Does the Complications Screening Program flag cases with process of care problems? Using explicit criteria to judge processes

BACKGROUND

The Complications Screening Program (CSP) aims to identify 28 potentially preventable complications of hospital care using computerized discharge abstracts, including demographic information, diagnosis and procedure codes.

OBJECTIVE

To validate the CSP as a quality indicator by using explicit process of care criteria to determine whether hospital discharges flagged by the CSP experienced more process problems than unflagged discharges.

METHODS

The (CSP was applied to computerized hospital discharge abstracts from Mledicare beneficiaries > 65 years old admitted in 1994 to hospitals in California and Connecticut for major surgery or medical treatment. ()f 28 CSP complications, 17 occurred sufficient frequently to study. Discharges flagged (cases) and unflagged (controls) by the (CSP were sampled and photocopied medical records were obtained. Physicians specified detailed, objective, explicit criteria, itemizing 'key steps' in processes of care that could potentially have prevented or caused complications. Trained nurses abstracted medical records using these explicit criteria. Process problem rates between cases and controls were compared.

RESULTS

The final sample included 740 surgical and 416 medical discharges. Rates of process problems were high, ranging from 24.4 to 82.5% across CSP screens for surgical cases. Problems were lower for medical cases, ranging from 2.0 to 69.1% across CSP screens. Problem rates were 45.7% for surgical and 5.0% for medical controls. Rates of problems did not differ significantly across flagged and unflagged discharges.

CONCLUSIONS

The CSP did not flag discharges with significantly higher rates of explicit process problems than unflagged discharges. Various initiatives throughout the USA use techniques similar to the CSP to identify complications of care. Based on these CSP findings, such approaches should be evaluated cautiously.

Enzymatic syntheses of 6-(4H-selenolo[3,2-b]pyrrolyl)-L-alanine, 4-(6H-selenolo[2,3-b]pyrrolyl)-L-alanine, and 6-(4H-furo[3,2-b]pyrrolyl-L-alanine

6-(4H-Selenolo[3,2-b]pyrrolyl)-L-alanine 1, 4-(6H-selenolo[2,3-b]pyrrolyl)-L-alanine 2, and 6-(4H-furo[3,2-b]pyrrolyl)-L-alanine 3 have been synthesized via reactions of selenolo[3,2-b]pyrrole, selenolo[2,3-b]pyrrole, and furo[3,2-b]pyrrole, respectively, with L-serine. The reactions are catalyzed by Salmonella typhimurium tryptophan synthase.

Patient age and decisions to withhold life-sustaining treatments from seriously ill, hospitalized adults. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment

BACKGROUND

Patient age may influence decisions to withhold life-sustaining treatments, independent of patients' preferences for or ability to benefit from such treatments. Controversy exists about the appropriateness of using age as a criterion for making treatment decisions.

OBJECTIVE

To determine the effect of age on decisions to withhold life-sustaining therapies.

DESIGN

Prospective cohort study.

SETTING

Five medical centers participating in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT).

PATIENTS

9105 hospitalized adults who had one of nine illnesses associated with an average 6-month mortality rate of 50%.

MEASUREMENTS

Outcomes were the presence and timing of decisions to withhold ventilator support, surgery, and dialysis. Adjustment was made for sociodemographic characteristics, prognoses, baseline function, patients' preferences for life-extending care, and physicians' understanding of patients' preferences for life-extending care.

RESULTS

The median patient age was 63 years; 44% of patients were women, and 53% survived to 180 days. In adjusted analyses, older age was associated with higher rates of withholding each of the three life-sustaining treatments studied. For ventilator support, the rate of decisions to withhold therapy increased 15% with each decade of age (hazard ratio, 1.15 [95% CI, 1.12 to 1.19]); for surgery, the increase per decade was 19% (hazard ratio, 1.19 [CI, 1.12 to 1.27]); and for dialysis, the increase per decade was 12% (hazard ratio, 1.12 [CI, 1.06 to 1.19]). Physicians underestimated older patients' preferences for life-extending care; adjustment for this underestimation resulted in an attenuation of the association between age and decisions to withhold treatments.

CONCLUSION

Even after adjustment for differences in patients' prognoses and preferences, older age was associated with higher rates of decisions to withhold ventilator support, surgery, and dialysis.

