Upregulation of the ERG11 gene in Candida krusei by azoles

BACKGROUND AND THE PURPOSE OF THE STUDY

Candida species are the agents of local and systemic opportunistic infections and have become a major cause of morbidity and mortality in the last few decades. Azole resistance in Candida krusei (C. krusei) species appears to be the result of gene alterations in relation to the ergosterol biosynthesis pathway, as well as efflux pumps. The main objective of this study was to examine the RNA expression of ERG11 in C. krusei which had been identified to be resistance to azoles.

METHODS

The ERG11 mRNA expression was investigated in four Iranian clinical isolates of C. krusei, which were resistant to fluconazole and itraconazole by a semiquantitative RT-PCR.

RESULTS

The mRNA expression levels were observed in all four isolates by this technique. Furthermore, it was found that ERG11 expression levels vary among four representative isolates of C. krusei. Although DNA sequencing revealed no significant genetic alteration in the ERG11 gene, one heterozygous polymorphism was observed in two isolates, but not in others. This polymorphism was found in the third base of codon 313 for Thr (ACT>ACC).

MAJOR CONCLUSION

Even though such a polymorphism creates a new Ear1 restriction site, no significant effect was found on the resistance of C. krusei to azoles. RESULTS of this investigation are consistent with previous studies and may provide further evidence for the genetic heterogeneity and complexity of the ergosterol biosynthetic pathway or efflux pumps.

Dual-model automatic detection of nerve-fibres in corneal confocal microscopy images

Corneal Confocal Microscopy (CCM) imaging is a non-invasive surrogate of detecting, quantifying and monitoring diabetic peripheral neuropathy. This paper presents an automated method for detecting nerve-fibres from CCM images using a dual-model detection algorithm and compares the performance to well-established texture and feature detection methods. The algorithm comprises two separate models, one for the background and another for the foreground (nerve-fibres), which work interactively. Our evaluation shows significant improvement (p approximately 0) in both error rate and signal-to-noise ratio of this model over the competitor methods. The automatic method is also evaluated in comparison with manual ground truth analysis in assessing diabetic neuropathy on the basis of nerve-fibre length, and shows a strong correlation (r = 0.92). Both analyses significantly separate diabetic patients from control subjects (p approximately 0).

Haptic Effects of Surgical Teleoperator Flexibility

Minimally invasive surgery systems typically involve thin and cable-driven surgical instruments. This introduces link and joint flexibility in the slave robot of a master—slave teleoperation system, reducing the effective stiffness of the slave and the transparency of teleoperation. In this paper, we analyze transparency under slave link and joint flexibility (tool flexibility). We also evaluate the added benefits of using extra sensors at the tip of the flexible robot. It is shown that tip velocity (or position) feedback improves free-space position tracking performance in the presence of robot flexibility. Also, when the interaction forces with an environment are measured by a force sensor and fed back to the user’s hand, tip velocity feedback improves hard-contact force tracking performance. During a hard contact task, tip velocity feedback can also eliminate the transmission of robot flexibility to the user’s hand.

The Neuropad test: a visual indicator test for human diabetic neuropathy

AIMS/HYPOTHESIS

The commercially available Neuropad test was developed as a simple visual indicator test to evaluate diabetic neuropathy. It uses a colour change to define the integrity of skin sympathetic cholinergic innervation. We compared the results of Neuropad assessment in the foot with established measures of somatic and autonomic neuropathy.

METHODS

Fifty-seven diabetic patients underwent Neuropad assessment, quantitative sensory and autonomic function testing, and evaluation of intra-epidermal nerve fibre density in foot skin biopsies.

RESULTS

Neuropad responses correlated with the neuropathy disability score (r(s)=0.450, p<0.001), neuropathic symptom score (r(s)=0.288, p=0.03), cold detection threshold (r(s)=0.394, p = 0.003), heat-as-pain perception threshold visual analogue score 0.5 (r(s)=0.279, p=0.043) and deep-breathing heart rate variability (r(s)= -0.525, p<0.001). Intra-epidermal nerve fibre density (fibres/mm) compared with age- and sex-matched control subjects (11.06+/-0.82) was non-significantly reduced (7.37+/-0.93) in diabetic patients with a normal Neuropad response and significantly reduced in patients with a patchy (5.01+/-0.93) or absent (5.02+/-0.77) response (p=0.02). The sensitivity of an abnormal Neuropad response in detecting clinical neuropathy (neuropathy disability score >or=5) was 85% (negative predictive value 71%) and the specificity was 45% (positive predictive value 69%).

