Physicians' survival predictions for patients with acute congestive heart failure.

BACKGROUND: Current guidelines suggest that patients with low likelihoods of survival may be excluded from intensive care. Patients with new or exacerbated congestive heart failure are frequently but not inevitably admitted to critical care units. OBJECTIVE: To assess how well physicians could predict the probability of survival for acutely ill patients with congestive heart failure, and in particular how well they could identify patients with small chances of survival. METHODS: This was a prospective cohort study done in the emergency departments of a university hospital, a Veterans Affairs medical center, and a community hospital. The study population was consecutive adults for whom new or exacerbated congestive heart failure, diagnosed clinically, was a major reason for the emergency department visit. Physicians caring for the study patients in the emergency departments recorded their judgments of the numeric probability that each patient would survive for 90 days and for 1 year. The patients vital status at 90 days and 1 year was ascertained by multiple means, including interview, chart review, and review of hospital and state databases. RESULTS: By calibration curve analysis, the physicians underestimated survival probability at both 90 days and 1 year, particularly for patients they judged to have the lowest probabilities of survival. Their predictions had modest discriminating ability (receiver operating characteristic curve areas, 0.66 [SE = 0.020] for 90 days; 0.63 [SE = 0.017] for 1 year). The physicians identified only 15 patients they judged to have a 90-day survival probability of 10% or less, whose survival rate was actually 33.3%. CONCLUSIONS: Physicians have great difficulty predicting survival for patients with acute congestive heart failure and cannot identify patients with poor chances of survival. Current triage guidelines that suggest patients with poor chances of survival may be excluded from critical care may be impractical or harmful.

Altered membrane anisotropy gradients of plasma membranes of living peripheral blood leukocytes in aging and Alzheimer's disease.

Several reports have suggested that membrane rigidity, a term that refers to the relative motion of membrane constituents, is decreased in Alzheimer's Disease. Accordingly, a series of fluorescent membrane probes was used to evaluate the rigidity from the surface to the center of the outer hemi-leaflet of the plasma membrane of living neutrophils, monocytes and lymphocytes. Anisotropy, a parameter which increases with increasing membrane rigidity, was calculated from flow cytometric measurements of vertically and horizontally polarized components of the fluorescence emission of the probes. These preliminary experiments suggest that whereas membrane rigidity in certain regions of the plasma membrane of peripheral blood leukocytes is increased as expected in elderly controls, it is decreased in Alzheimer's disease.

Iron deficiency anemia and iron therapy effects on infant developmental test performance.

The behavioral effects of iron deficiency and its treatment were evaluated in a double-blind randomized controlled community-based study of 191 Costa Rican infants, 12 to 23 months of age, with various degrees of iron deficiency. The Bayley Scales of Infant Development were administered before and both 1 week and 3 months after IM or oral administration of iron. Appropriate placebo-treated control infants were also tested. Infants with iron deficiency anemia showed significantly lower mental and motor test scores, even after considering factors relating to birth, nutrition, family background, parental IQ, and the home environment. After 1 week, neither IM nor oral iron treatments differed from placebo treatment in effects on scores. After 3 months, lower mental and motor test scores were no longer observed among iron-deficient anemic infants whose anemia and iron deficiency were both corrected (36%). However, significantly lower mental and motor test scores persisted among the majority of initially anemic infants (64%) who had more severe or chronic iron deficiency. Although no longer anemic, they still showed biochemical evidence of iron deficiency after 3 months of treatment. These persistent lower scores suggest either that iron therapy adequate for correcting anemia is insufficient to reverse behavioral and developmental disturbances in many infants or that certain ill effects are long-lasting, depending on the timing, severity, or chronicity of iron deficiency anemia in infancy.

Prediction of survival of critically ill patients by admission comorbidity.

The objective of this study was to determine how well the Charlson index of comorbidity would predict mortality of critically ill patients; and how the predictive ability of the index would compare with that of the comorbidity component (Chronic Health Points) of the APACHE II system. This prospective cohort study included in its setting an intensive care unit (ICU) and intermediate ICU (IICU) in a teaching hospital. Patients included a previously assembled inception cohort of 201 patients consecutively admitted to either unit, followed until death or discharge from the hospital, excluding patients admitted after coronary artery bypass grafting, for planned dialysis, or transferred to the IICU from another intensive care unit. Main outcome measures were recorded as death in hospital versus survival at discharge. For each patient we had prospectively obtained all data necessary to predict the probability of in-hospital death using the APACHE II system, and to classify comorbidity using the Charlson index. The Charlson index had significant ability to discriminate between patients who would live and who would die (ROC curve area = 0.67, SE = 0.05). The Chronic Health Points component of APACHE II had no significant discriminating ability (ROC area = 0.57, SE = 0.05), although the full APACHE II system was an excellent predictor (area = 0.87, SE = 0.04). Logistic regression analyses suggested that the Charlson index could contribute significant (p = 0.03) prognostic information to that obtained from the components of APACHE II other than Chronic Health, i.e., acute physiological derangement, age, and reason for admission, but the Chronic Health Points component of APACHE II could not so contribute to the rest of APACHE II (p = 0.19). Our conclusion is that use of the detailed information about comorbidity captured by the Charlson index could improve prognostic predictions even for critically ill patients.

