450 Retrospective Analysis of Surgical Clerk-Ins Within the Acute Receiving Unit: A Quality Improvement Project

Introduction

Accurate patient documentation at the ARU is vital to patient safety and ensuring smooth handovers to secondary care services. Because the nature of surgical treatment requires frequent patient handovers, and this increases the risk of miscommunication, we aimed to assess the quality of surgical clerk-ins and identify areas for improvement.

Method

Emergency admissions at the Dumfries Galloway Royal Infirmary were audited, looking at documentation quality under various clerk-in sections. Data was analysed before presentation to clinical governance.

Results

When 46 patient clerk-ins were examined, venous thromboembolism (VTE) prophylaxis plans were performed in only 24% of admissions - less than 1 in 4 patients.

Comparing out-of-hours and in-hours patient documentation, much higher omission rates were identified in the out-of-hours documentation: in systemic enquiry (42 vs 100%) and family history (31% vs 66%).

Conclusions

These results brought to attention the effect of hospital admission timing on patient documentation quality, and the lack of VTE prophylaxis planning. In surgery, these plans are key to minimising risk of avoidable thromboembolic complications.

A departmental meeting was convened to stress the importance of accurate and comprehensive clerk-ins to ARU doctors. Future audits could explore the factors influencing documentation quality for out-of-hours admissions, and ways to address these issues.

A single fast radio burst localized to a massive galaxy at cosmological distance

Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 kiloparsecs from the center of a luminous galaxy at redshift 0.3214. The burst has not been observed to repeat. The properties of the burst and its host are markedly different from those of the only other accurately localized FRB source. The integrated electron column density along the line of sight closely matches models of the intergalactic medium, indicating that some FRBs are clean probes of the baryonic component of the cosmic web.

Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices

Objectives

Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs.

Methods

Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests.

Results

The method of loading was found to affect the gap stiffness strongly (by up to six times) but also the magnitude of the plate stress and the location and magnitude of strains at the bone-screw interface.

Conclusions

This study demonstrates that the method of loading is responsible for much of the difference in reported stiffness values in the literature. It also shows that previous contradictory findings, such as the influence of working length and very large differences in failure loads, can be readily explained by the choice of loading condition.

Cite this article: A. MacLeod, A. H. R. W. Simpson, P. Pankaj. Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices. Bone Joint Res 2018;7:111–120. DOI: 10.1302/2046-3758.71.BJR-2017-0074.R2.

A Regional Decision Support Scheme for Pest Risk Analysis in Southeast Asia

A key justification to support plant health regulations is the ability of quarantine services to conduct pest risk analyses (PRA). Despite the supranational nature of biological invasions and the close proximity and connectivity of Southeast Asian countries, PRAs are conducted at the national level. Furthermore, some countries have limited experience in the development of PRAs, which may result in inadequate phytosanitary responses that put their plant resources at risk to pests vectored via international trade. We review existing decision support schemes for PRAs and, following international standards for phytosanitary measures, propose new methods that adapt existing practices to suit the unique characteristics of Southeast Asia. Using a formal written expert elicitation survey, a panel of regional scientific experts was asked to identify and rate unique traits of Southeast Asia with respect to PRA. Subsequently, an expert elicitation workshop with plant protection officials was conducted to verify the potential applicability of the developed methods. Rich biodiversity, shortage of trained personnel, social vulnerability, tropical climate, agriculture-dependent economies, high rates of land-use change, and difficulties in implementing risk management options were identified as challenging Southeast Asian traits. The developed methods emphasize local Southeast Asian conditions and could help support authorities responsible for carrying out PRAs within the region. These methods could also facilitate the creation of other PRA schemes in low- and middle-income tropical countries.

Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus

The Lower to Middle Paleolithic transition (~400,000 to 200,000 years ago) is marked by technical, behavioral, and anatomical changes among hominin populations throughout Africa and Eurasia. The replacement of bifacial stone tools, such as handaxes, by tools made on flakes detached from Levallois cores documents the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier and has been argued to result from the expansion of archaic Homo sapiens out of Africa. Our data from Nor Geghi 1, Armenia, record the earliest synchronic use of bifacial and Levallois technology outside Africa and are consistent with the hypothesis that this transition occurred independently within geographically dispersed, technologically precocious hominin populations with a shared technological ancestry.

