Decision analysis in patient care

To help patients to fully participate in shared decision making is becoming an important goal in clinical practice and one which is receiving increasing attention in terms of the requisite skills and technological development. We discuss the potential application of decision analysis-a specific technology that has been introduced into clinical practice but to date only within research contexts-and examine the usefulness and feasibility of the technique for patients, particularly in settings where clinical presentations are diverse and characterised by uncertainty.

Analysis of loss of heterozygosity in lymphoma and leukaemia arising in F1 hybrid mice locates a common region of chromosome 4 loss

Previous studies have identified five lymphoma-related tumour suppressor gene regions on murine chromosome 4. Using detailed allelotype analysis on a range of lympho-haematopoietic tumour types arising in F1 hybrid mice, we now show a consistent pattern of loss of heterozygosity (LOH) which identifies a common region of loss delineated by microsatellites D4Mit21 and D4Mit53 on proximal chromosome 4. This critical segment corresponds to the thymic lymphoma tumour suppressor region 5 (TLSR5) identified in an earlier study. Tumours of this type have also been reported as showing allelic loss from the Trp53 and Ikaros regions on chromosome 11. In the present study, only a small fraction of tumours showed LOH in the Ikaros region, while a minority of lymphomas, but not acute myeloid leukaemias, showed allelic loss of the chromosome 11 segment encoding Trp53. These and other data indicate strongly that the genomic regions identified as showing recurrent LOH depend on the genetic background of the mice. Overall, the results indicate a key role for a tumour suppressor gene(s) encoded in an approximately 3 cM segment on proximal chromosome 4 and provide an experimental basis for the further investigation of the functional role of candidate genes which include Pax5 and Tgfbr1.

Benchmarking using simulated clinical scenarios: a feasibility project

'Benchmarking' clinical practice and integrating such data with national guidelines offers a way of establishing standards for use in clinical governance. We report on a feasibility project for benchmarking clinical practice in one topic area (otitis media) using simulated clinical scenarios. Consistency and variations in clinical management were identified for different scenarios. Participants perceived the process likely to reflect actual practice and effect change in clinical management.

Attenuation of neurotoxicity in cortical cultures and hippocampal slices from E2F1 knockout mice

The E2F1 transcription factor modulates neuronal apoptosis induced by staurosporine, DNA damage and beta-amyloid. We demonstrate E2F1 involvement in neuronal death induced by the more physiological oxygen-glucose deprivation (OGD) in mouse cortical cultures and by anoxia in mouse hippocampal slices. E2F1(+/+) and (-/-) cultures were comparable, in that they contained similar neuronal densities, responded with similar increases in intracellular calcium concentration ([Ca(2+)]i) to glutamate receptor agonists, and showed similar NMDA receptor subunit mRNA expression levels for NR1, NR2A and NR2B. Despite these similarities, E2F1(-/-) cultures were significantly less susceptible to neuronal death than E2F1(+/+) cultures 24 and 48 h following 120-180 min of OGD. Furthermore, the absence of E2F1 significantly improved the ability of CA1 neurons in hippocampal slices to recover synaptic transmission following a transient anoxic insult in vitro. These results, along with our finding that E2F1 mRNA levels are significantly increased following OGD, support a role for E2F1 in the modulation of OGD- and anoxia-induced neuronal death. These findings are consistent with studies showing that overexpression of E2F1 in postmitotic neurons causes neuronal degeneration and the absence of E2F1 decreases infarct volume following cerebral ischemia.

Diabetic foot disorders: a clinical practice guideline. American College of Foot and Ankle Surgeons

Foot ulcerations, infections, and Charcot neuropathic osteoarthropathy are three serious foot complications of diabetes mellitus that can too frequently lead to gangrene and lower limb amputation. Consequently, foot disorders are one of the leading causes of hospitalization for persons with diabetes and can account for expenditures in the billions of dollars annually in the U.S. alone. Although not all foot complications can be prevented, dramatic reductions in their frequency have been obtained through the implementation of a multidisciplinary team approach to patient management. Using this concept, the authors present a Clinical Practice Guideline for diabetic foot disorders based on currently available evidence. The underlying pathophysiology and treatment of diabetic foot ulcers, infections, and the diabetic Charcot foot are thoroughly reviewed. Although these guidelines cannot and should not dictate the standard of care for all affected patients, they are intended to provide evidence-based guidance for general patterns of practice. The goal of a major reduction in diabetic limb amputations is certainly possible if these concepts are embraced and incorporated into patient management protocols.