CONCLUSIONS/INTERPRETATION

The Neuropad test may be a simple indicator for screening patients with diabetic neuropathy.

Tool/tissue interaction feedback modalities in robot-assisted lump localization

Providing a surgeon with information regarding contacts made between tools and tissue during robot-assisted interventions can improve task efficiency and reliability. It is hypothesized that various modalities of contact feedback have the potential to enhance performance in a robot-assisted minimally invasive environment. In this paper, (kinesthetic) haptic feedback is compared with visual feedback of haptic information in terms of several performance metrics. Using a haptics-capable master-slave test-bed for endoscopic surgery, experiments involving a lump localization task are conducted and the performance of human subjects is compared for these two modalities of contact feedback. It is shown that the two feedback modalities result in comparable localization accuracies--an advantage of visual haptic feedback due to the lower system complexity required--while the task completion times are significantly shorter with haptic feedback.

Comparative susceptibility of cypermethrin in Ornithodoros lahorensis Neuman and Argas persicus Oken (Acari: Argasidae) field populations

The toxicity of cypermethrin was determined in five different soft tick strains of Argas persicus Oken and Ornithodoros lahorensis Neuman by topical application method. The O. lahorensis Bij, O. lahorensis west O1, O. lahorensis Mesh, A. persicus Lor, A. persicus West Ap strains were collected from Bijar, Kurdistan province, Takab, Western Azerbaijan province, Meshkinshar, Ardebil province, Khoramabad, Lorestan province, Takab, Western Azerbaijan province of different areas of Islamic Republic of Iran, respectively during 2004 and 2005. In the topical application bioassay, the average LD50 of O. lahorensis Bij, West O1, Mesh and A. reflexus Lor and West AP strains were 0.03, 0.04, 1.7, 0.7 and 1.7 microg tick(-1), respectively and the steep slopes of dose-response curves indicated that the field population of these soft tick strains were homogenous in response to cypermethrin. Comparison of the resistance ratio of collected strains with susceptible strain showed a resistance ratio of 56.7 and 2.4-folds for cypermethrin in O. lahorensis Mesh and A. reflexus West Ap strains, whereas the O. lahorensis West O1 completely susceptible to cypermethrin.

Fludarabine and busulfan as a myeloablative conditioning regimen for allogeneic stem cell transplantation in high- and standard-risk leukemic patients

Busulfan and cyclophosphamide (BuCy) are currently the most widely used myeloablative regimen to treat malignancies with allogeneic stem cell transplantation. Fludarabine has considerable efficacy in both immunosuppression and tumor cells killing with a minimal extramedullary toxicity. We evaluated the efficacy of 40 mg/m(2) fludarabine i.v. for 5 days and busulfan 4 mg/kg/day p.o. for 4 days as myeloablative conditioning regimen in 70 patients (median age 24 years) with acute leukemia or chronic phase of myelogenous leukemia. They all had human leukocyte antigen-matched sibling donors. The patients received 10 mug/kg granulocyte colony stimulating factor (GCSF), 24 h after stem cell infusion until engraftment occurred. Graft-versus-host disease (GVHD) prophylaxis included 3 mg/kg cyclosporine-A i.v. from day -2 to +6 followed by 12 mg/kg p.o. until day +60. The median time of neutrophil recovery (>0.5 x 109/l) and platelet recovery (>20 x 109/l) were 10 and 12 days, respectively. Mucositis (93%) and hepatic toxicity (16%) resolved with conservative therapy. The incidence of acute GVHD grade I-II and III-IV were 38.6 and 15.7% respectively. Overall survival and disease-free survival were 71 and 64% respectively with 17 months median follow-up for surviving patients. We conclude that FluBu may be used as a substitute for BuCy with almost the same efficacy and with a lower transplant adverse effect but to increase anti-leukemic effects, especially in acute lymphoblastic leukemia patients, it needs some modifications.

The use of power beams in surface modification

This review of surface modification technologies focuses on the use of power beams, that is, lasers and electron beams, to modify polymer surfaces. A novel electron-beam materials processing technique is also described that offers scope for generating new types of surface functionality on metals used to construct stents and implants.

