further evaluation.

Age Distribution↗

Clinical features, triage, and outcome of patients presenting to the ED with suspected acute coronary syndromes but without pain: a multicenter study.

We studied the impact on triage and outcome of patients presenting to the emergency department (ED) with symptoms suggestive of an acute coronary syndromes (ACS) but without a complaint of pain. Data from a prospective clinical trial of patients with symptoms suggesting an ACS in the EDs of 10 US hospitals comparing patient demographics, clinical variables, and outcomes was used to perform a secondary analysis. Of 10,783 subjects, a final diagnosis of an ACS was confirmed in 24% of which 35% had acute myocardial infarction (AMI) and 65% unstable angina pectoris (UAP). Pain was absent in 6.2% of patients with acute ischemia and in 9.8% of those with AMI. Compared to similar patients who presented with pain, patients with painless ischemia were older, were more commonly women, had more cardiac and related diseases. Among patients with AMI, fewer patients without pain were admitted to critical care units compared to similar patients with pain. Among patients with AMI, logistic regression predicting lack of pain identified age, heart failure and diabetes, with only age and heart failure among all with ACS. After controlling for clinical features, lack of pain during acute ischemia predicted increased hospital mortality. We concluded that age and heart failure are independently associated with painless ACS, in addition to diabetes among those with AMI. Lack of pain predicts increased hospital mortality in patients with ACI through mechanisms that remain to be elucidated. There is a need for greater awareness in the general public of the different manifestations of ACS to enhance the recognition of and prompt response to their symptoms.

Adult↗