Human host determinants influencing the outcome of Trypanosoma brucei gambiense infections

Since first identified, human African trypanosomiasis (HAT) or sleeping sickness has been described as invariably fatal. Increasing data however argue that infection by Trypanosoma brucei gambiense, the causative agent of HAT, results in a wide range of outcomes in its human host and importantly that a number of subjects in endemic areas are apparently able to control infection to low levels, undetectable by the classical parasitological tests used in the field. Thus, trypanotolerance seems to occur in humans as has already been described in cattle or in the rodent experimental models of infection. This review focuses on the description of the diversity of outcomes resulting from T. b. gambiense in humans and on the host factors involved. The consequences/impacts on HAT epidemiology resulting from this diversity are also discussed with regard to implementing sustainable HAT control strategies.

Early referral strategies for management of people with markers of renal disease: a systematic review of the evidence of clinical effectiveness, cost-effectiveness and economic analysis

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition and has been described as the gradual loss of kidney function over time. Early in the disease process, people with CKD often experience no symptoms. For a long time, CKD has been an underdiagnosed condition. Even in the absence of symptoms, CKD appears to add significantly to the burden of cardiovascular disease and death and, for an important minority, can progress to kidney failure.

OBJECTIVE

To systematically review the evidence of the clinical effectiveness and cost-effectiveness of early referral strategies for management of people with markers of renal disease.

DATA SOURCES

Electronic searches of 12 major databases (such as MEDLINE, EMBASE, CINAHL, etc.) were conducted for the time period of 1990 to April 2008 to identify studies comparing early referral to other care options for people with CKD. Additional searching was performed in the NHS Economic Evaluation Database to support the cost-effectiveness literature review.

REVIEW METHODS

Two authors reviewed all titles, abstracts and full papers to select relevant literature. A Markov model was constructed to represent the natural history of CKD. The model allowed cohorts to be tracked according to estimated glomerular filtration rate (eGFR) status and the presence of other complications known to influence CKD progression and the incidence of cardiovascular events.

RESULTS

From 36 relevant natural history studies, CKD was found to be, despite marked heterogeneity between studies, a marker of increased risk of mortality, renal progression and end-stage renal disease. Mortality was generally high and increased with stage of CKD. After adjustment for comorbidities, the relative risk of mortality among those with CKD identified from the general population increased with stage. For clinical populations, the relative risk was higher. All three outcomes increased as eGFR fell. Only seven studies, and no randomised controlled trials, were identified as relevant to assessing the clinical effectiveness of early referral strategies for CKD. In the five retrospective studies constructed from cohorts starting on renal replacement therapy (RRT), mortality was reduced in the early referral group (more than 12 months prior to RRT) even as late as 5 years after initiation of RRT. Only two studies included predialysis participants. One study, in people screened for diabetic nephropathy, reported a reduction in the decline in renal function associated with early referral to nephrology specialists (eGFR decline 3.4 ml/min/1.73 m(2)) when compared with a similar group that had no access to nephrology services until dialysis was required (eGFR decline 12.0 ml/min/1.73 m(2)). The second study, among a group of veterans with two creatinine levels of at least 140 mg/dl, reported that a composite end point of death or progression was lower in the group receiving nephrology follow-up than in those receiving only primary care follow-up. The greatest effect was observed in those with stage 3 or worse disease after adjustment for comorbidities, age, race, smoking and proteinuria {stage 3: hazard ratio (HR) 0.8 [95% confidence interval (CI) 0.61 to 0.9)]; stage 4: HR 0.75 (95% CI 0.45 to 0.89)}. In the base-case analysis, all early referral strategies produced more quality-adjusted life-years (QALYs) than referral upon transit to stage 5 CKD (eGFR 15 ml/min/1.73 m(2)). Referral for everyone with an eGFR below 60 ml/min/1.73 m(2) (stage 3a CKD) generated the most QALYs and, compared with referral for stage 4 CKD (eGFR < 30 ml/min/1.73 m(2)), had an incremental cost-effectiveness ratio of approximately 3806 pounds per QALY.