Perceptions of quality of care and the decision to leave a practice

Little is known about how patients' perceptions of quality of care influence behavioral outcomes such as decisions to change the source of their care. We surveyed patients suspected of leaving a primary care internal medicine practice at an urban teaching hospital to examine their reasons for leaving, and to investigate whether decisions to leave were related to perceived quality of care. Of 185 respondents, 27 (15%) had left to follow their doctor to another practice. The other 98 (53%) patients who had left the practice cited reasons such as a change of insurance (51), physician care (31), practice operation (27), parking and transportation (24), physician departure (19), and geographic moves (17). Responses to global assessment items and a physician care rating scale were more closely associated with the decision to leave than were ratings of other specific aspects of care.

Risk for valvular heart disease among users of fenfluramine and dexfenfluramine who underwent echocardiography before use of medication

BACKGROUND

Because uncontrolled echocardiographic surveys suggested that up to 30% to 38% of users of fenfluramine and dexfenfluramine had valvular disease, these drugs were withdrawn from the market.

OBJECTIVE

To determine the risk for new or worsening valvular abnormalities among users of fenfluramine or dexfenfluramine who underwent echocardiography before they began to take these medications.

DESIGN

Cohort study.

SETTING

Academic primary care practices.

PATIENTS

46 patients who used fenfluramine or dexfenfluramine for 14 days or more and had echocardiograms obtained before therapy.

MEASUREMENTS

Follow-up echocardiography. The primary outcome was new or worsening valvulopathy, defined as progression of either aortic or mitral regurgitation by at least one degree of severity and disease that met U.S. Food and Drug Administration criteria (at least mild aortic regurgitation or moderate mitral regurgitation).

RESULTS

Two patients (4.3% [95% CI, 0.6% to 14.8%]) receiving fenfluramine-phentermine developed valvular heart disease. One had baseline bicuspid aortic valve and mild aortic regurgitation that progressed to moderate regurgitation. The second patient developed new moderate aortic insufficiency.

CONCLUSION

Users of diet medications are at risk for valvular heart disease. However, the incidence may be lower than that reported previously.

Physician Experience Caring for Dying Patients and Its Relationship to Patient Outcomes

BACKGROUND

The quality of end-of-life care has become important to care systems and the public. No research has assessed how physician factors affect patient and family experience.

OBJECTIVE

The objective of this study was to examine whether physicians' experience with dying is associated with differences in their patients' experiences while dying.

METHODS

This was a prospective cohort study. Data were obtained from five geographically diverse teaching hospitals. The survey population was composed of 765 attending physicians who had at least one patient enrolled in a study of those with a high risk of dying. The patients were 8203 hospitalized adults who were at least 80 years of age or had one of nine serious illnesses. The physician survey provided information about physician characteristics. Physician experience with death was stratified into five groups according to self-reported rate of dying patients in the physician's practice. Patient outcomes included pain, anxiety, depression, satisfaction with pain relief, presence and timing of do-not-resuscitate orders, concordance with their physicians about cardiopulmonary resuscitation, and hospital resource use.

RESULTS

Oncologists and pulmonologists or critical care physicians had more frequent contact with death. Physician characteristics other than specialty were not associated with death experience. Compared with the physician group having no experience with death, the adjusted odds ratios for accord on resuscitation preferences were 1.38 (95% confidence interval [CI], 0.96 to 1.98), 1.47 (95% CI, 1.03 to 2.11), 1.58 (95% CI, 1.10 to 2.26), and 1.64 (95% CI, 1.09 to 2.46) for the other four physician groups with progressively increasing experience. Other outcomes for patients were not associated with increasing physician experience.

CONCLUSION

Most physicians have little experience with dying, and physicians' experience with death has little effect on patient outcomes. The concentration of experience in a small segment of physicians offers opportunities for targeting improvements in the care of dying patients, including physician education.

Patterns of use, expenditures, and perceived efficacy of complementary and alternative therapies in HIV-infected patients

BACKGROUND

Complementary and alternative medicine (CAM) use is common in the general population, accounting for substantial expenditures. Among patients with human immunodeficiency virus (HIV) infection, few data are available on the prevalence, costs, and patterns of alternative therapy use.

METHODS

We carried out detailed telephone surveys and medical chart reviews for 289 active patients with HIV in a general medicine practice at a university-based teaching hospital in Boston, Mass. Data were collected on prevalence and patterns of CAM use, out-of-pocket expenditures, associated outcomes, and correlates of CAM use.