The impact of age on utilization of intensive care resources.

The impact of age on admission practices and pattern of care were examined in 599 admissions to a medical intensive care unit (MICU) and 290 patients on the conventional medical care divisions of the same hospital. Four age groups were compared: under 55, 55 to 64, 65 to 74, and 75 years of age and over. Severity of illness and prior health were assessed using the Acute Physiology Score (APS) and the Chronic Health Evaluation (CHE) instruments. Resource utilization was assessed using the Therapeutic Intervention Scoring System (TISS) and hospital charges. Patients 65 years of age and over comprised 48% of the MICU sample. The distribution of CHE was different among the four groups. Twenty-one percent of patients under 55 years of age had no prior chronic illness, as compared to less than 8% of older patients. The APS at admission was similar for all age groups, as was admission, daily, and total TISS. Hospital survival declined with age from 85% to 70%, while the likelihood of being designated do not resuscitate (DNR) increased from 10% to 24%. Differences in hospital survival disappeared when controlling for severity of illness and prior health, but differences in DNR status did not. Still, elderly DNR patients received as much resources as younger DNR patients and this was more than non-DNR patients. The sample of patients treated on conventional medical divisions had age distribution similar to the MICU sample. There was some evidence that admission APS (median, 5, 5, 6, 6, respectively, P = .055) and maximum APS (median, 5, 5, 7, 8, respectively, P = .023) differed slightly across age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen therapy in the management of urinary incontinence in postmenopausal women: a meta-analysis. First report of the Hormones and Urogenital Therapy Committee.

OBJECTIVE: To apply a meta-analysis to available data to evaluate the efficacy of estrogen therapy in the management of postmenopausal women with urinary incontinence. METHODS: The literature review incorporated English language articles based on a search of EXCERPTA MEDICA, BIOSIS, and MEDLINE from January 1969 to June 1992. Criteria included: peer-reviewed original article, confirmed diagnosis of urinary incontinence, an estrogen-treated group, and outcome data on subjective improvement, quantitation of fluid loss, or maximum urethral closure pressure. In addition, the data had to allow comparison between treated and control groups in controlled trials or an estimated change in uncontrolled series. meta-analytic methods were applied only to studies considered to be controlled clinical trials. RESULTS: Of 166 articles reviewed, 143 did not meet the entry criteria; six were considered controlled clinical trials and 17 were uncontrolled series. Meta-analysis found an overall significant effect of estrogen therapy on subjective improvement for all subjects (P < .01) and for subjects with genuine stress incontinence alone (P < .05). The results showed no significant effect on quantity of fluid loss but a significant effect (P < .05) on maximum urethral closure pressure. However, the latter result was influenced by only one study showing a large effect. CONCLUSION: It appears from this analysis that estrogen subjectively improves urinary incontinence in postmenopausal women. However, the studies included nonhomogeneous groups, and the diagnostic criteria, therapeutic interventions, and outcome assessments varied considerably.

Bladder training in older women with urinary incontinence: relationship between outcome and changes in urodynamic observations.

The purpose of this study was to clarify the mechanism by which bladder training affects urinary incontinence. Urodynamic data and specific urodynamic diagnoses of 108 women with urinary incontinence were compared before and 6 months after treatment with bladder training. Before treatment, 76 women had sphincteric incompetence, 11 had detrusor instability, and 16 had both. After treatment, 33 women no longer fulfilled the urodynamic diagnostic criteria for either sphincter or detrusor dysfunction. Controlling for severity before treatment, the number of incontinent episodes post-treatment was not associated with change in urodynamic diagnosis. Only the first sensation to void, voided volume, compliance, functional urethral length, and flow time showed any significant changes between pre- and post-treatment evaluations; however, none were correlated with change in the number of incontinent episodes. Bladder training does not appear to affect lower tract urodynamic variables or specific urodynamic diagnosis, and it is likely that its mechanism of action reflects adaptive behavioral changes. Physiologic changes not detected with techniques and/or criteria used in this study may still occur.

