Randomized trials of warfarin for atrial fibrillation.
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Atrial Fibrillation↗
Biomedical subjects
D E Singer
Publications and source records attributed to D E Singer.
Screening for diabetic retinopathy.
PURPOSE: To determine the appropriate patients, methods, and timing for screening for diabetic retinopathy. DATA SOURCES: Relevant articles were identified through prominent review articles, the authors' files, recommendations from experts, and a MEDLINE search (1986 to the present); additional references were selected from the bibliographies of identified articles. STUDY SELECTION: Selection of articles on the natural history of retinopathy was limited to large clinical series and formal epidemiologic studies of defined populations. Selection of articles on the therapeutic effect of photocoagulation and of glycemic control was limited to randomized trials. Sources bearing on the accuracy of screening modalities were necessarily more varied. DATA EXTRACTION: For important variables, individual estimates from multiple studies are presented rather than a single meta-analytic summary estimate. RESULTS: Screening for retinopathy is justifiable if early detection leads to less vision loss at an acceptable cost. The evidence shows that 1) laser therapy reduces the rate of vision loss by 50% among patients with proliferative retinopathy and macular edema, conditions that are often asymptomatic; 2) duration of diabetes is the main risk factor for retinopathy; and 3) standard ophthalmoscopic examination has only moderate sensitivity (about 80% in research settings) and specificity (greater than 90% for proliferative retinopathy but lower for macular edema), making seven-field stereophotography a more accurate method. Estimates of cost effectiveness indicate that screening for retinopathy not only saves years of vision but may be cost saving from a societal perspective. CONCLUSIONS: Screening for retinopathy in patients with diabetes, and subsequent photocoagulation therapy for those who have high risk macular edema or proliferative retinopathy, is clearly beneficial.
Cost-Benefit Analysis↗
The effect of aspirin on the risk of stroke in patients with nonrheumatic atrial fibrillation: The BAATAF Study.
Recent randomized trials have consistently demonstrated the marked efficacy of warfarin in reducing the risk of stroke caused by nonrheumatic atrial fibrillation. These trials have provided conflicting evidence on the effect of aspirin. We report the aspirin analysis from the BAATAF study, a trial in which control patients could choose to take aspirin. There we two strokes in 446 person-years with warfarin (annual rate of 0.45%); eight strokes in 206 person-years with aspirin, most at 325 mg per day (annual rate of 3.9%); and five strokes in 271 person-years among patients taking neither aspirin nor warfarin (annual rate of 1.8%). Simultaneously controlling for the other significant determinants of stroke in the BAATAF study (age, mitral annular calcification, and clinical heart disease), the relative rates (95% confidence interval) of stroke were: (1) warfarin/aspirin = 0.135 (0.029 to 0.64); (2) aspirin/(no aspirin and no warfarin) = 1.95 (0.64 to 5.97); and (3) warfarin/(no aspirin and no warfarin) = 0.263 (0.051 to 1.36). Our "treatment received" analysis argues that warfarin is strikingly more effective than aspirin in preventing stroke in nonrheumatic atrial fibrillation.
Aged↗
Association of HbA1c with prevalent cardiovascular disease in the original cohort of the Framingham Heart Study.
We studied the cross-sectional relationship between HbA1c and cardiovascular disease (CVD) in the survivors of the original cohort of the Framingham Heart Study (n = 1045). HbA1c was significantly related to prevalent CVD among women but not men. HbA1c was also related to hypertension and to the ratio of total to high-density lipoprotein cholesterol levels. In regression analyses that controlled for these and other potential risk factors, HbA1c remained significantly related to CVD among women. The relative odds of CVD increased 1.39-fold (95% confidence interval 1.06-1.83) for increases in HbA1c of 1% (e.g., for HbA1c from 5 to 6%). The relationship was not weakened when known diabetic subjects or subjects taking beta-blocker or thiazide medications were excluded from analysis. In contrast, there was no significant relationship between "casual" blood glucose and prevalent CVD. Our results reveal a strong, significant, independent association between hyperglycemia, measured by HbA1c, and CVD among older women.
Aged↗
Risk factors for stroke in patients with nonrheumatic atrial fibrillation: a case-control study.