LIMITATIONS

Because of a lack of data on the natural history of CKD in individuals without diabetes, and a lack of evidence on the costs and effects of early referral, the Markov model relied on many assumptions. The findings were particularly sensitive to changes in eGFR decline rates and the relative effect of early referral on CKD progression and cardiovascular events; the latter parameter being derived from a single non-randomised study.

CONCLUSIONS

Despite substantial focus on the early identification and proactive management of CKD in the last few years, we have identified significant evidence gaps about how best to manage people with CKD. There was some evidence to suggest that the care of people with CKD could be improved and, because these people are at risk from both renal and cardiovascular outcomes, strategies to improve the management of people with CKD have the potential to offer an efficient use of health service resources. Given the number of people now being recognised as having markers of kidney impairment, there is an urgent need for further research to support service change.

Integrating drivers influencing the detection of plant pests carried in the international cut flower trade

This paper analyses the cut flower market as an example of an invasion pathway along which species of non-indigenous plant pests can travel to reach new areas. The paper examines the probability of pest detection by assessing information on pest detection and detection effort associated with the import of cut flowers. We test the link between the probability of plant pest arrivals, as a precursor to potential invasion, and volume of traded flowers using count data regression models. The analysis is applied to the UK import of specific genera of cut flowers from Kenya between 1996 and 2004. There is a link between pest detection and the Genus of cut flower imported. Hence, pest detection efforts should focus on identifying and targeting those imported plants with a high risk of carrying pest species. For most of the plants studied, efforts allocated to inspection have a significant influence on the probability of pest detection. However, by better targeting inspection efforts, it is shown that plant inspection effort could be reduced without increasing the risk of pest entry. Similarly, for most of the plants analysed, an increase in volume traded will not necessarily lead to an increase in the number of pests entering the UK. For some species, such as Carthamus and Veronica, the volume of flowers traded has a significant and positive impact on the likelihood of pest detection. We conclude that analysis at the rank of plant Genus is important both to understand the effectiveness of plant pest detection efforts and consequently to manage the risk of introduction of non-indigenous species.

A nurse-/pharmacy-led capecitabine clinic for colorectal cancer: Results of a prospective audit and retrospective survey of patient experiences

Oral chemotherapy agents provide patients with choice and home-based therapy but demand greater emphasis on patient support and education to minimise toxicities. To meet this demand, a nurse-/pharmacy-led clinic was established at the Beatson Oncology Centre in 2003 for the provision of oral capecitabine to metastatic colorectal cancer patients to provide a controlled and supportive environment. We conducted a prospective audit of 52 patients attending the clinic from March 2003 to June 2004 and a retrospective survey of patient experiences to assess clinic effectiveness. Of 52 patients, 79% completed at least 3 cycles of treatment (mean 3.5). Capecitabine was well tolerated. The dose was reduced on at least one occasion in 15 (29%) patients and 17 (30%) patients experienced at least one delay. Patient satisfaction, indicated by questionnaire responses (n=27), was high. Most patients (> or =85%) thought that the service provision was useful and well organised. The results indicate that a nurse-/pharmacy-led clinic for the provision of home-based oral capecitabine is safe, effective and acceptable to most patients. The success of this clinic can provide a model for use in other centres and in other types of cancer, such as breast cancer, where oral chemotherapy is a treatment option.

Human infectivity trait in Trypanosoma brucei: stability, heritability and relationship to sra expression

Some Trypanosoma brucei lines infect humans whereas others do not because the parasites are lysed by human serum. We have developed a robust, quantitative in vitro assay based on differential uptake of fluorescent dyes by live and dead trypanosomes to quantify the extent and kinetics of killing by human serum. This method has been used to discriminate between 3 classes of human serum resistance; sensitive, resistant and intermediate. TREU 927/4, the parasite used for the T. brucei genome project, is intermediate. The phenotype is expressed in both bloodstream and metacyclic forms, is stably expressed during chronic infections and on cyclical transmission through tsetse flies. Trypanosomes of intermediate phenotype are distinguished from sensitive populations of cells by the slower rate of lysis and by the potential to become fully resistant to killing by human serum as a result of selection or long-term serial passaging in mice, and to pass on full resistance phenotype to its progeny in a genetic cross. The sra gene has been shown previously to determine human serum resistance in T. brucei but screening for the presence and expression of this gene indicated that it is not responsible for the human serum resistance phenotype in the trypanosome lines that we have examined, indicating that an alternative mechanism for HSR exists in these stocks. Examination of the inheritance of the phenotype in F1 hybrids for both bloodstream and metacyclic stages from 2 genetic crosses demonstrated that the phenotype is co-inherited in both life-cycle stages in a manner consistent with being a Mendelian trait, determined by only one or a few genes.