The impact of anti-tumour necrosis factor therapy for rheumatoid arthritis on the use of other drugs and hospital resources in a pragmatic setting

BACKGROUND

Anti-tumour necrosis factor (anti-TNF) therapy has been an important development for the treatment of rheumatoid arthritis (RA) but the impact of its delivery on hospital resources in still emerging.

AIMS

We audited the effect of starting anti-TNF on the use of other anti-rheumatic therapies and hospital resources in a routine secondary care setting.

METHODS

A retrospective study of resource use before and after anti-TNF was conducted. Hospital records of 54 RA patients were studied and data taken from the time of commencing anti-TNF to 1 October 2004 and an equal time period prior to commencing anti-TNF. Identical data were collected for 54 controls not on anti-TNF. Relevant figures were extrapolated to per annum rates. Results were analysed using two-factor ANOVAs comparing the pre- versus post-anti-TNF period. Cases on intravenous (IV) versus subcutaneous (SC) anti-TNF were also compared in separate ANOVAs.

RESULTS

Mean duration of anti-TNF therapy was 17.04 months (range 3.60-42.36). Mean pre- and 3-months post-anti-TNF Disease Activity Scores (DAS28) were 6.93 and 3.88, respectively. Cases were more likely than controls to be on oral prednisolone pre- and post-anti-TNF. Methylprednisolone requirement, number of disease-modifying anti-rheumatic drugs (DMARDs), telephone helpline contacts and duration as an inpatient reduced significantly post-anti-TNF. Day case admissions increased but outpatient appointments decreased only in cases on IV anti-TNF.

CONCLUSIONS

In a pragmatic setting, anti-TNF therapy led to reduced need for steroid injections and other DMARDs, as well as reductions in use of several hospital resources. Wider replication of these findings will be important for planning delivery.

Methods and mechanisms for contact feedback in a robot-assisted minimally invasive environment

Providing a surgeon with information regarding contacts made between instruments and tissue during robot-assisted interventions can improve task efficiency and reliability. In this report, different methods for feedback of such information to the surgeon are discussed. It is hypothesized that various methods of contact feedback have the potential to enhance performance in a robot-assisted minimally invasive environment. To verify the hypothesis, novel mechanisms needed for incorporating contact feedback were designed, including a surgeon-robot interface with full force feedback capabilities and a surgical end-effector with full force sensing capabilities, that are suitable for minimally invasive applications. These two mechanisms were used to form a robotic "master-slave" test bed for studying the effect of contact feedback on the system and user performance. Using the master-slave system, experiments for surgical tasks involving soft tissue palpation were conducted. The performance of the master-slave system was validated in terms of criteria that assess the accurate transmission of task-related information to the surgeon, which is critical in the context of soft tissue surgical applications. Moreover, using a set of experiments involving human subjects, the performance of several users in carrying out the task was compared among different methods of contact feedback.

A novel polymeric coating for enhanced ultrasound visibility of medical devices

A dynamic novel coating, consisting of a hydrophilic polymeric matrix and a bubbling agent, has been developed for precise entry and positioning of needles, and accurate collection of biopsy samples. These coated biopsy needles have been successfully used in in vitro trials. The results are discussed here. Potential application areas include vascular, cardiovascular and orthopaedics.

The relationship of medical, demographic and psychosocial factors to direct and indirect health utility instruments in rheumatoid arthritis

OBJECTIVES

Cost-effectiveness analysis (CEA) is essential for the comparison of treatments for rheumatoid arthritis (RA). CEA centres on accurate measurement of health utility (HU) preferences. Direct measures of HU in RA patients demonstrate weaker correlations with health status (functional disability and pain) than indirect measures. We examined whether demographic and psychosocial factors relate to HU in RA patients.

METHODS

HU was measured for 142 RA patients (76% women; mean age 58.75 yr) directly through standard gamble (SG) and time trade-off (TTO), and indirectly on the EuroQol (EQ-5D). Current pain (100 mm visual analogue scale) and recent functional disability (Health Assessment Questionnaire; HAQ) were assessed. A subsample of 48 provided demographic and psychosocial information (education, employment, marital/family status, knowledge about RA, medication beliefs, desirable responding, social support, optimism, and the Hospital Anxiety and Depression Scale; HADS).