PURPOSE: Randomized controlled trials have demonstrated that anticoagulant therapy is very effective at preventing stroke among patients with nonrheumatic atrial fibrillation. However, these trials have reported too few strokes for powerful risk factor analysis. Observational studies may provide additional information. The purpose of this study was to identify risk factors in a larger number of patients with stroke and nonrheumatic atrial fibrillation, using case-control methodology. PATIENTS AND METHODS: We identified all patients discharged from one hospital over an 8-year period who met our case definition of nonrheumatic atrial fibrillation and ischemic stroke (n = 134), and compared them with contemporaneous control subjects who were discharged with nonrheumatic atrial fibrillation without stroke (n = 131). RESULTS: Cases and controls were similar in terms of duration of atrial fibrillation; proportion with paroxysmal atrial fibrillation; percentage with a past medical history of angina, myocardial infarction, congestive heart failure, diabetes, or smoking; and mean left atrial size. In contrast, cases were significantly older than controls (78.5 versus 74.8 years, p = 0.002) and more likely to have a history of hypertension (55% versus 38%, p = 0.0093). The relative odds for stroke was 1.91 for patients with hypertension, 1.73 for patients older than 75 years, and 3.26 for patients with both factors. CONCLUSIONS: Our analysis suggests that age and hypertension should be considered when deciding upon long-term anticoagulant therapy to prevent stroke in patients with nonrheumatic atrial fibrillation.
Age Factors↗
Quantifying the potential benefit of CA 125 screening for ovarian cancer.
We develop a stochastic model of screening for ovarian cancer with serum levels of the CA 125 radioimmunoassay, a tumor-specific marker. The natural history of the disease is constructed using a four stage model characterized by a multivariate distribution for duration in each stage. Preserving its important features, we simplify the model to a function of two parameters; the average duration in stage I and the coefficient of variation of duration in each stage. A yearly screening program is superimposed using exponential CA 125 growth curves which result in stage-specific sensitivities corresponding to values reported in the literature. By implementing a computer simulation of the stochastic model, we estimate the benefit due to screening. This benefit is expressed as expected years of life saved per case of ovarian cancer. The model incorporates the stochastic nature of the disease process, allows easy analysis of repeated screens, and automatically accounts for correlation between subsequent tests. It provides the basis for planning optimal screening strategies with CA 125 testing.
Aged↗
Cocaine-related symptoms in patients presenting to an urban emergency department.
STUDY OBJECTIVES: Cocaine abuse is a serious social problem that precipitates a significant number of emergency hospital encounters. To determine the nature of cocaine-related symptoms, we studied patients with cocaine use presenting to all adult services of an urban emergency department. DESIGN: Review of consecutive cases, with analysis of clinical features. SETTING: All adult EDs of an urban teaching hospital. TYPE OF PARTICIPANTS: Patients acknowledging recent use of cocaine (within 72 hours) and/or with cocaine detected on a toxicologic screen. MEASUREMENTS AND MAIN RESULTS: Psychiatric complaints accounted for 44 (30.6%) presentations, followed by neurologic (17.4%), cardiopulmonary (16%), trauma (11.8%), and addiction-related (11.1%) symptoms. Cardiopulmonary symptoms were more frequently associated with intranasal than with IV or smoked cocaine (P = .003). Suicidal intent was the most common psychiatric reason for presentation, occurring in 24 patients (16.6%). Seventeen presented with trauma, including three involved in motor vehicle accidents. CONCLUSION: Cardiopulmonary symptoms such as chest pain and palpitations may be significantly more frequent in patients who use intranasal cocaine; suicidal intent is common among patients presenting with psychiatric symptoms related to cocaine; and the range of cocaine-related symptoms is varied, including not only psychiatric and cardiopulmonary symptoms but also trauma.
Adolescent↗
The impact of long-term warfarin therapy on quality of life. Evidence from a randomized trial. Boston Area Anticoagulation Trial for Atrial Fibrillation Investigators.