Randomized controlled trial of brief cognitive behaviour therapy versus treatment as usual in recurrent deliberate self-harm: the POPMACT study

BACKGROUND

We carried out a large randomized trial of a brief form of cognitive therapy, manual-assisted cognitive behaviour therapy (MACT) versus treatment as usual (TAU) for deliberate self-harm.

METHOD

Patients presenting with recurrent deliberate self-harm in five centres were randomized to either MACT or (TAU) and followed up over 1 year. MACT patients received a booklet based on cognitive behaviour therapy (CBT) principles and were offered up to five plus two booster sessions of CBT from a therapist in the first 3 months of the study. Ratings of parasuicide risk, anxiety, depression, social functioning and global function, positive and negative thinking, and quality of life were measured at baseline and after 6 and 12 months.

RESULTS

Four hundred and eighty patients were randomized. Sixty per cent of the MACT group had both the booklet and CBT sessions. There were seven suicides, five in the TAU group. The main outcome measure, the proportion of those repeating deliberate self-harm in the 12 months of the study, showed no significant difference between those treated with MACT (39%) and treatment as usual (46%) (OR 0.78, 95% CI 0.53 to 1.14, P=0.20).

CONCLUSION

Brief cognitive behaviour therapy is of limited efficacy in reducing self-harm repetition, but the findings taken in conjunctin with the economic evaluation (Byford et al. 2003) indicate superiority of MACT over TAU in terms of cost and effectiveness combined.

Continuous ambulatory peritoneal dialysis (CAPD) versus hospital or home haemodialysis for end-stage renal disease in adults

BACKGROUND

Renal replacement therapy (RRT) with dialysis and transplantation is the only means of sustaining life for patients with end-stage renal disease (ESRD). Although transplantation is the treatment of choice, the number of donor kidneys are limited and transplants may fail. Hence many patients require long-term or even life-long dialysis. Continuous ambulatory peritoneal dialysis (CAPD) is an alternative to hospital or home haemodialysis for patients with ESRD.

OBJECTIVES

To assess the benefits and harms of CAPD versus hospital or home haemodialysis for adults with ESRD.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (Cochrane Library, Issue 2, 2002), the Cochrane Renal Group's Specialised Register (May 2002), MEDLINE (1966 - May 2002), EMBASE (1980 - May 2002), BIOSIS, CINHAL, SIGLE and NRR without language restriction. Reference lists of retrieved articles and conference proceedings were searched and known investigators and biomedical companies were contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing CAPD to hospital or home haemodialysis for adults with ESRD were to be included.

DATA COLLECTION AND ANALYSIS

Two reviewers were to independently assess the methodological quality of studies. Data was to be abstracted from included studies onto a standard form by one reviewer and checked by another. Statistical analyses were to be performed using the random effects model and the results to be expressed as relative risk (RR) with 95% confidence intervals (95% CI).

MAIN RESULTS

Despite extensive searching, no RCTs or quasi-RCTs were identified.

REVIEWER'S CONCLUSIONS

Data are not available to allow conclusions to be drawn about the relative effectiveness of CAPD compared with hospital or home haemodialysis for adults with ESRD. Efforts should be made to start and complete adequately powered RCTs, which compare the different dialysis modalities.

Engineering and cell attachment properties of human fibronectin-fibrinogen scaffolds for use in tissue engineered blood vessels

Tissue engineered constructs reported to date have been prepared primarily from poly(glycolic) acid or collagen scaffolds onto which cells are grown and matured. In this paper we report experimental data to demonstrate the use of a natural, human protein, as a tubular scaffold for vascular grafting. Using a manual and a scalable dip-coating technique we prepared fibronectin-based tubes up to 12 cm in length and up to 3 mm in diameter. The tubes were flexible and their mechanical properties, measured in terms of tensile strength and burst pressure as a function of humidity, demonstrated their suitability as scaffolds for use in vascular grafting, e.g. coronary artery by pass grafting. In vitro tests involved the attachment of endothelial cells pumped under laminar flow conditions through the tube lumen and the adherence of smooth muscle cells on the outer surface of the tubes. These tests, carried out in multiwells, showed that the scaffolds had excellent cell attachment and guidance characteristics.