RESULTS

Direct HU had higher means (SG = 0.88, TTO = 0.86) than indirect HU (EQ-5D = 0.52). HAQ functional disability correlated with SG (r = - 0.28), TTO (r = - 0.31) and EQ-5D (r = - 0.67). Current pain correlated with TTO (r = - 0.19) and EQ-5D (r = - 0.36). HADS depression correlated with TTO (r = - 0.35) and EQ-5D (r = - 0.64); HADS anxiety also correlated with EQ-5D (r = - 0.46).

CONCLUSIONS

Demographic and psychosocial factors cannot completely explain either the significant differences between direct and indirect HUs in RA patients or the moderate correlations of direct HUs with health status. Characteristics of the SG and TTO may make them inappropriate for HU assessment and CEA among RA patients.

Multi-sensory force/deformation cues for stiffness characterization in soft-tissue palpation

In the commercially available robot-assisted surgical systems, camera vision constitutes the only flow of data from the patient side to the surgeon side. This paper studies how various modalities for feedback of interaction between a surgical tool and soft tissue can improve the efficiency of a typical surgical task. Utilizing a haptics-enabled master-slave test-bed for minimally invasive surgery, user performance during a telemanipulated soft tissue stiffness discrimination task is compared under visual, haptic, graphical, and graphical plus haptic feedback modes in terms of task success rate and completion time and the amount of energy transfer and consequently trauma to tissue. While no significant difference is found in terms of the task completion times, graphical cueing and visual cueing are found to lead to the highest success rate and the highest risk of tissue damage (proportional to energy), respectively.

Innovation and the medical devices Farady partnership

Demand for development of new generation medical devices has led many governments to support medical-sector research. In the United Kingdom, the Medical Devices Faraday Partnership was created to establish a collaborative network that would enhance the transfer of good ideas into new products and processes. The services it offers medical device manufacturers are outlined here.

Haptic interaction in robot-assisted endoscopic surgery: a sensorized end-effector

Conventional endoscopic surgery has some drawbacks that can be addressed by using robots. The robotic systems used for surgery are still in their infancy. A major deficiency is the lack of haptic feedback to the surgeon. In this paper, the benefits of haptic feedback in robot-assisted surgery are discussed. A novel robotic end-effector is then described that meets the requirements of endoscopic surgery and is sensorized for force/ torque feedback. The endoscopic end-effector is capable of non-invasively measuring its interaction with tissue in all the degrees of freedom available during endoscopic manipulation. It is also capable of remotely actuating a tip and measuring its interaction with the environment without using any sensors on the jaws. The sensorized end-effector can be used as the last arm of a surgical robot to incorporate haptic feedback and/or to evaluate skills and learning curves of residents and surgeons in endoscopic surgery.

Disease progression in amyotrophic lateral sclerosis. Identifying the cost-utility of riluzole by disease stage

This study reports the results of a long-term economic evaluation of riluzole in the treatment of amyotrophic lateral sclerosis (ALS) versus best supportive care in the United Kingdom. The analysis included in this contribution aims to provide an update of the determination of the phase of the disease that is prolonged by riluzole and also to assess the quality of the life extension offered by riluzole by taking into account the patients' utility score. Specifically, the analysis provides a more specific estimate of the cost-utility of riluzole dependent disease stage, thereby providing a useful insight of the cost-effectiveness of therapy. A Markov model was used to assess the cost-effectiveness of riluzole versus best supportive care. Transition possibilities and the distribution of patients by health states were taken from a cohort of 954 patients drawn from a large randomised, double blind, placebo-controlled, multicentre trial between 1992 and 1994. Costs associated with riluzole included the acquisition cost and bi-monthly monitoring for raised ALT levels. Patient assessed utilities were collected by use of the SG technique from two centres (King's, London and Preston) in the UK. Four distinct health states were used corresponding to mild, moderate, severe and terminal states. Applying the Markov model and extending the transitional probabilities using linear interpolation, the base case cost per life year gained was estimated at 15,192 pounds while applying Standard Gamble utility scores, the base case cost per quality-adjusted life-year (QALY) was assessed at 22,086 pounds. Carrying out a probabilistic sensitivity analysis, the cost per QALY was estimated at 22,236 pounds with standard deviation of 612 pounds. The results of the long-term analysis also show that riluzole on average increases survival in ALS patients by 6 months with approximately 5 months of the additional life gained in the early disease states, of which 4 months is spent in disease state 2, where quality of life is relatively high. However, the model is sensitive in the way in which the long-term transitional probabilities are estimated. Using averages of the first nine cycles, the cost per QALY would increase to 33,420 pounds with standard deviation of 972 pounds. Thus, this analysis highlights some of the difficulties associated with extending the short clinical effectiveness data; one way forward would be to obtain long-term observations data for both groups.