RESULTS

Of 180 patients who agreed to be interviewed, 122 (67.8%) used herbs, vitamins, or dietary supplements, 81 (45.0%) visited a CAM provider, and 43 (23.9%) reported using marijuana for medicinal purposes in the previous year. Patients who saw CAM providers made a median of 12 visits per year to these providers compared with 7 visits per year to their primary care physician and nurse practitioner. Mean yearly out-of-pocket expenditures for CAM users totaled $938 for all therapies. For the main reason CAM was used, respondents found therapies "extremely" or "quite a bit" helpful in 81 (81.0%) of 100 reports of supplement use, in 76 (65.5%) of 116 reports of CAM provider use, and in 27 (87%) of 31 reports of marijuana use. In multivariable models, college education (odds ratio [OR]=3.7, 95% confidence interval [CI]=1.9-7.1) and fatigue (OR=2.7, 95% CI=1.4-5.2) were associated with CAM provider use; memory loss (OR=2.3, 95% CI=1.1-4.8) and fatigue (OR=0.4, 95% CI=0.2-0.9) were associated with supplement use; and weight loss (OR=2.6, 95% CI=1.2-5.6) was associated with marijuana use.

CONCLUSIONS

Patients with HIV infection use CAM, including marijuana, at a high rate; make frequent visits to CAM providers; incur substantial expenditures; and report considerable improvement with these treatments. Clinical trials of frequently used CAMs are needed to inform physicians and patients about therapies that may have measurable benefit or measurable risk.

Infective dose modulates the balance between Th1- and Th2-regulated immune responses during blood-stage malaria infection

Plasmodium chabaudi infection of mice provides an excellent model for examining acquired immunity to the blood-borne stage of malaria infection. CD4+ T-cell receptor (TCR) alphabeta-bearing T lymphocytes play a critical role in mediating protection, ascribed to both T helper (Th) 1 and Th2 subsets. One factor that may influence the Th1/Th2 cell balance is infective dose. In this study, we found that the size of the infective dose of P. chabaudi, and thus the level of antigen presented to the immune system, correlated with the balance of responder CD4+ T-cell phenotypes. Increasing the infective dose in a resistant mouse strain enhanced the Th1 cytokine (interferon-gamma; IFN-gamma) response and reduced the Th2 cytokine (interleukin-4; IL-4) response. In contrast, increasing the infective dose in a susceptible mouse strain led to a prominent and accelerated up-regulation of IL-4 production. These data show that the dose of antigen can significantly affect the balance between Th1- and Th2-mediated immune functions during infection of the mammalian host with blood-stage malaria parasites. This demonstration that parasite numbers may modulate CD4+ T-cell regulation has novel implications for the successful implementation of antimalarial vaccination and chemotherapeutic strategies.

A comparison of generalist and pulmonologist care for patients hospitalized with severe chronic obstructive pulmonary disease: resource intensity, hospital costs, and survival. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment

PURPOSE

Both generalist and pulmonologist physicians care for patients with severe chronic obstructive pulmonary disease (COPD). We studied patients hospitalized with severe COPD to explore whether supervision of care by pulmonologists is associated with greater costs or better survival.

SUBJECTS AND METHODS

We studied 866 adults with severe COPD enrolled in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT), a prospective study at five academic medical centers. Patients were admitted to the hospital or transferred to an intensive care setting for treatment of severe COPD, defined by hypoxia (PaO2 <60 mm Hg) and hypercapnia (PaCO2 >50 mm Hg) or hypercapnia alone if on supplemental oxygen. Resource intensity was measured using a modified version of the Therapeutic Intervention Scoring System and estimated hospital costs. To account for differences in the patient case mix, propensity scores were developed to represent each patient's probability of having a pulmonologist as attending physician and each patient's probability of being in an intensive care unit (ICU) at study admission.

RESULTS

Of the 866 patients studied, 512 had generalists and 354 pulmonologists as their attending physicians. The median patient age was 70 years; 52% were male; 14% died within 30 days. After adjusting for baseline differences in patient characteristics, there were no differences in resource intensity and hospital costs in those treated by pulmonologists or generalists. Adjusted average resource intensity scores for the entire hospitalization were 16.5 for pulmonologists and 17.0 for generalists (P = 0.34). Estimated hospital costs were the same ($6,400) for patients treated by pulmonologists and generalists (P = 0.99). Patients with pulmonologists as attending physicians did not experience better survival. Comparing patients of pulmonologists to patients of generalists, the adjusted hazard ratio for 30-day mortality was 1.6 (95% confidence interval: 0.98, 2.5); the hazard ratio for 180-day mortality was 1.2 (0.9, 1.7).

