Large scale identification of genes involved in cell surface biosynthesis and architecture in Saccharomyces cerevisiae.

The sequenced yeast genome offers a unique resource for the analysis of eukaryotic cell function and enables genome-wide screens for genes involved in cellular processes. We have identified genes involved in cell surface assembly by screening transposon-mutagenized cells for altered sensitivity to calcofluor white, followed by supplementary screens to further characterize mutant phenotypes. The mutated genes were directly retrieved from genomic DNA and then matched uniquely to a gene in the yeast genome database. Eighty-two genes with apparent perturbation of the cell surface were identified, with mutations in 65 of them displaying at least one further cell surface phenotype in addition to their modified sensitivity to calcofluor. Fifty of these genes were previously known, 17 encoded proteins whose function could be anticipated through sequence homology or previously recognized phenotypes and 15 genes had no previously known phenotype.

Tests of preferential independence in the QALY model.

The author presents evidence for the descriptive adequacy of the quality-adjusted life years (QALY) model as applied to health profiles. One important assumption of the model is preferential independence: if two profiles have the same health state during year X, then preference between them does not switch if the level of health changes during year X. In experiment 1, 30-year health profiles were used to perform 27 empirical tests of independence with 98 subjects. Independence was reliably satisfied in all 27 tests. In experiment 2, 15 additional tests were conducted. These tests had been specifically designed to be more sensitive to independence violations, but independence was still mostly satisfied. In both experiments, the conclusions about independence hold regardless of what discount rate is used. These results act as a "lower bound" on the validity of the QALY model for health profiles.

Effects on preferences of violations of procedural invariance.

BACKGROUND: In studies of health preferences, utilities for hypothetical health states cannot always be successfully measured. One marker for unsuccessful measurement is violation of "procedural invariance": when the ranking of two health states varies across assessment procedures. Using preference values based on unsuccessful measurement may result in misinterpretation of patients' attitudes about health. OBJECTIVE: The authors sought to determine whether people who violated procedural invariance had different preferences than people who satisfied it. METHODS: They performed secondary analyses of three completed studies that used the same two assessment procedures, identifying participants who violated procedural invariance and comparing the mean standard gamble (SG) and visual analog scale (VAS) scores of violators and satisfiers. PARTICIPANTS: Experiment 1, 30 healthy volunteers and 30 patients with cardiac arrhythmias; experiment 2, 139 patients with depressive illness; experiment 3, 98 family members of patients with schizophrenia. RESULTS: Rates of violation of procedural invariance ranged from 16% to 32%. Violation of procedural invariance was not associated with age, education level, race, or gender. Subjects with violations of procedural invariance had, in general, less ability to discriminate among states and less reliable VAS and SG measurements, and sometimes had different mean SG and VAS values. CONCLUSIONS: Violation of procedural invariance of preferences across scaling methods may be a signal for failure of the measurement process. Researchers should test for procedural invariance and consider reporting data separately for satisfiers and violators.

Health values and prospect theory.

Health values are important components of medical decisions. Experimental data suggest that people value health in complex and dynamic ways. Prospect theory is a descriptive theory of choice that may accurately characterize how people assign values to health states. The authors first provide background on prospect theory and how it can be applied to health values. Next, they review the relevant health research and find mixed support for prospect theory. Last, they discuss implications of prospect theory for cost-effectiveness analysis. The application of prospect theory to health deserves further research because it may help clarify the link between health and values.

Posterior tibial tendon dysfunction: secondary MR signs.

We evaluated four potential secondary magnetic resonance imaging signs to aid in clinical diagnosis of posterior tibial tendon (PTT) tears. Seventy-one ankles (25 PTT tears and 46 controls) were evaluated for the following secondary signs: (1) PTT sheath fluid, (2) a distal tibial spur located just anterior to the PTT, (3) unroofing of the talus, and (4) "bone bruise"--like medullary lesions. Two musculoskeletal radiologists rated their confidence using a scale and were compared for level of agreement. The presence of PTT sheath fluid had modest specificity and fair to moderate sensitivity. Tibial spurring and unroofing of the talus had excellent specificity and fair sensitivity. Bone bruise-like lesions were commonly seen in cases and controls. Examination of divergence of opinion between the two radiologists revealed pitfalls in interpretation of PTT sheath fluid and bone bruise-like lesions, which were commonly the result of adjacent vessels and inhomogeneous fat saturation, respectively. We conclude that secondary signs of PTT tears with high specificities include unroofing of the talus, tibial spurring, and PTT sheath fluid.

HEDIS, what is it? What does it mean to me? How does it affect my practice?

Collection of data to allow for fact based comparison of health coverage is needed. While the intent is commendable, one must contemplate how to deal with the stream of auditors coming into the office Another issue, proposed to be addressed in the 1996 version, is adjustment of the data for severity of illness. Physician-patient populations are not exactly alike and require severity adjustments to enable valid comparison. Results of data analysis should be shared with the physician. Clarification with each health plan is necessary to ascertain if the analyzed data will be used in a punitive manner (deselection) or in a true CQI (continuous quality improvement) process to allow for identification of weakness and subsequent improvement. Hopefully in the future it will be possible for HEDIS data to be collected by one organization with subsequent distribution of the information to the respective health plans. Not only would this decrease intrusions into daily operation of a medical practice, it would also result in a standardization of collection methodology among all health plans. Until the HEDIS process matures, it may be wise to address some of these concerns in the contract between the physician and health plan. HEDIS can be of benefit not only to employers, but to everyone involved in the health care system--purchasers, patients, and physicians. The HEDIS development process must be closely monitored to be certain data collection is consistent ant reliable, the data collected is meaningful, and the data analysis results are used to improve health care quality--not just for cost control and health planning.