Changes in plasma progesterone, estrogen, and testosterone concentrations throughout the reproductive cycle in female viviparous blue-tongued skinks, Tiliqua nigrolutea (Scincidae), in Tasmania

Changes in mean plasma concentrations of progesterone (P4), estrogen (E), and testosterone (T) in a captive population of female viviparous skinks, Tiliqua nigrolutea, were examined. Reproductively active and quiescent individuals were present in the population concurrently, allowing a comparison between these two conditions. Mean plasma progesterone concentrations were basal (1-2 ng ml(-1)) until the start of gestation and peaked in the second trimester (12.7 +/- 1.27 ng ml(-1)), before falling significantly prior to parturition. An increase in mean plasma estrogen concentrations occurred coincident with the vitellogenic period; the mean plasma estrogen concentration peaked at 715.1 +/- 106.68 pg ml(-1) shortly before ovulation. Mean plasma testosterone concentrations in reproductively active females peaked in the periovulatory period (6.3 +/- 0.63 ng ml(-1)) and had returned to basal concentrations (<1 ng ml(-1)) 2 weeks later. Changes in mean plasma steroid concentrations were correlated with reproductive condition and are discussed in terms of potential in vivo steroid interactions and the multihormone control of reproduction.

Accuracy and modifying factors of the sonographic estimation of fetal weight in a high-risk population

There have been a number of reviews assessing the accuracy of different methods of sonographic estimation of fetal weight, without identifying any clearly superior equation. In order to optimise accuracy in a high-risk population, we decided to compare some of the most popular early equations with the newer volume-based equations, and to try and identify factors that affect the ability of these equations to estimate fetal weight accurately We collected the scan and delivery details of 192 fetuses born within one week of a sonographic estimation of fetal weight. We then applied three of the most popular equations and two newer volume-based equations to the recorded fetal biometric parameters to assess the performance of each equation overall, and under varying maternal, fetal, and scan conditions. The equations of Shepard, Hadlock A, Hadlock B and Combs produced similar results with systematic (mean) errors in the range 1.2-1.9% and random error characterised by one standard deviation in the range of 8.6-9.5%. Dudley's volume-based equation produced a significant systematic error in the form of a mean error of 7.4%, which corresponds to a mean birthweight (BW) which is 7.4% above the mean estimated fetal weight (EFW). When we stratified the study group by birthweight, Combs' equation produced significant differences in the mean error, (p < 0.00001), that ranged from a mean overestimation in fetal weight of 8.5% for babies with BW < 1000 g to a mean underestimation in fetal weight of 6.2% for babies with BW > 3000 g. Oligohydramnios resulted in a trend towards an increased mean error for all equations which was only statistically significant for Hadlock B. The equations Shepard and Hadlock A performed best in our high-risk population. They produced the smallest systematic errors across the entire study group and were not adversely affected by variations in birthweight, liquor volume, or fetal presentation. The newer, volume-based equations were disappointing, producing large systematic errors. Large random errors in all equations continue to be the Achilles' heel that limit the value of sonographic EFW.

Shared decision making observed in clinical practice: visual displays of communication sequence and patterns

The aim of the study was to examine the communication strategies of general practitioners attempting to involve patients in treatment or management decisions. This empirical data was then compared with theoretical 'competences' derived for 'shared decision making'. The subjects were four general practitioners, who taped conducted consultations with the specific intent of involving patients in the decision-making process. The consultations were transcribed, coded into skill categorizations and presented as visual display using a specifically devised sequential banding

METHOD

The empirical data from these purposively selected consultation from clinicians who are experienced in shared decision making did not match suggested theoretical frameworks. The views of patients about treatment possibilities and their preferred role in decision making were not explored. The interactions were initiated by a problem-defining phase, statements of 'equipoise' consistently appeared and the portrayal of option information was often intermingled with opportunities to allow patients to question and reflect. A decision-making stage occurred consistently after approximately 80% of the total consultation duration and arrangements were consistently made for follow-up and review. Eight of the 10 consultations took more than 11 min - these specific consultations were characterized by significant proportions of time provided for information exchange and patient interaction. The results demonstrate that some theoretical competences are not distinguishable in practice and other stages, not previously described, such as the 'portrayal of equipoise', are observed. The suggested ideal of a shared decision-making interaction will either require more time than currently allocated, or alternative strategies to enable information exchange outside the consultation.