To determine the effect of long-term warfarin sodium therapy on quality of life, we surveyed 333 patients participating in a randomized, controlled trial of warfarin for the prevention of stroke in nonrheumatic atrial fibrillation. No significant differences between warfarin-treated and control patients were found on well-validated measures of functional status, well-being, and health perceptions. For example, the summary score for health perceptions was 68.8 in the warfarin-treated vs 66.6 in the control group (scale of 0 to 100; 95% confidence intervals for the difference, -1.6 to 6.0). In contrast, patients taking warfarin who had a bleeding episode had a significant decrease in health perceptions (-11.9; 95% confidence interval, -4.1 to -19.6). Warfarin therapy is not usually associated with a significant decrease in perceived health, unless a bleeding episode has occurred. Negative effects of warfarin treatment on health perceptions may be balanced by confidence in its protective effects.
Aged↗
Hospitalization decision in febrile intravenous drug users.
PURPOSE: To determine the frequency and to identify predictive factors of occult major illness in febrile intravenous drug users (IVDUs) presenting to an emergency room. PATIENTS AND METHODS: A prospective follow-up study was performed involving a consecutive series of 296 presentations of febrile IVDUs to a public hospital emergency room. Follow-up information was obtained for 283 presentations (95.6%). Physician's initial assessment was obtained for 204 presentations (70%). Illness was classified as major or minor using explicit criteria. Frequency of occult major illness was determined among patients without obvious major illness on presentation. Risk factors for occult major illness were determined. RESULTS: Occult major illness occurred in 11 patients (4%). This represented 11% of the 103 presentations without obvious major illness on presentation. Pneumonia and cellulitis occurred in 128 of 180 patients (71%) with obvious major illness on presentation. Bacteremia was present in seven of 11 patients with occult major illness. Physician predictions were not sufficiently sensitive to provide the basis of the hospitalization decision in febrile IVDUs. The best combination of features suggesting major illness were last use of intravenous drugs less than 5 days and fever greater than 38.8 degrees C (102.0 degrees F) (sensitivity 64%, specificity 77%). CONCLUSION: Clinical tests and physician assessments are unable to distinguish occult major illness from minor illness among febrile IVDUs at presentation. Occult major illness is best identified by blood culture. If patient follow-up is unreliable, then hospitalization of febrile IVDUs, while awaiting blood culture results, remains a wise policy.
Adult↗
Hospitalization decision in patients with community-acquired pneumonia: a prospective cohort study.
PURPOSE: To identify a low-risk subset of patients with community-acquired pneumonia that could safely be treated in the ambulatory setting; and to assess how clinicians make the hospitalization decision. PATIENTS AND METHODS: We performed a prospective, observational study of 280 ambulatory and hospitalized adults with clinical and radiographic evidence of pneumonia. Patients were followed to assess all potential morbid complications and 6-week mortality. Physicians responsible for managing these patients were surveyed to assess the reasons for treating in a hospital or ambulatory setting and the therapies that dictate hospitalization. RESULTS: Sixty-one percent (170 of 280) of patients did not have an indication for admission at presentation using modified Appropriateness Evaluation Protocol criteria (a severe vital sign abnormality, alteration in mental status, suppurative complication, arterial hypoxemia, severe laboratory abnormality, or an acute coexistent medical problem requiring admission independent of the pneumonia). Among these 170 patients, 38% had a complicated course defined as death within 6 weeks, development of a new suppurative or medical complication due to pneumonia, intensive care unit admission, persistent fever or use of intravenous fluids or oxygen beyond 3 days, hospitalization lasting more than 3 days, or subsequent hospitalization in patients initially treated in the ambulatory setting. Five predisposing factors for a complicated course were identified in logistic regression models. The odds ratio for age more than 65 years was 2.7; for comorbid illness, 3.2; for temperature more than 38.3 degrees C (101 degrees F), 4.1; for immunosuppression, 12.0; and for a high-risk etiology, 23.3. The risk of a complicated course increased linearly with the number of risk factors, from 12% with none to 100% with four or more factors (p less than 0.001). Physicians most often relied on the general clinical appearance of the patient when making the triage decision, and most commonly cited intravenous antibiotics and chest physical therapy as treatments requiring hospitalization. CONCLUSIONS: If validated, our findings could improve physicians' assessment of prognosis, and may identify a low-risk subset of patients with community-acquired pneumonia who could safely be managed in the ambulatory setting.