Making health care safer II: an updated critical analysis of the evidence for patient safety practices.

OBJECTIVES: To review important patient safety practices for evidence of effectiveness, implementation, and adoption. DATA SOURCES: Searches of multiple computerized databases, gray literature, and the judgments of a 20-member panel of patient safety stakeholders. REVIEW METHODS: The judgments of the stakeholders were used to prioritize patient safety practices for review, and to select which practices received in-depth reviews and which received brief reviews. In-depth reviews consisted of a formal literature search, usually of multiple databases, and included gray literature, where applicable. In-depth reviews assessed practices on the following domains: • How important is the problem? • What is the patient safety practice? • Why should this practice work? • What are the beneficial effects of the practice? • What are the harms of the practice? • How has the practice been implemented, and in what contexts? • Are there any data about costs? • Are there data about the effect of context on effectiveness? We assessed individual studies for risk of bias using tools appropriate to specific study designs. We assessed the strength of evidence of effectiveness using a system developed for this project. Brief reviews had focused literature searches for focused questions. All practices were then summarized on the following domains: scope of the problem, strength of evidence for effectiveness, evidence on potential for harmful unintended consequences, estimate of costs, how much is known about implementation and how difficult the practice is to implement. Stakeholder judgment was then used to identify practices that were "strongly encouraged" for adoption, and those practices that were "encouraged" for adoption. RESULTS: From an initial list of over 100 patient safety practices, the stakeholders identified 41 practices as a priority for this review: 18 in-depth reviews and 23 brief reviews. Of these, 20 practices had their strength of evidence of effectiveness rated as at least "moderate," and 25 practices had at least "moderate" evidence of how to implement them. Ten practices were classified by the stakeholders as having sufficient evidence of effectiveness and implementation and should be "strongly encouraged" for adoption, and an additional 12 practices were classified as those that should be "encouraged" for adoption. CONCLUSIONS: The evidence supporting the effectiveness of many patient safety practices has improved substantially over the past decade. Evidence about implementation and context has also improved, but continues to lag behind evidence of effectiveness. Twenty-two patient safety practices are sufficiently well understood, and health care providers can consider adopting them now.

The patient survey as data source for CQI and risk management.

Improving communication between patients and providers is important for several reasons. Survey tools provide a useful approach to enhancing patient-provider communication. Combined with clear and concise verbal communication, information obtained through the use of survey tools provides a comprehensive databank of individualized information for delivery of patient-centered care within efficient time parameters.

Dynamic unilateral distraction fixation: surgical management of tibial pilon fractures.

The tibial pilon fracture is a severe injury that can result in disastrous complications. Articulated unilateral external fixation provides an alternate method for the surgical treatment of intra-articular fractures of the distal tibia. This technique provides early mobilization of the ankle joint, stabilizes the fracture site, and through distraction prevents collapse and displacement of the fracture fragments.

The antiglide plate for the Danis-Weber type-B fibular fracture: a review of 71 cases.

The authors present a retrospective study of 71 fractures seen in 70 patients who had sustained the Danis-Weber type-B fibular fracture. All patients had the fractures fixated with the posterior antiglide plate. Of the 71 cases studied, 2 developed peroneal tendonitis. No other type of complication related specifically to the antiglide plate was noted. Because of the very low incidence of complications and good biomechanical strength, the authors recommend the antiglide plate for the fixation of type-B fibular fracture.

Lisfranc arthrodesis for chronic pain: a cannulated screw technique.

Nine patients with injury to the tarsometatarsal joint underwent fusion with cannulated screw fixation after conservative treatment had failed. Symptoms consisted of localized pain, forefoot abduction, and progressive collapse of the medical column. Early diagnosis and treatment were associated with a better functional outcome. The technique involved either a single or double incisional approach, resection of joints, reduction and fixation with cannulated cancellous screws. A total of 43 joints were fused: 37 tarsometatarsal joints and 6 tarsal joints. A partial Lisfranc joint complex fusion (medial three joints) was performed in four patients and a total joint complex fusion was performed in five patients. Intertarsal fusion was performed when pathologic change was evident. A cannulated screw was used to fixated 40 of the 43 joints fused. Reduction was performed prior to arthrodesis, when significant fracture-dislocation had occurred. The cannulated self-tapping cancellous screw technique provides a method of reduction that decreases technical difficulty while providing compression across the fusion site. After an average follow-up of 29 months (range 20 to 36 months), seven patients (78%) rated their outcome as good. One patient had a fair result (11%), and one patient had a poor result (11%).

Health profile preferences of hepatitis C patients.

The side effects of interferon-alpha for chronic hepatitis C are well-known. Patients may differ with respect to their tolerance of these side effects and also with respect to their individual preferences. We administered a brief questionnaire to 67 outpatients with hepatitis C virus infection. Patients were asked to make hypothetical choices between six-month profiles of health. The results were as follows: (1) patients preferred to expedite rather than postpone intervals of poor health; (2) preferences of patients with low quality-of-life were quite similar to preferences of healthier patients; (3) patients' choices satisfied transitivity; (4) patients' choices satisfied preferential independence; and (5) patients gave a variety of reasons for their choices. These results corroborate other investigations of health preferences, and serve to introduce the field of preference elicitation to gastroenterologists.