Efficacy of estrogen supplementation in the treatment of urinary incontinence. The Continence Program for Women Research Group.

OBJECTIVE: To assess the efficacy of cyclic postmenopausal hormone replacement in treating urinary incontinence in hypoestrogenic women. METHODS: Eighty-three hypoestrogenic women complaining of urinary incontinence were included. All patients were community-dwelling, age 45 years or older, with involuntary loss of urine occurring at least once a week and urodynamic evidence of genuine stress incontinence and/or detrusor instability. Evaluation consisted of a comprehensive clinical and urodynamic research protocol. The hypoestrogenic entry criterion was a plasma estradiol level of 30 pg/mL or less. Parabasal cells on vaginal smears were also monitored. The primary outcome was the number of incontinent episodes per week, as documented on a standardized urinary diary. Secondary outcomes were the quantity of fluid loss, voluntary diurnal and nocturnal micturition frequency, generic and condition-specific health-related quality of life measurements, and patient satisfaction. A randomized, placebo-controlled, double-blind design was used. Subjects in the treatment group were given conjugated equine estrogens (0.625 mg) and medroxyprogesterone (10 mg) cyclically for 3 months. Controls received placebo tablets. RESULTS: (All results are presented as mean +/- standard deviation.) Subjects were 67 +/- 9 years old. The menopause duration was 18 +/- 11 years. The duration of incontinence was 9 +/- 9 years. Estradiol level at baseline was 9 +/- 9 pg/mL, and the parabasal cell count was 42 +/- 44%. The number of incontinent episodes at baseline was 13 +/- 10 for the treatment group and 16 +/- 4 for controls. No significant changes occurred in the number of incontinent episodes after treatment: 10 +/- 10 for the treatment group, and 13 +/- 14 for the controls (P = .7). Also, fluid loss was not changed: 176 +/- 106 g for the treatment group and 64 +/- 88 g for the control group at baseline, and 101 +/- 150 and 51 +/- 69 g after treatment, respectively (P = .7). There were no significant differences for either diurnal or nocturnal voluntary micturition, quality of life measures, or patient's perception of improvement. CONCLUSION: Three-month cyclic hormone replacement therapy did not affect either clinical or quality of life variables of incontinent, hypoestrogenic women. Long-term effects are unlikely to be substantially different. The use of estrogen supplementation as preventive or adjuvant therapy was not evaluated in this study.

Postoperative radiotherapy improves survival in squamous cell carcinoma of the hypopharynx.

BACKGROUND: Postoperative radiation is considered to be "standard of care" therapy for advanced, resectable squamous cell carcinoma of the head and neck. This approach has been supported by retrospective data but has not been validated in randomized clinical trials. PATIENTS AND METHODS: The present analysis examined the clinical course of 110 patients with squamous cell cancer of the hypopharynx treated with surgery alone (n = 65) and postoperative radiotherapy alone (n = 45) between 1966 and 1990. Staging of patients was performed using the 1988 American Joint Committee on Cancer criteria. Cox regression analyses identified clinical and pathologic factors that were significant for disease-free and overall survival. Crude and adjusted cancer-specific survival rates were calculated. RESULTS: The postoperative radiotherapy group presented with more advanced disease than the surgery alone group (stage III and IV combined, 96% versus 77%, P = 0.015). Crude 5-year cancer-specific survival probabilities were 43% for the postoperative therapy group and 27% for the surgery alone group (P = NS). Adjusted 5-year survival rates, correcting for differences in significant prognostic variables between groups, were 18% and 48%, respectively, for the surgery and postoperative radiotherapy groups (P = 0.029). CONCLUSIONS: The addition of postoperative radiotherapy was associated with improved disease-free and adjusted overall cancer-specific survival in patients with advanced hypopharyngeal squamous cancer. The potential survival benefit of postoperative radiotherapy should be addressed in a randomized clinical trial.

Determining a range of false-positive rates for which ROC curves differ.

Many indices have been proposed for summarizing the information contained in the ROC curve. When comparing two ROC curves, though, there are times when global summary measures are either not optimal or not appropriate. The author presents a method for directly comparing true-positive rates for two diagnostic, screening or prognostic tools, determining over what range of false-positive values the tests differ. The method is applicable for independent or dependent samples. An example concerning gallium citrate imaging is presented, as well as an example using a prognostic index for severity of illness in the ICU. The range of false-positive rates for which the ROC curves differ is determined for each example.

Analyzing a portion of the ROC curve.