CONCLUSIONS

Our findings suggest that for patients hospitalized with exacerbation of severe COPD, those with pulmonologist attending physicians do not have higher hospital resource use or better survival than those with generalist attending physicians.

Outcomes, preferences for resuscitation, and physician-patient communication among patients with metastatic colorectal cancer. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments

PURPOSE

To describe characteristics, outcomes, and decision making in patients with colorectal cancer metastatic to the liver, and to examine the relationship of doctor-patient communication with patient understanding of prognosis and physician understanding of patients' treatment preferences.

PATIENTS AND METHODS

The Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT) was a prospective cohort study conducted at five teaching hospitals in the United States between 1989 and 1994. Participants in this study were hospitalized patients 18 years of age or older with known liver metastases who had been diagnosed with colorectal cancer at least 1 month earlier. Data were collected by patient interview and chart review at study entry; patients were interviewed again at 2 and 6 months. Data collected by physician interview included estimates of survival and impressions of patients' preferences for cardiopulmonary resuscitation (CPR). Patients and physicians were also asked about discussions about prognosis and resuscitation preferences.

RESULTS

We studied 520 patients with metastatic colorectal cancer (median age 64, 56% male, 80% white, 2-month survival 78%, 6-month survival 56%). Quality of life (62% "good" to "excellent") and functional status (median number of disabilities = 0) were high at study entry and remained so among interviewed survivors at 2 and 6 months. Of 339 patients with available information, 212 (63%) of 339 wanted CPR in the event of a cardiopulmonary arrest. Factors independently associated with preference for resuscitation included younger age, better quality of life, absence of lung metastases, and greater patient estimate of 2-month prognosis. Of the patients who preferred not to receive CPR, less than half had a do-not-resuscitate note or order written. Patients' self-assessed prognoses were less accurate than those of their physicians. Physicians incorrectly identified patient CPR preferences in 30% of cases. Neither patient prognostication nor physician understanding of preferences were significantly better when discussions were reported between doctors and patients.

CONCLUSIONS

A majority of patients with colorectal cancer have preferences regarding end of life care. The substantial misunderstanding between patients and their physicians about prognosis and treatment preferences appears not to be improved by direct communication. Future research focused on enhancing the effectiveness of communication between patients and physicians about end of life issues is needed.

Pyridoxal phosphate binding to wild type, W330F, and C298S mutants of Escherichia coli apotryptophanase: unraveling the cold inactivation

The mechanism of pyridoxal phosphate (PLP) binding to apotryptophanase was investigated using stopped-flow kinetics with wild type (WT), W330F and C298S mutants. Based on the dependence of the rate constants on PLP concentrations for the fast and slow phases detected, two mechanistic schemes were proposed. For the WT and C298S mutant, the slow process is due to an isomerization of the aldimine complex after its formation, and not to the binding to an alternative conformation of the apoenzyme, which is the case proposed for the W330F mutant. It is suggested that during the cold inactivation process a conformational change precedes the aldimine bond cleavage. For the W330F apotryptophanase, another conformational change occurs subsequent to the aldimine bond cleavage.

Resuscitation preferences among patients with severe congestive heart failure: results from the SUPPORT project. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments

BACKGROUND

We sought to describe the resuscitation preferences of patients hospitalized with an exacerbation of severe congestive heart failure, perceptions of those preferences by their physicians, and the stability of the preferences.

METHODS AND RESULTS

Of 936 patients in this study, 215 (23%) explicitly stated that they did not want to be resuscitated. Significant correlates of not wanting to be resuscitated included older age, perception of a worse prognosis, poorer functional status, and higher income. The physician's perception of the patient's preference disagreed with the patient's actual preference in 24% of the cases overall. Only 25% of the patients reported discussing resuscitation preferences with their physician, but discussion of preferences was not significantly associated with higher agreement between the patient and physician. Of the 600 patients who responded to the resuscitation question again 2 months later, 19% had changed their preferences, including 14% of those who initially wanted resuscitation (69 of 480) and 40% of those who initially did not (48 of 120). The physician's perception of the patient's hospital resuscitation preference was correct for 84% of patients who had a stable preference and 68% of those who did not.