Adult↗
Prognosis of patients hospitalized with community-acquired pneumonia.
PURPOSE: Our purpose was to determine which clinical features predict short-term mortality in patients with community-acquired pneumonia. PATIENTS AND METHODS: We conducted a prospective multicenter study of 347 patients hospitalized in Pittsburgh (the derivation cohort) and 253 hospitalized and ambulatory patients in Boston (the validation cohort) with clinical and radiographic evidence of pneumonia. Patients in the derivation cohort underwent an extensive microbiologic evaluation including bacteriologic sputum culture, blood cultures, direct fluorescent antibody testing for Legionella species, and serologic testing for Mycoplasma pneumoniae, Legionella species, and Chlamydia TWAR. RESULTS: The overall mortality was 18% in the derivation cohort and 13.2% in the validation cohort. We identified five independent predictors of mortality in the derivation cohort: pleuritic chest pain (risk ratio, 0.4; 95% confidence interval [CI], 0.17 to 0.99), mental status changes (risk ratio, 2.6; 95% CI, 1.4 to 4.6), a severe vital sign abnormality (risk ratio, 2.1; 95% CI 1.2 to 3.6), neoplastic disease (risk ratio, 5.0; 95% CI, 2.7 to 9.1), and "high-risk" pneumonia etiology (risk ratio, 2.8; 95% CI, 1.6 to 5.0). A mortality index based on these factors accurately classified patients into five risk classes of increasing mortality. In the derivation cohort, the 6-week mortality rates were 0% in class I, 2.9% in class II, 13.1% in class III, 32.7% in class IV, and 89.5% in class V. There was little deterioration in the predictive accuracy of the model when tested in the validation cohort: mortality was 2.2% in class I, 0% in class II, 13.5% in class III, 33.3% in class IV, and 55.6% in class V. CONCLUSIONS: This prognostic classification may help direct triage decisions, assess appropriateness of care, and guide the design and analysis of therapeutic trials in patients with community-acquired pneumonia.
Adolescent↗
Tests of glycemia in diabetes mellitus. Their use in establishing a diagnosis and in treatment.
PURPOSE: To assess the usefulness of urine glucose testing, physician-based and self blood glucose monitoring, and assays of glycated hemoglobin in diagnosing and treating diabetes mellitus. DATA IDENTIFICATION: Relevant literature in English from 1957 through early 1988 was identified via textbooks, original research articles, and review and policy papers, supplemented by a computer-based search of the National Library of Medicine MEDLINE database. STUDY SELECTION: Articles were selected because of prominence, based on frequent citation or policy authoritativeness, and relevance to the epidemiologic and clinical constructs of this paper. RESULTS: We analyze the epidemiologic studies underlying the higher diagnostic glycemic thresholds for diabetes proposed by the National Diabetes Data Group and we suggest a diagnostic strategy in which glycated hemoglobin may substitute for glucose tolerance testing. Our section on treatment stresses matching the intensiveness of hypoglycemic therapy with the intensiveness of monitoring: emphasizing the role of self blood glucose monitoring. Our findings and recommendations are summarized in the figures and tables. CONCLUSIONS: Major advances in the diagnosis and management of diabetes have been made in the past 10 years. In particular, an array of epidemiologic studies have provided a logical basis for diagnostic standards, and two new means of assessing glycemia--glycated hemoglobin and self-monitoring of blood glucose--have become widely available. These tests allow more convenient approaches to diagnosis, and provide a fuller description of glycemia, permitting more informed and intensive therapy.
Blood Glucose↗
Diabetic myocardial infarction. Interaction of diabetes with other preinfarction risk factors.
To assess the effect of diabetes on outcome after acute myocardial infarction (MI), we compared a cohort of 228 type II (non-insulin-dependent) diabetic patients who had sustained acute MI with a similar number of nondiabetic patients with MI. Thirty-day mortality was greater in the diabetic group (27 vs. 17%). However, diabetic patients were older and had more cardiovascular disease before MI. Analyses accounting for such baseline risk revealed a complex effect of diabetes. The relative risk (RR) of dying from MI due to diabetes was greatest among patients with lowest baseline risk (RR 7.3) and least among those at highest baseline risk (RR 0.83). These effects were most striking with transmural MI, which was highly lethal for those with diabetes. Analyses with pulmonary edema as the endpoint support the significant risk conferred by diabetes and its interaction with baseline risk. Diabetes is a risk factor for poor outcome after MI, particularly among patients whose pre-MI cardiovascular status otherwise appears normal.