Measuring the involvement of patients in shared decision-making: a systematic review of instruments

We wanted to determine whether research instruments exist which focus on measuring to what extent health professionals involve patients in treatment and management decisions. A systematic search and appraisal of the relevant literature was conducted by electronic searching techniques, snowball sampling and correspondence with field specialists. The instruments had to concentrate on assessing patient involvement in decision-making by observation techniques (either direct or using audio or videotaped data) and contain assessments of the core aspects of 'involvement', namely evidence of patients being involved (explicitly or implicitly) in decision-making processes, a portrayal of options and a decision-making or deferring stage. Eight instruments met the inclusion criteria. But we did not find any instruments that had been specifically designed to measure the concept of 'involving patients' in decisions. The results reveal that little attention has been given to a detailed assessment of the processes of patient involvement in decision-making. The existing instrumentation only includes these concepts as sub-units within broader assessments, and does not allow the construct of patient involvement to be measured accurately. Instruments developed to measure 'patient-centeredness' are unable to provide enough focus on 'involvement' because of their attempt to cover so many dimensions. The concept of patient involvement (shared decision-making; informed collaborative choice) is emerging in the literature and requires an accurate method of assessment.

Diabetic foot disorders. A clinical practice guideline. For the American College of Foot and Ankle Surgeons and the American College of Foot and Ankle Orthopedics and Medicine

Foot ulcerations, infections, and Charcot neuropathic osteoarthropathy are three serious foot complications of diabetes mellitus that can too frequently lead to gangrene and lower limb amputation. Consequently, foot disorders are one of the leading causes of hospitalization for persons with diabetes and can account for expenditures in the billions of dollars annually in the U.S. alone. Although not all foot complications can be prevented, dramatic reductions in their frequency have been obtained through the implementation of a multidisciplinary team approach to patient management. Using this concept, the authors present a Clinical Practice Guideline for diabetic foot disorders based on currently available evidence. The underlying pathophysiology and treatment of diabetic foot ulcers, infections, and the diabetic Charcot foot are thoroughly reviewed. Although these guidelines cannot and should not dictate the standard of care for all affected patients, they are intended to provide evidence-based guidance for general patterns of practice. The goal of a major reduction in diabetic limb amputations is certainly possible if these concepts are embraced and incorporated into patient management protocols.

Presenting risk information--a review of the effects of "framing" and other manipulations on patient outcomes

Discussing risks and benefits of treatments or care options is becoming an increasingly important part of modern health care. This paper reviews the literature about manipulations of risk and benefit information in the clinical setting. There is a paucity of evidence in this field, particularly when examining specific manipulations. Only three categories of manipulation had three or more studies. The available evidence shows that the way information is presented can have significant effects on decisions made. The largest effects are evident when relative risk information is presented, as compared with absolute risk data. In addition, "loss framing" is more effective in influencing screening uptake behaviors than "gain framing" (odds ratio 1.18 [95% confidence interval 1.01-1.38]). There is also a pattern of evidence from studies comparing simpler with more complex information, more data with less, and those comparing numerical with verbal descriptions of risks. These studies suggest that providing more information, and which is more understandable to the patient, is associated with improved patient knowledge and a greater wariness to take treatments or participate in trials. These findings can contribute to efforts to improve communication between professionals and patients.

The mechanical behavior of vascular grafts: a review

The development of intimal hyperplasia (IH) near the anastomosis of a vascular graft to artery is directly related to changes in the wall shear rate distribution. Mismatch in compliance and diameter at the end-to-end anastomosis of a compliant artery and rigid graft cause shear rate disturbances that may induce intimal hyperplasia and ultimately graft failure. The principal strategy being developed to prevent IH is based on the design and fabrication of compliant synthetic or innovative tissue-engineered grafts with viscoelastic properties that mirror those of the human artery. The goal of this review is to discuss how mechanical properties including compliance mismatch, diameter mismatch, Young's modulus and impedance phase angle affect graft failure due to intimal hyperplasia.

Ultrasonographic evaluation of the postpartum uterus

OBJECTIVES

To define the ultrasonographic appearance of the uterus and the uterine cavity, including its contents, in normal women making an uncomplicated postpartum recovery.

METHODS

Forty women were scanned on days 7, 14, and 21 postpartum. At each scan the uterine and cavity volumes were estimated, and the appearance of the uterine cavity contents was documented. The amount and duration of postpartum vaginal bleeding, and method of infant feeding were also recorded.