CONCLUSIONS

Almost one quarter of patients hospitalized with severe heart failure expressed a preference not to be resuscitated. The physician's perception of the patient's preference was not accurate in about one quarter of the cases. but communication was not associated with greater agreement between the patient and the physician. A substantial proportion of patients who did not want to be resuscitated changed their minds within 2 months of discharge.

Patients discharged against medical advice from a general medicine service

This study compares the demographic features and hospital course of all 472 patients discharged against medical advice from the general medicine service of an urban teaching hospital between 1984 and 1995 and 1,113 control patients discharged with physician approval. In the multivariate analysis, younger age (odds ratio [OR] 0.97 per year; 95% confidence interval [CI] 0.96, 0.98), male gender (OR 1.9; 95% CI 1.4, 2.4), lack of health insurance (OR 2.0; 95% CI 1.3, 3.1), Medicaid applicant or recipient status (OR 2.2; 95% CI 1.6, 3.1), admission through the emergency department (OR 2.2; 95% CI 1.4, 3.5), and lack of a personal attending physician at the time of admission (OR 2.1; 95% CI 1.6, 2.8) increased the odds of discharge against medical advice. Fifty-four percent of patients who left against medical advice were readmitted to the hospital during the study period; 98% were then discharged with physician approval. Patients who left the hospital against medical advice included many disadvantaged individuals without ongoing primary care.

Cleavage of Escherichia coli tryptophan indole-lyase by trypsin at Lys406 affects the transmission of conformational changes associated with monovalent cation activation

Escherichia coli tryptophan indole-lyase (Trpase) is a pyridoxal 5'-phosphate(pyridoxal-P)-dependent enzyme which catalyzes the hydrolytic cleavage of L-tryptophan to indole and ammonium pyruvate. This enzyme is strongly activated by K+ and similar monovalent cations, and the spectrum of the pyridoxal-P cofactor is also affected by pH and cations. Treatment of Trpase with trypsin results in a 20-100-fold decrease in elimination activity, depending on the substrate, concomitant with a change in the relative amounts of the 337 nm and 420 nm forms of the bound pyridoxal-P, and a shift in the lambda(max) from 420 nm to 423 nm. In addition, the pH sensitivity of the pyridoxal-P cofactor is eliminated after trypsin treatment. Nicked Trpase exhibits only fourfold activation by K+, compared with about 50-fold for native enzyme, but the K(A) for K+ is unaffected. Both the native and trypsin-nicked Trpase react with amino acids to form equilibrating mixtures of external aldimine and quinonoid intermediates in rapid-scanning stopped-flow experiments. However, the rate constant for quinonoid intermediate formation from L-tryptophan is reduced by at least 400-fold by treatment with trypsin. In contrast, the rate constant for formation of quinonoid intermediates of L-alanine and S-ethyl-L-cysteine is affected only twofold or less by trypsin treatment. The site of trypsin cleavage was identified by electrospray-ionization mass spectrometry as Lys406, which is predicted to lie on a flexible surface loop. Some active-site residues, particularly Arg419, which is predicted by sequence similarity to be the substrate alpha-carboxylate-binding site, and His463, are located in the sequence between Lys406 and the C-terminus. Hence, cleavage of the peptide bond of E. coli Trpase at Lys406 probably affects the change from active to inactive conformations that normally takes place in the presence of activating monovalent cations.

High-efficiency incorporation in vivo of tyrosine analogues with altered hydroxyl acidity in place of the catalytic tyrosine-14 of Delta 5-3-ketosteroid isomerase of Comamonas (Pseudomonas) testosteroni: effects of the modifications on isomerase kinetics

Versions of the Y55F/Y88F modified form of Delta 5-3-ketosteroid isomerase in which the active-site tyrosine-14 is replaced by 2-fluorotyrosine, 3-fluorotyrosine, and 2,3-difluorotyrosine, amino acids having progressively greater acidity of their phenolic hydroxyls, have been expressed in an Escherichia coli host and purified to high homogeneity. The steady-state kinetic properties of Y55F/Y88F KSI and its fluorotyrosine modified forms have been determined. The mechanistic implications of the results are presented and discussed.

