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Biomedical subjects

F Harrell

Publications and source records attributed to F Harrell.

8 recordsLinked to original sources
PubMed2000

Withholding versus withdrawing life-sustaining treatment: patient factors and documentation associated with dialysis decisions.

OBJECTIVE: We evaluated prospectively the use of acute hemodialysis among hospitalized patients to identify demographic and clinical predictors of and chart documentation concerning dialysis withheld and withdrawn. DESIGN: Prospective cohort study. SETTING: Five teaching hospitals. PATIENTS: Five hundred sixty-five seriously ill hospitalized patients who had not previously undergone dialysis who developed renal failure. MAIN OUTCOME MEASURES: Patient demographics, clinical characteristics, preferences, and prognostic estimates associated with having dialysis withheld rather than initiated and withdrawn rather than continued. Differences in chart documentation concerning decision-making for dialysis withheld, withdrawn, and continued. RESULTS: Older patient age, cancer diagnosis, and male gender were associated with dialysis withheld rather than withdrawn. Age and gender differences persisted after adjustment for patients' aggressiveness of care preference. Worse 2-month prognosis was associated with both withholding and withdrawing dialysis. Chart documentation of decision-making was lacking more often for patients with dialysis withheld than for dialysis withdrawn. CONCLUSIONS: Measuring the equity of life-sustaining treatment use will require evaluation of care withheld, not just care withdrawn. Older patients and men, after accounting for prognosis and function, are more likely to have dialysis withheld than withdrawn after a trial. Further exploration is needed into this disparity and the inadequate chart documentation for patients with dialysis withheld.

APACHE↗
PubMed1999

Older age, aggressiveness of care, and survival for seriously ill, hospitalized adults. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments.

BACKGROUND: Older age is associated with less aggressive treatment and higher short-term mortality due to serious illness. It is not known whether less aggressive care contributes to this survival disadvantage in elderly persons. OBJECTIVE: To determine the effect of age on short-term survival, independent of baseline patient characteristics and aggressiveness of care. DESIGN: Secondary analysis of data from a prospective cohort study. SETTING: Five academic medical centers participating in SUPPORT (Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments). PATIENTS: 9105 adults hospitalized with one of nine serious illnesses associated with an average 6-month mortality rate of 50%. MEASUREMENTS: Survival through 180 days of follow-up. In Cox proportional hazards modeling, adjustment was made for patient sex; ethnicity; income; baseline physical function; severity of illness; intensity of hospital resource use; presence of do-not-resuscitate orders on study day 1; and presence and timing of decisions to withhold transfer to the intensive care unit, major surgery, dialysis, blood transfusion, vasopressors, and tube feeding. RESULTS: The mean (+/- SD) patient age was 63 +/- 16 years, 44% of patients were female, and 16% were black. Overall survival to 6 months was 53%. In analyses that adjusted for sex, ethnicity, income, baseline functional status, severity of illness, and aggressiveness of care, each additional year of age increased the hazard of death by 1.0% (hazard ratio, 1.010 [95% CI, 1.007 to 1.013]) for patients 18 to 70 years of age and by 2.0% (hazard ratio, 1.020 [CI, 1.013 to 1.026]) for patients older than 70 years of age. Adjusted estimates of age-specific 6-month mortality rates were 44% for 55-year-old patients, 48% for 65-year-old patients, 53% for 75-year-old patients, and 60% for 85-year-old patients. Similar results were obtained in analyses that did not adjust for aggressiveness of care. Acute physiology and diagnosis had much larger relative contributions to prognosis than age. CONCLUSIONS: We found a modest independent association between patient age and short-term survival of serious illness. This age effect was not explained by the current practice of providing less aggressive care to elderly patients.

Activities of Daily Living↗
PubMed1997

Prognoses of seriously ill hospitalized patients on the days before death: implications for patient care and public policy.

Troubling aspects of the experiences of patients at the ends of their lives have fueled interest in special benefits or privileges for this group. There is a presumption that being "at the end of life" is discernible. This study examines this presumption using data from two previously collected databases: the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT) and the Acute Physiology and Chronic Health Evaluation III (APACHE III). Both studies generated multivariable estimates of survival prognosis for hospitalized patients. SUPPORT included 9,105 patients with one of nine serious illnesses in five hospitals over 4 yrs, of whom 2,360 died in the hospital and 4,537 died within 180 days of entry into the study. The APACHE III database describes 2,750 deaths in 16,622 ICU patients in 40 hospitals. The relationship of median estimates with time to death were examined for each source of data, for different diseases, and for ICU settings of care. In SUPPORT, the median predicted chance of survival for 2 months on the day before actual death was .17 (interquartile range, .02-.40) and was .51 (.31-.66) 1 wk before death. Median prognoses varied substantially among diseases: the median for congestive heart failure patients was a .62 chance of living 2 months on the day before death, while lung cancer had only a .17 chance and coma patients only an .11 chance. Median prognostication estimates were not much different when given by physicians and were only a little more pessimistic in APACHE (median estimate for hospital survival on the day before death was .14 and 7 days before was .45). To make plans about care and to optimally support most dying persons and families, conversations must occur while the patient still has a considerable chance of surviving the current episode of illness. Using statistical estimates of prognosis to designate a category of "terminally ill" patients for public policy purposes is unavoidably arbitrary, will often be contested, and will have differential effects upon those dying with differing diseases.