RESULTS

The mean duration of postpartum bleeding was 24.5 (range 14-45) days. Fifty-one percent (95% confidence interval 34-68) of the subjects scanned at 7 days postpartum, 21%(8-36) at 14 days, and 6%(0.8-20) at 21 days, had an echogenic mass within the uterine cavity. Statistical analysis revealed no difference, in terms of bleeding duration, between women with a uterine cavity echogenic mass noted at 7, 14, or 21 days postpartum, and those without (unpaired t-test, P = 0.42, 0.39, and 0.06). The presence of an echogenic mass was not associated with heavier bleeding at the time of any of the scans (chi-squared test, P = 0.58, 0.56, and 0.28). Statistical analysis revealed no correlation between the duration or amount of bleeding, and the uterine or cavity volume, at any of the three scans.

CONCLUSION

In this study, ultrasound evaluation of the uterine cavity revealed an echogenic mass in 51% of women with normal postpartum bleeding at 7 days, 21% at 14 days, and 6% at 21 days postpartum. This questions the significance of echogenic material within the uterine cavity in the postpartum period.

Shared decision making and the concept of equipoise: the competences of involving patients in healthcare choices

BACKGROUND

Involving patients in healthcare decisions makes a potentially significant and enduring difference to healthcare outcomes. One difficulty (among many) is that the 'involvement' of patients in decisions has been left undefined. It is usually conceptualised as 'patient centredness', which is a broad and variably interpreted concept that is difficult to assess using current tools. This paper attempts to gauge general practitioners' (GPs') attitudes to patient involvement in decision making and their views about the contextual factors, competences, and stages required to achieve shared decisions within consultations.

AIM

To explore and understand what constitutes the appropriate involvement of patients in decision making within consultations, to consider previous theory in this field, and to propose a set of competences (skills) and steps that would enable clinical practitioners (generalists) to undertake 'shared decision making' in their clinical environment.

METHOD

Qualitative study using focus group interviews of key informants.

RESULTS

Experienced GPs with educational roles have positive attitudes to the involvement of patients in decisions, provided the process matches the role individuals wish to play. They perceive some clinical problems as being more suited to a cooperative approach to decision making and conceptualised the existence of professional equipoise towards the existence of legitimate treatment options as an important facilitative factor. A sequence of skills was proposed as follows: 1) implicit or explicit involvement of patients in the decision-making process; 2) explore ideas, fears, and expectations of the problem and possible treatments; 3) portrayal of equipoise and options; 4) identify preferred data format and provide tailor-made information; 5) checking process: understanding of information and reactions (e.g. ideas, fears, and expectations of possible options); 6) acceptance of process and decision making role preference; 7) make, discuss or defer decisions; 8) arrange follow-up.

CONCLUSIONS

These clinicians viewed involvement as an implicit ethos that should permeate medical practice, provided that clinicians respect and remain alert to patients' individual preferred roles in decision making. The interpersonal skills and the information requirements needed to successfully share decisions are major challenges to the clinical consultation process in medical practice. The benefits of patient involvement and the skills required to achieve this approach need to be given much higher priority at all levels: at policy, education, and within further professional development strategies.

Compliance properties of conduits used in vascular reconstruction

BACKGROUND

Compliance mismatch between native artery and prosthetic graft used for infrainguinal bypass is implicated in the aetiology of graft failure. The aim was to quantify the elastic properties of a new compliant poly(carbonate)polyurethane (CPU) vascular graft, and to compare the compliance properties of grafts made from CPU, expanded polytetrafluoroethylene (ePTFE), Dacron and human saphenous vein with that of human muscular artery.

METHODS

A pulsatile flow phantom was used to perfuse vessel and prosthetic graft segments at physiological pulse pressure and flow. Intraluminal pressure was measured using a Millar Mikro-tip catheter transducer and vessel wall motion was determined with duplex ultrasonography using an echo-locked wall-tracking system. Diametrical compliance and a stiffness index were then calculated for each type of conduit over mean pressures ranging from 30 to 100 mmHg by 10-mmHg increments.

RESULTS

The compliance values of CPU and artery (mean over the pressure range) were similar (mean(s.d.) 8.1(0.4) and 8.0(5.9) per cent per mmHg x 10(-2) respectively), although the elastic behaviour of artery was anisotropic unlike CPU, which was isotropic. Dacron and ePTFE grafts had lower compliance values (1.8(1.2) and 1.2(0.3)per cent per mmHg x 10(-2) respectively, averaged over the pressure range). In both these cases, compliance and stiffness differed significantly from that of artery over a mean pressure range of 30-90 mmHg. Human saphenous vein exhibited anisotropic behaviour and, although compliant at low pressure (30 mmHg), was markedly incompliant at higher pressures.