The catalytic mechanism of kynureninase from Pseudomonas fluorescens: evidence for transient quinonoid and ketimine intermediates from rapid-scanning stopped-flow spectrophotometry

The reaction of Pseudomonas fluorescens kynureninase with L-kynurenine and L-alanine has been examined using rapid-scanning stopped-flow spectrophotometry. Mixing kynureninase with 0.5 mM L-kynurenine results in formation of a quinonoid intermediate, with lambdamax = 494 nm, within the dead time (ca. 2 ms) of the stopped-flow mixer. This intermediate then decays rapidly, with k = 743 s-1, and this rate constant is reduced to 347 s-1 in [2H]H2O, suggesting that protonation of this intermediate by a solvent exchangeable proton takes place. Rapid quench experiments demonstrate that covalent changes in the cofactor occur, as pyridoxal 5'-phosphate is converted to pyridoxamine 5'-phosphate in about 30 mol % within 5 ms after mixing. Under single turnover conditions in the reaction of kynureninase with l-kynurenine, a transient shoulder absorbing at 335 nm is observed that may be a pyruvate ketimine intermediate. In contrast, the reaction of kynureninase with 0.5 mM l-kynurenine in the presence of 10 mM benzaldehyde results in the formation of a quinonoid intermediate (k = 67.4 s-1) with a very strong absorbance peak at 496 nm. The reaction of L-alanine with kynureninase exhibits the rapid formation (386 s-1 at 0.1 M) of an external aldimine intermediate absorbing at 420 nm, followed by slower formation of a quinonoid intermediate with a peak at 500 nm (k = 2.5 s-1). The 420 nm peak then decays slowly with concomitant formation of a peak at 320 nm corresponding to a pyruvate ketimine. These data demonstrate that quinonoid and ketimine intermediates are catalytically competent in the reaction mechanism of kynureninase, and provide additional support for our proposed mechanism for kynureninase from steady-state kinetic studies [Koushik, S. V., Sundararaju, B., and Phillips, R. S. Biochemistry 1998, 37, 1376-1382].

Relationship between cancer patients' predictions of prognosis and their treatment preferences

CONTEXT

Previous studies have documented that cancer patients tend to overestimate the probability of long-term survival. If patient preferences about the trade-offs between the risks and benefits associated with alternative treatment strategies are based on inaccurate perceptions of prognosis, then treatment choices may not reflect each patient's true values.

OBJECTIVE

To test the hypothesis that among terminally ill cancer patients an accurate understanding of prognosis is associated with a preference for therapy that focuses on comfort over attempts at life extension.

DESIGN

Prospective cohort study.

SETTING

Five teaching hospitals in the United States.

PATIENTS

A total of 917 adults hospitalized with stage III or IV non-small cell lung cancer or colon cancer metastatic to liver in phases 1 and 2 of the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT).

MAIN OUTCOME MEASURES

Proportion of patients favoring life-extending therapy over therapy focusing on relief of pain and discomfort, patient and physician estimates of the probability of 6-month survival, and actual 6-month survival.

RESULTS

Patients who thought they were going to live for at least 6 months were more likely (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.8-3.7) to favor life-extending therapy over comfort care compared with patients who thought there was at least a 10% chance that they would not live 6 months. This OR was highest (8.5; 95% CI, 3.0-24.0) among patients who estimated their 6-month survival probability at greater than 90% but whose physicians estimated it at 10% or less. Patients overestimated their chances of surviving 6 months, while physicians estimated prognosis quite accurately. Patients who preferred life-extending therapy were more likely to undergo aggressive treatment, but controlling for known prognostic factors, their 6-month survival was no better.

CONCLUSIONS

Patients with metastatic colon and lung cancer overestimate their survival probabilities and these estimates may influence their preferences about medical therapies.

Cold inactivation and dissociation into dimers of Escherichia coli tryptophanase and its W330F mutant form

The kinetics and mechanism of reversible cold inactivation of the tetrameric enzyme tryptophanase have been studied. Cold inactivation is shown to occur slowly in the presence of K+ ions and much faster in their absence. The W330F mutant tryptophanase undergoes rapid cold inactivation even in the presence of K+ ions. In all cases the inactivation is accompanied by a decrease of the coenzyme 420-nm CD and absorption peaks and a shift of the latter peak to shorter wavelengths. The spectral changes and the NaBH4 test indicate that cooling of tryptophanase leads to breaking of the internal aldimine bond and release of the coenzyme. HPLC analysis showed that the ensuing apoenzyme dissociates into dimers. The dissociation depends on the nature and concentration of anions in the buffer solution. It readily occurs at low protein concentrations in the presence of salting-in anions Cl-, NO3- and I-, whereas salting-out anions, especially HPO4(2-), hinder the dissociation. K+ ions do not influence the dissociation of the apoenzyme, but partially protect holotryptophanase from cold inactivation. Thus, the two processes, cold inactivation of tryptophanase and dissociation of its apoform into dimers exhibit different dependencies on K+ ions and anions.