APACHE↗
PubMed1990

Characterization of Listeria monocytogenes isolates by Southern blot hybridization.

A synthetic deoxyribonucleotide probe for virulent Listeria monocytogenes, designated ADO7, was evaluated for its ability to identify restriction fragments of L. monocytogenes with nucleic acid sequences homologous with the beta-hemolysin gene by Southern blot hybridization of clinical and food isolates. The synthetic probe hybridized with three restriction fragments (approximately 1.1, 0.86, and 0.76 kb) of the serotype 1/2A isolates. Southern blot hybridization of the serogroup 4B isolates indicated that the nucleic acid sequences homologous with the beta-hemolysin gene probe were limited to a single restriction fragment of approximately 1 kb.

Animals↗
PubMed1982

Incremental value of the exercise test for diagnosing the presence or absence of coronary artery disease.

To determine the incremental value of the exercise test (ETT) for diagnosing coronary artery disease (CAD), we derived a multivariate logistic regression model for the pre-ETT prediction of CAD using data from 3840 patients at Duke University. We then applied the model to 324 patients at the Brigham and Women's Hospital. Using seven clinical factors, the multivariate model had an 84% overall predictive accuracy on both the training (Duke) and the validation (Brigham) sets of patients. Three ETT factors (ST-segment change in patients not taking digitalis, absence of ST-segment change in patients taking digitalis, ETT stopped because of ECG or blood pressure changes) had incremental, significant predictive power, but overall predictive accuracy based on both clinical and ETT factors improved only to 87%. When the ETT result was important enough to move the probability of CAD across a potential therapeutic threshold, the direction of the change in probability was correct only two-thirds of the time. Thus, the ETT was of limited value in predicting the presence or absence of CAD after other easily obtainable clinical data were taken into account.

Adult↗
PubMedDate not supplied

Predicting the outcomes of electrophysiologic studies of patients with unexplained syncope: preliminary validation of a derived model.

PURPOSE: To develop and validate a predictive model that would allow clinicians to determine whether an electrophysiologic (EP) study is likely to result in useful diagnostic information for a patient who has unexplained syncope. PATIENTS: One hundred seventy-nine consecutive patients with unexplained syncope who underwent EP studies at two university medical centers comprised the training sample. A test sample to validate the model was made up of 138 patients from the clinical literature who had undergone EP studies for syncope. DESIGN: Retrospective analysis of patients undergoing EP studies for syncope. The data collector was blinded to the study hypothesis; the electrophysiologist assessing outcomes was blinded to clinical and historical data. Clinical predictor variables available from the history, the physical examination, electrocardiography (ECG), and Holter monitoring were analyzed via two multivariable predictive modeling strategies (ordinal logistic regression and recursive partitioning) for their abilities to predict the results of EP studies, namely tachyarrhythmic and bradyarrhythmic outcomes. These categories were further divided into full arrhythmia and borderline arrhythmia groups. RESULTS: Important outcomes were 1) sustained monomorphic ventricular tachycardia (VT) and 2) bradyarrhythmias, including sinus node and atrioventricular (AV) conducting disease. The results of the logistic regression (in this study, the superior strategy) showed that the presence of organic heart disease [odds ratio (OR) = 3.0, p less than 0.001] and frequent premature ventricular contractions on ECG (OR = 6.7, p less than 0.004) were associated with VT, while the following abnormal ECG findings were associated with bradyarrhythmias: first-degree heart block (OR = 7.9, p less than 0.001), bundle-branch block (OR = 3.0, p less than 0.02), and sinus bradycardia (OR = 3.5, p less than 0.03). Eighty-seven percent of the 31 patients with important outcomes at EP study had at least one of these clinical risk factors, while 95% of the patients with none of these risk factors had normal or nondiagnostic EP studies. In the validation sample, the presence of one or more risk factors would have correctly identified 88% of the test VT patients and 65% of the test bradyarrhythmia patients as needing EP study. CONCLUSION: These five identified predictive factors, available from the history, the physical examination, and the initial ECG, could be useful to clinicians in selecting those patients with unexplained syncope who will have a serious arrhythmia identified by EP studies.

Arrhythmias, Cardiac↗