The area under the ROC curve is a common index summarizing the information contained in the curve. When comparing two ROC curves, though, problems arise when interest does not lie in the entire range of false-positive rates (and hence the entire area). Numerical integration is suggested for evaluating the area under a portion of the ROC curve. Variance estimates are derived. The method is applicable for either continuous or rating scale binormal data, from independent or dependent samples. An example is presented which looks at rating scale data of computed tomographic scans of the head with and without concomitant use of clinical history. The areas under the two ROC curves over an a priori range of false-positive rates are examined, as well as the areas under the two curves at a specific point.

Comparing the areas under more than two independent ROC curves.

For a diagnostic test, the area under the associated receiver operating characteristic (ROC) curve is considered a measure of the efficacy of the test. Statistical methodology for the comparison of the areas under more than two independent ROC curves is developed. The jackknife is used to devise an F test using the pseudovalues as data. A Studentized range (SR) test is also considered using the original area estimates. A Monte Carlo study is performed to evaluate the significance level and power of the two test statistics. Both statistics conform well to the 0.10, 0.05, and 0.01 significance levels when the sampling design is balanced between cases with and without the disease. Power is also comparable. For unbalanced designs, the SR test on the original area estimates is very conservative while the F test on pseudovalues performs well. The F test is recommended as the method of choice for comparing the areas, although for balanced designs the SR test, with its computational simplicity, may be preferred.

Combining and comparing area estimates across studies or strata.

A method for combining and comparing medical tests across studies or strata is presented. The area under the receiver operating characteristic (ROC) curve is the parameter of interest to be used for comparison. The combined area is a weighted average of the areas under the curve in each study or stratum. A chi-square test for equality of areas across strata can be used to compare the areas. The power of the test is also explored. The methods presented are simple and require only knowledge of estimates of area and their standard errors. Either parametric or nonparametric estimates of the area can be used.

How well can physicians estimate mortality in a medical intensive care unit?

The accuracies of physicians' predictions of mortality for 523 patients in a medical intensive care unit were compared with estimates derived from a logistic model. The model utilized a popular severity-of-illness measure, the APACHE II. Accuracy was assessed through its components resolution (discrimination) and calibration. Physicians could better discriminate survivors from nonsurvivors, as measured by the area under the receiver operating characteristic curve (0.89 for physicians vs 0.83 for APACHE II model, p less than 0.001) and by resolution (0.103 for physicians vs 0.130 for APACHE II model, p less than 0.001). Overall, the APACHE II model was better calibrated (0.003 for APACHE II vs 0.021 for physicians, p less than 0.001). While the APACHE II model was better calibrated in the central probability ranges, physicians could more accurately identify those most likely to die. Decisions on withholding or withdrawing treatment are being made daily in intensive care units based on physicians' subjective prognostic estimates. At least for experienced physicians at a major medical center, these estimates are comparable in accuracy to quantitative models.

An international comparison of physicians' judgments of outcome rates of cardiac procedures and attitudes toward risk, uncertainty, justifiability, and regret.

OBJECTIVE: Compare U.K. and U.S. physicians' judgments of population probabilities of important outcomes of invasive cardiac procedures; and values held by them about risk, uncertainty, regret, and justifiability relevant to utilization of cardiac treatments. DESIGN: Cross-sectional study. SETTING: University hospital and VA medical center in the United States; two teaching hospitals in the United Kingdom. PARTICIPANTS: 171 housestaff and attendings at U.S. teaching hospitals; 51 physician trainees and consultants at U.K. hospitals. MEASURES: Judgments of probabilities of severe complications and deaths due to Swan-Ganz catheterization, cardiac catheterization, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG); judgments of malpractice risks for case vignettes; Nightingale's risk-aversion instrument; Gerrity's reaction-to-uncertainty instrument; questions about need to justify decisions; responses to case vignettes regarding regret. RESULTS: The U.S. physicians judged rates of two bad outcomes of cardiac procedures (complications due to cardiac catheterization; death due to CABG) to be significantly higher (p < or = 0.01) than did the U.K. physicians (U.S. medians, 5 and 3.5, respectively; U.K. medians 3 and 2). The median ratio of (risk of malpractice suit I error of omission)/(risk of suit I error of commission) judged by U.K. physicians, 3, was significantly (p=0.0006) higher than that judged by U.S. physicians, 1.5. The U.K. physicians were less often risk-seeking in the context of possible losses than the U.S. physicians (odds ratio for practicing in the U.K. as a predictor of risk seeking 0.3, p=0.003). The U.K. physicians had significantly more discomfort with uncertainty than did the U.S. physicians, as reflected by higher scores on the stress scale (U.K. median 48, U.S. 42, p=0.0001) and the reluctance-to-disclose-uncertainty scale (U.K. 40, U.S. 37, p < 0.0001) of the Gerrity instrument. There was no clear international difference in perceived need to justify decisions, or in regret. CONCLUSIONS: The results were not clearly consistent with the uncertainty hypothesis that international practice variation is due to differences in judged rates of outcomes of therapy or with the imperfect-agency hypothesis that practice variation is due to differences in physicians' personal values. The causes and implications of practice variations remain unclear.