Antimalarial activity of unsaturated putrescine derivatives

(E)-1,4-Diaminobut-2-ene dihydrochloride 1 (unsaturated putrescine) and some N-substituted derivatives of 1 have strong antifungal activity against a variety of plant pathogens. A series of N-alkylated putrescine derivatives was synthesised and evaluated for antimalarial activity in vitro against the asexual, intraerythrocytic stages of Plasmodium falciparum. (E)-N,N,N',N'-Tetraethyl-1,4-diaminobut-2-ene dihydrochloride 3 was the most active N-alkylated putrescine tested. Enhanced in-vitro activity was evident with the N,N'-bisbenzyl derivatives 7 and 11. Useful activity in vivo was observed only when the 7-chloroisoquinolyl moiety was present, as in 12 (an unsaturated analogue of chloroquine).

Patient empowerment and feedback did not decrease pain in seriously ill hospitalized adults

We tested a nurse clinician-mediated intervention to relieve pain in a group of seriously ill hospitalized adults using a randomized controlled trial at five tertiary care academic centers in the US. The study included 4804 patients admitted between January 1992 and January 1994 with one or more of nine high mortality diagnoses; 2652 were allocated to the intervention and 2152 to usual care. Specially-trained nurse clinicians assessed patients' pain, educated them and their families about pain control, empowered patients to expect pain relief, informed patients' nurses and physicians about level of pain and suggested or used other pain management resources. Patients' pain was determined from hospital interviews with patients and surrogates. Pain 2 and 6 months later or after death and satisfaction with its control at all time periods were also assessed. All analyses were adjusted for baseline risk of being in pain and propensity to be in the intervention group. Overall, 50.9% of patients reported some pain. After adjustment for other variables associated with pain, comparing the intervention to the control group, there was not a statistically significant difference in level of pain (OR for higher levels of pain 1.15; CI 1.00-1.32) or satisfaction with control of pain during the hospitalization (OR for higher levels of pain 1.12; CI 0.91-1.39), 2 or 6 months after discharge, or during the last 3 days of life. A multifaceted intervention using information, empowerment, advocacy, counseling and feedback was ineffective in ameliorating pain in seriously ill patients. Control of pain in these patients remains an important problem. More intensive pain treatment strategies addressing the needs of seriously ill hospitalized adults must be evaluated.

Health values of hospitalized patients 80 years or older. HELP Investigators. Hospitalized Elderly Longitudinal Project

CONTEXT

Health values (utilities or preferences for health states) are often incorporated into clinical decisions and health care policy when issues of quality vs length of life arise, but little is known about health values of the very old.

OBJECTIVE

To assess health values of older hospitalized patients, compare their values with those of their surrogate decision makers, investigate possible determinants of health values, and determine whether health values change over time.

DESIGN

A prospective, longitudinal, multicenter cohort study.

SETTING

Four academic medical centers.

PARTICIPANTS

Four hundred fourteen hospitalized patients aged 80 years or older and their surrogate decision makers who were interviewed and understood the task.

MAIN OUTCOME MEASURES

Time-trade-off utilities, reflecting preferences for current health relative to a shorter but healthy life.

RESULTS

On average, patients equated living 1 year in their current state of health with living 9.7 months in excellent health (mean [SD] utility, 0.81 [0.28]). Although only 126 patients (30.7%) rated their current quality of life as excellent or very good, 284 (68.6%) were willing to give up at most 1 month of 12 in exchange for excellent health (utility > or =0.92). At the other extreme, 25 (6.0%) were willing to live 2 weeks or less in excellent health rather than 1 year in their current state of health (utility < or =0.04). Patients were willing to trade significantly less time for a healthy life than their surrogates assumed they would (mean difference, 0.05; P=.007); 61 surrogates (20.3%) underestimated the patient's time-trade-off score by 0.25 (3 months of 12) or more. Patients willing to trade less time for better health were more likely to want resuscitation and other measures to extend life. Time-trade-off score correlated only modestly with quality-of-life rating (r=0.28) and inversely with depression score (r=-0.27), but there were few other clinical or demographic predictors of health values. When patients who survived were asked the time-trade-off question again at 1 year, they were willing to trade less time for better health than at baseline (mean difference, 0.04; P=.04).