CONCLUSION

Compliant polyurethane grafts offer a greater degree of compliance match than either ePTFE or Dacron.

Changes in the incidence of childhood autism and other autistic spectrum disorders in preschool children from two areas of the West Midlands, UK

The incidence of childhood autism and other autistic spectrum disorders (ASDs) in preschool children was determined for two areas of the West Midlands between 1991 and 1996. Children diagnosed before the age of 5 years and residing within the study areas at diagnosis were detected from the records of four child development centres. The incidence rate per 10,000 children per year for the combined areas was 8.3 for all children with ASDs, 3.5 for classical childhood autism (CA), and 4.8 for other ASDs. Rates were similar in both areas, despite differences in social deprivation and proportions of ethnic minorities. While rates for classical CA increased by 18% per year, a much larger increase (55% per year) was seen for 'other ASDs', suggesting that clinicians are becoming increasingly able and/or willing to diagnose ASDs in preschool children.

Clinical features of lichen sclerosus in men attending a department of genitourinary medicine

OBJECTIVES

To characterise the clinical presentation and response to treatment of lichen sclerosus (LS) in men attending a department of genitourinary medicine.

METHODS

A case note review of all men attending a GUM department over a 32 month period, who had been diagnosed as having LS.

RESULTS

66 men were seen with genital LS. The mean age at diagnosis was 36.5 years but symptoms had been present for up to 10 years before the diagnosis was made. 55 men underwent biopsy and the diagnosis was made histologically in 47 of these men. At the time of presentation 30% of men had no symptoms relating to their LS. All were treated with potent topical steroids and surgery was avoided in nearly all of them.

CONCLUSIONS

LS is not uncommon in men presenting to a GUM department, and is often asymptomatic. The disease responds well to potent topical steroids allowing the normal anatomy to be preserved in most individuals.

The effectiveness of one-to-one risk communication interventions in health care: a systematic review

OBJECTIVES

To assess whether risk-communication interventions are associated with changes in patient knowledge, attitudes, and behaviors, and to identify aspects of these interventions that modify these effects.

DESIGN

Systematic review.

DATA SOURCES

96 studies from the period 1985-1996 retrieved by electronic searching of eight databases, hand searching of four journals, contacting key authors, and reference list searching.

MAIN OUTCOME MEASURES

The effect size of the principal outcome was identified from each study. Outcomes measuring behavioral change were preferred; if these were not available, knowledge, anxiety, or risk perceptions were used, according to the focus of the study. Data were available to calculate the principal effect sizes for 82 of the studies.

ANALYSIS

Meta-regression.

RESULTS

The methodologic qualities of the studies varied. Nevertheless, risk-communication interventions generally had positive (beneficial) effects. Interventions addressing treatment choices were associated with larger effects than were those in other contexts, such as prevention or screening. Interventions using individual risk estimates were associated with larger effects than were those using more general risk information. Two design variables were identified as effect modifiers: randomized controlled trials were associated with smaller effects than other designs, and dichotomous outcomes were associated with larger effects than continuous outcomes.

CONCLUSIONS

Risk communication interventions may be most productive if they include individual risk estimates in the discussion between professional and patient. Patient decisions about treatment appear more amenable to change by these interventions than attendance for screening or modification of risky behavior.

The renal medullary microcirculation

Blood flow to the renal medulla is supplied through descending vasa recta (DVR), which are derived from the efferent arterioles of juxtamedullary glomeruli. In addition to their role as conduits for blood flow, it is accepted that the vasa recta are countercurrent exchangers. That process, however, involves events which are more complicated than paracellular diffusive exchange of NaCl and urea. Urea transport in DVR is accommodated through the combined expression of endothelial and erythrocyte facilitated carriers while transport of water involves solute driven efflux across water channels. Unlike DVR, which have a continuous endothelium, ascending vasa recta (AVR) are fenestrated with a very high hydraulic conductivity. Transport of water in AVR is probably governed by transmural hydraulic and oncotic pressure gradients. The parallel arrangement of DVR in outer medullary vascular bundles coupled with their capacity for vasomotion implies a role for regulation of the regional distribution of blood flow within the medulla The importance of the latter process in the urinary concentrating mechanism and the exchange of nutrients and O2 is poorly defined. The large number of hormones and autacoids that influence DVR vasomotion, however, suggests that DVR have evolved to optimize the functions of the renal medulla.