Bacteremia in young urban women admitted with pyelonephritis.

The objective of this study was to determine the rate of bacteremia in young women admitted to the hospital with presumed pyelonephritis and compare it with other published rates. The study design was a retrospective, structured chart review and a review of published reports of bacteremic pyelonephritis. An urban county teaching hospital provided the setting for the study. The patients were nonpregnant women (n = 98) 44 years of age or younger who were without bladder dysfunction and who had not been admitted to an intensive care unit. Further criteria for participation included discharge with the diagnosis of acute pyelonephritis. Blood cultures were ordered for 69 women; the results of 64 were noted in the chart. Twenty-three women (35.9% of those cultured; 23.4% of all patients) were diagnosed with bacteremia. In patients for whom blood culture results were obtained, trends developed between those patients with bacteremia and those with complicated pyelonephritis, defined as a known or newly discovered genitourinary abnormality or a risk factor (P = 0.044), those who were black (P = .044), those with higher pulses on admission (P = .050), those with more white blood cells per high-powered field after urinalysis (P = 0.007), and those whose fever lasted longer (P = 0.033). Blood culture results were positive in two patients whose urine cultures were negative. This comparatively high bacteremia rate supports routine ordering of blood cultures for urban women suspected of having pyelonephritis.

Computer-assisted instruction in probabilistic reasoning during the inpatient medicine clerkship.

The acceptability and utility of computer-assisted instruction in probabilistic reasoning was assessed for medicine clerkship students. After a pretest, the experimental (n = 40), but not the control students (n = 39), completed a program that we designed. The program contained the test and its answers. After program exposure, experimental students rated their knowledge of the program's content significantly higher (p = 10(-4)) than control students. On the identical posttest, experimental students also scored significantly higher than control students (p = 10(-4)) and improved their scores significantly more (p = 10(-3)). They rated ease-of-use items significantly higher than content-relevance items (p = 10(-4)). We conclude that computer-assisted instruction in probabilistic reasoning is acceptable to clerkship students, and that it may improve their knowledge and skills in this area. However, students may rate the vehicle of this instruction more highly than its content.

Assessing Medicaid recipient access and satisfaction. Fee-for-service, case management, and capitation.

Medicaid increasingly requires enrollment in managed care programs. This study assessed access to care, satisfaction with care, and appointment wait times during the transition from fee for service to managed care using three annual Medicaid recipient surveys. There was little evidence of dissatisfaction or poorer access among managed care recipients. Fee-for-service recipients, compared to primary care case management, reported greater general (91 vs. 78%, p < .01) and specialty care access (92 vs. 80%, p < .01). When appointments were required, adult HMO enrollees, compared to case management, had longer waits for routine care in the second (5.8 +/- 8.2 days vs. 4.0 +/- 6.6) and third surveys (5.5 +/- 6.9 days vs. 3.8 +/- 7.3); waits for other appointments did not consistently differ by program. There were no significant program differences in overall satisfaction. Findings are tempered by the potential for response bias and geographic confounding. Continued monitoring is crucial to assure that access and satisfaction remain high in Medicaid managed care.

Effect of different types of Medicaid managed care on childhood immunization rates.

Medicaid managed care can improve access to prevention services, such as immunization, for low-income children. The authors studied immunization rates for 7,356 children on Medicaid in three managed care programs: primary care case management (PCCM; n = 4,605), a voluntary HMO program (n = 851), and a mandatory HMO program (n = 1,900). Immunization rates (3:3:1 series) in PCCM (78%) exceeded rates in the voluntary HMO program (71%), which in turn exceeded those in the mandatory HMO program (67%). Adjusting for race, urban residence, and gender, compared to children in PCCM, children in the voluntary HMO program were less likely to complete the 3:3:1 series (OR = 0.75, CI = 0.63, 0.90), and children in the mandatory HMO program were even less likely to complete the series (OR = 0.59, CI = 0.51, 0.68). Results differed by individual HMOs. Monitoring of outcomes for all types of managed care by Medicaid agencies is imperative to assure better disease prevention for low-income children.