CONCLUSION

Very old hospitalized patients who could be interviewed were able, in most cases, to have their health values assessed using the time-trade-off technique. Most patients were unwilling to trade much time for excellent health, but preferences varied greatly. Because proxies and multivariable analyses cannot gauge health values of elderly hospitalized patients accurately, health values of the very old should be elicited directly from the patient.

The catalytic mechanism of kynureninase from Pseudomonas fluorescens: insights from the effects of pH and isotopic substitution on steady-state and pre-steady-state kinetics

The effects of pH and isotopic substitution of substrate and solvent on the reaction of kynureninase from Pseudomonas fluorescens have been determined. The pH dependence of kcat/Km for L-kynurenine is bell-shaped, with apparent pKa's of 6.25 +/- 0.05 on the acidic limb and 8.9 +/- 0.1 on the basic limb, and with a pH-dependent value of kcat/Km of 2 x 10(5) M-1 s-1. The pH dependence of kcat/Km for 3-hydroxykynurenine is also bell-shaped, with apparent pKa's of 6.49 +/- 0.07 and 8.55 +/- 0.09, and with a pH-dependent value of 2.5 x 10(3) M-1 s-1. The kcat for L-kynurenine decreases at acidic pH values, with an apparent pKa of 6.43 +/- 0.06 and a pH-dependent value of 7 s-1. The solvent kinetic isotope effect on kcat for the reaction of kynurenine in [2H]H2O is 6.56 +/- 0.59, whereas there is no normal kinetic isotope effect on kcat/Km, at pH 8.1. The proton inventory of kcat fits very well to the Gross-Butler equation, with x = 0.825 +/- 0.08, suggesting that only a single proton is transferred in the rate-determining step. In contrast, there is no significant kinetic isotope effect on either kcat or kcat/Km with alpha-[2H]-L-kynurenine as the substrate. There is a "burst" of anthranilate (0.7 mol/mol of enzyme) formed in the pre steady state of the reaction of kynureninase, with a rate constant of 54 s-1 which is not affected by [2H]H2O. The partition ratio of alanine to pyruvate formation is 2.3 x 10(4) in H2O and 6.9 x 10(3) in [2H]H2O. Taken together, these data indicate that the rate-limiting step in the reaction of kynureninase occurs subsequent to the first irreversible step, which is anthranilate release, is general base catalyzed, and involves transfer of only a single proton. On the basis of these observations, we propose that the rate-limiting step in the reaction of kynureninase is C-4' deprotonation of the pyruvate pyridoxamine 5'-phosphate ketimine intermediate.

Relationship of body mass index to subsequent mortality among seriously ill hospitalized patients. SUPPORT Investigators. The Study to Understand Prognoses and Preferences for Outcome and Risks of Treatments

OBJECTIVE

To determine if body mass Index (BMI = weight [kg]/height [m]2), predictive of mortality in longitudinal epidemiologic studies, was also predictive of mortality in a sample of seriously ill hospitalized subjects.

DESIGN

Prospective, multicenter study.

SETTING

Five tertiary care medical centers in the United States.

PATIENTS

Patients > or = 18 yrs of age who had one of nine illnesses of sufficient severity to anticipate a 6-month mortality rate of 50% were enrolled at five participating sites in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were asked their current height and weight as part of the demographic data. Stratifying body mass index by percentile rank (< or = 15, 15 to 85, and > or = 85th percentiles), risk ratios for mortality were calculated by Cox Proportional Hazards using the 15th to 85th percentile of body mass index as the reference group while controlling for multiple variables such as prior weight loss, albumin, and Acute Physiology Score. A body mass index in the < or = 15th percentile was associated with an excess risk of mortality (risk ratio = 1.23; p < .001) within 6 months. High body mass index (> or = 85th percentile) was not significantly related to risk of mortality.

CONCLUSIONS

Body mass index, a simple anthropometric measure of nutrition employed in community epidemiologic studies, has now been demonstrated to be a predictor of mortality in an acutely ill population of adults at five different tertiary centers. Even when controlling for multiple disease states and physiologic variables and removing from the analysis all patients with significant prior weight loss, a body mass index below the 15th percentile remained a significant and independent predictor of mortality. Examination of patient vs. proxy data did not change the results. Future studies examining variables predictive of mortality should include body mass index, even in acutely ill populations with a poor probability of survival.