The cost utility analysis of riluzole for the treatment of amyotrophic lateral sclerosis in the UK

This study reports the results of a long-term economic evaluation of riluzole in the treatment of amyotrophic lateral sclerosis (ALS) versus best supportive care in the United Kingdom. The aim was to assess the cost implications of the life extension offered by riluzole through cost utility analysis based on patient assessed utilities of different health states.A Markov model was used to assess the cost-effectiveness of Rilutek with best supportive care. Transition possibilities and the distribution of patients by health states were taken from a cohort of 954 patients drawn from a large randomised, double blind, placebo-controlled, multicentre trial between 1992 and 1994 in the first 18 months and used to extrapolate the model to assess the long-term prolongation of life. Four distinct health states were used corresponding to mild, moderate, severe and terminal states. Costs associated with Rilutek included the acquisition cost and bi-monthly monitoring for raised ALT levels. Patient assessed utilities were collected by use of the standard gamble technique. 77 patients were entered into the study from two centres (King's, London and Preston) in the UK. Mean utilities for each of the health states was generated and, given that the data were skewed, a sensitivity analysis was undertaken with the median utility values. The implications of life extension offered by riluzole versus best supportive care were assessed both in terms of life extension projected and quality adjusted survival using patient based utilities. Using the Markov model and the transitional probabilities the base case cost per life year gained was estimated at pound sterlings 14,370 and applying Standard Gamble utility scores, the base case cost per QALY was assessed as pound sterlings 20,904. The effect of discounting costs and benefits altered the cost effectiveness analysis to pound sterlings 17,760 per life year gained while a sensitivity analysis around median or mean scores for the utility weight resulted in a range of pound sterlings 19,020 to pound sterlings 25,794 per QALY gained.

Decision analysis in evidence-based decision making

Many real world decisions have to be made on a limited evidence base, and clinical decisions are at best problematic. We explored some of the reasons why decision making in health care is so complex, and examined how decision analytic techniques might contribute to problem structuring and to implementation of evidence-based practice. We argued that decision analysis could, to some extent, overcome complexity of decision making by a clear structuring of the problem and a formal analysis of the implications of different decisions. Decision-analytic techniques can guide the management of individual patients or can be used to address policy questions about the use of treatment for groups of patients. However, decision analysis is not without its criticisms, e.g. problems are narrowly defined, replacing judgement and dehumanizing care, neglect of process utility and lack of primary data to develop decision analytic models. The development of evidence-based guidelines is a key component of the UK Government's quality strategy led by the National Institute for Clinical Excellence (NICE). However, the guidelines approach may lead to conflict when assessments of the effectiveness of interventions for individuals (whether or not supported by a formal decision analysis) conflict with the recommendations made by NICE for cost and clinical effectiveness for aggregate groups of patients. Decision analysis may or may not help with this but if guidelines are derived from a decision analysis, then the implications of patient preferences should be made clearer. However, decision analysis-derived guidelines will make general recommendations that may not be appropriate for all individuals. Nonetheless, decision analysis does make such implications explicit and propose that the guidelines should be supported by some mechanism for determining individual patient preferences. It will now need to consider whether some of NICE resources should be directed beyond evidence-based guidelines into decision analysis-derived guidelines and into decision analytical techniques to provide support for clinical and cost effective decision making within the patient-clinician encounter.