Aged↗
Screening for diabetes mellitus.
Diabetes mellitus in nonpregnant adults is a chronic affliction that leads to significant vascular and neuropathic disease. Diabetes during pregnancy can lead to perinatal complications. Both of these types of diabetes are common, often asymptomatic, and readily diagnosable by glucose tolerance testing. As a result, screening can identify many previously undiagnosed patients. However there is only limited evidence that screening results in net therapeutic benefit. In the case of gestational diabetes, controlled trials indicate that hypoglycemic therapy decreases the frequency of macrosomia, but has no effect on perinatal mortality. Our analyses indicate that screening for gestational diabetes is a low-cost intervention that produces a small expected benefit. Screening for diabetes in the nonpregnant adult (almost always a type II diabetic) is not recommended, because the link between improving glucose control and reducing diabetic complications is currently too weak. Screening might be reasonable for particular patients, for example, obese persons who would be spurred to lose weight by a demonstration of glucose intolerance. Screening for type I diabetes followed by immunomodulating therapy is still too experimental for confident analysis.
Cost-Benefit Analysis↗
Hypothesis: altered idiotype induces immune suppression.
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Animals↗
The triage decision in pulmonary edema.
The authors studied the clinical courses of 216 prospectively selected patients with cardiogenic pulmonary edema presenting to an emergency ward (EW) to identify which patients should be triaged to the intensive care unit (ICU). The first four hours were considered the EW or pre-triage phase of hospitalization. During the EW phase, 108 patients remained stable; 33 of them developed cardiopulmonary complications over the next two days. Logistic regression identified four significant independent features that distinguished these 33 patients from the remaining patients: four-hour diuresis less than 1L, history of prior pulmonary edema, T-wave abnormalities, and jugular venous distention. A model containing the four variables predicted hospital complications with a sensitivity of 81% and a specificity of 65%. In comparison, the sensitivity of physicians in admitting to the ICU patients who would go on to have complications was 70%, with a specificity of 63%. In a model containing a term for the physicians' actual triage decision, all four independent predictors remained significant, producing an overall sensitivity of 81% and an overall specificity of 69%.
Aged↗
Smoking cessation following admission to a coronary care unit.
OBJECTIVE: To determine the impact of an episode of serious cardiovascular disease on smoking behavior and to identify factors associated with smoking cessation in this setting. DESIGN: Prospective observational study in which smokers admitted to a coronary care unit (CCU) were followed for one year after hospital discharge to determine subsequent smoking behavior. SETTING: Coronary care unit of a teaching hospital. PATIENTS: Preadmission smoking status was assessed in all 828 patients admitted to the CCU during one year. The 310 smokers surviving to hospital discharge were followed and their smoking behaviors assessed by self-report at six and 12 months. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Six months after discharge, 32% of survivors were not smoking; the rate of sustained cessation at one year was 25%. Smokers with a new diagnosis of coronary heart disease (CHD) made during hospitalization had the highest cessation rate (53% vs. 31%, p = 0.01). On multivariate analysis, smoking cessation was more likely if patients were discharged with a diagnosis of CHD, had no prior history of CHD, were lighter smokers (less than 1 pack/day), and had congestive heart failure during hospitalization. Among smokers admitted because of suspected myocardial infarction (MI), cessation was more likely if the diagnosis was CHD than if it was noncoronary (37% vs. 19%, p less than 0.05), but a diagnosis of MI led to no more smoking cessation than did coronary insufficiency. CONCLUSION: Hospitalization in a CCU is a stimulus to long-term smoking cessation, especially for lighter smokers and those with a new diagnosis of CHD. Admission to a CCU may represent a time when smoking habits are particularly susceptible to intervention. Smoking cessation in this setting should improve patient outcomes because cessation reduces cardiovascular mortality, even when quitting occurs after the onset of CHD.
Analysis of Variance↗