Diagnosis and management of osteomyelitis. Decision analytic and pharmacoeconomic considerations

Osteomyelitis, or bone infection, is becoming more common, largely because of increases in the use of implanted prosthetic devices in the management of arthritis or fractures. The clinical management of osteomyelitis requires accurate microbiological diagnosis that will identify appropriate antibacterials to which the pathogenic organisms are sensitive. Therapy will largely depend on the type of bacteria, the route by which the bacteria reach the bone, the presence of any orthopaedic devices and the patient's ability to mount an immune response. Consequently, therapy often requires a combination of medical and surgical management. The aim of this review is primarily to assess the impact of different drug regimens on the total cost and to clarify the implications of various treatment options for patients with osteomyelitis. Thus, the review examines the link between the main categories of osteomyelitis and common pathogens, and provides additional comments on the aetiology and epidemiology of the condition. At present, there is a real shortage of high quality evidence to guide the decision-maker through the range of available options. One way to deal with the complexity and uncertainty surrounding the management of osteomyelitis is to develop treatment protocols leading to decision trees which will in turn systematically analyse the options available for treating patients with osteomyelitis. Consequently, we have developed a number of decision trees to show the range of options available and have applied these to the relatively simple problem of route of administration of antibacterials. However, even here the available data allow only relatively crude estimations of the costs and consequences of alternative regimens. Thus, the aim has been to provide structures that may help to set priorities for research based on the expected value of new information. In the absence of evidence, there are broadly 2 alternatives. One is based on selection of the least expensive regimen in the absence of evidence to prove that more expensive options are more effective; patients with multiply resistant staphylococci, for which no effective oral regimen is available, should be treated with intravenous therapy. This is consistent with the UK legal system, which is founded on the so-called Bolam test. The alternative is providing the maximum available treatment; in the US, it is more likely that a doctor will be held negligent for not providing the maximum available treatment, and most standard texts recommend routine use of intravenous therapy for osteomyelitis.

Decision analysis of histamine H2-receptor antagonist maintenance therapy versus Helicobacter pylori eradication therapy: a randomised controlled trial in patients with continuing pain after duodenal ulcer

BACKGROUND

Much has been published on the efficacy and cost effectiveness of Helicobacter pylori eradication treatment as an alternative to histamine H2-receptor antagonist maintenance treatment in peptic ulcer disease. However, most studies have analysed and emphasised H. pylori eradication rates rather than management/control of symptoms and the associated cost savings. Although H. pylori eradication therapy is very successful in clearing the infection, dyspeptic symptoms may persist and management of these can be expensive.

OBJECTIVE

The aim of this study was to assess the cost implications in controlling symptoms using either H2-receptor antagonist maintenance therapy or H. pylori eradication therapy in patients with duodenal ulcer disease.

DESIGN

This was a non-blind, prospective, randomised, parallel-group study comparing maintenance H2-receptor antagonist treatment using ranitidine with H. pylori eradication therapy, with a 1-year follow-up.

SETTING

This was a study of outpatients from general practices in Dundee, Scotland, or the Ninewells Hospital, Dundee, gastroenterology clinic.

PATIENTS AND PARTICIPANTS

119 patients with confirmed duodenal ulcer, free from active ulceration at study entry but positive for H. pylori infection, who were receiving maintenance H2-receptor antagonist therapy.

INTERVENTIONS

Patients were randomised to receive either continuing maintenance therapy with ranitidine (initially 150 mg daily; 58 patients) or H. pylori eradication therapy using an omeprazole/amoxicillin/metronidazole regimen (or omeprazole/clarithromycin if allergic to penicillin).

MAIN OUTCOME MEASURES AND RESULTS

Overall, H. pylori eradication rates were 100% per protocol and 95.1% intention-to-treat. At completion of 1 year of follow-up, 12 of the 61 (19.7%) patients successfully eradicated of H. pylori were still dependent on acid suppression for symptom relief. H. pylori eradication treatment was the least-cost strategy in managing/controlling symptoms at 1 year (168 Pounds vs 210 Pounds per patient; 1996 values). However, over time, post-eradication treatment costs were greater than H2-receptor antagonist therapy costs. Any potential savings were directly related to the proportion of patients needing further treatment post-eradication, the cost of endoscopy and the urea breath test.

CONCLUSIONS

If dyspepsia persists long term, H. pylori eradication treatment may not be the least-cost option for patients with duodenal ulcer.

Aiding clinical decisions with decision analysis

As clinical decision making gets ever more complex, new analytical approaches are being developed to help. Decision analysis is used to structure complex decision problems in an uncertain environment by systematically linking decision choices with expected outcomes. Such models can include the probabilities of outcomes, patient preferences and costs. These models can help to advise about therapeutic avenues. This paper examines the nature of decision analysis, and explores the pitfalls that arise in interpreting the findings from published studies.