Benchmarking best practice for external ventricular drainage

Sharing of best practice and use of all available evidence is important in developing effective clinical guidelines for nursing practice. This can be achieved through benchmarking. Sharing of good practice and achieving consensus guidelines can avoid repetition of effort by nurses engaged in similar fields of practice. The Pan London Neuroscience Practice Development Forum was established in 1998 to share best practice within the field of neuroscience nursing across London. The Pan London Forum has now achieved consensus and developed evidence-based clinical guidelines for the management of external ventricular drainage. Within the scope of this article, the principles of external ventricular drainage will be highlighted, before identifying the evidence base for nursing management of patients. Approaches for troubleshooting common problems will also be discussed and the benchmarked clinical guidelines will be presented.

Frequency of administration of recombinant human erythropoietin for anaemia of end-stage renal disease in dialysis patients

BACKGROUND

Although the benefits of recombinant human erythropoietin (rHu EPO) administration in dialysis patients have been demonstrated the optimal frequency regimen has not as yet been established. Treatment with rHu EPO is expensive, there is therefore a need for optimising the efficiency of its administration.

OBJECTIVES

The objectives of this review were to assess the effects of different frequency regimens of rHu EPO administration in dialysis patients in terms of i) effectiveness (correction of anaemia, quality of life and freedom from adverse events) ii) efficiency (optimal resource use) of different rHu EPO dose regimen policies.

SEARCH STRATEGY

We searched MEDLINE (1980 to May Week 3 2001), EMBASE (1984 to Week 24 2001), BIOSIS (1985 to January 1997), CINAHL (1982 to October 1997), The Cochrane Library (Issue 1, 1997), CHEMABS (1984 to November 1996), SIGLE (1980 to June 1996), CRIB (10th edition, 1995), UK NRR (14th consolidation, September 1996), RSC ( 1980 to February 1997), HealthSTAR (1995 to October 1997), IBSS (1984 to July 1997), NEED (July 1997) and reference lists of relevant articles. We contacted biomedical companies and investigators in the field and we hand searched Kidney International (including all supplements but excluding all conference proceedings except for 1994) July 1983 to May 1997 inclusive. The Internet was also searched on: August 1997. We had also identified some studies from a previous broad search for all randomised controlled trials (RCTs) relevant to the management of end-stage renal disease. Date of the most recent search: June 2001.

SELECTION CRITERIA

All randomised or quasi randomised controlled trials comparing different frequencies of rHu EPO administration in dialysis patients. Subgroup analyses were performed comparing haemodialysis and CAPD patients and also subcutaneous and intravenous administration.

DATA COLLECTION AND ANALYSIS

Only published data were used. Data were abstracted by a single investigator on to a standard form. The data abstracted were relevant to the predetermined outcome measures: measures of correction of anaemia, rHu EPO dose, quality of life measures, adverse events, number of withdrawals from study, mortality. Where appropriate, a summary relative risk (RR) was calculated for dichotomous data and a weighted mean difference (WMD) or standardised mean difference (SMD) for continuous data.

MAIN RESULTS

Eight studies met our inclusion criteria. When once a week administration was compared with twice weekly there was no significant difference in the ability to maintain the target haemoglobin (RR 1.00, 95% CI 0.42 to 2.40). Mean haemoglobin after twelve weeks of therapy was not different between the two groups (WMD -0.21g/dl, 95% CI -0.98 to 0.56). No difference was found in mean haemoglobin or haematocrit at the end of any studies which compared once with thrice weekly administration of rHu EPO (SMD -0.31, 95% CI -0.67 to 0.06). A single study which compared once with more that thrice weekly administration showed no significant difference in mean haemoglobin at the end of the maintenance phase (mean difference -0.2g/dl, 95% CI -0.65 to 0.25). The dosage of erythropoietin required by those on haemodialysis receiving rHu EPO once weekly was just significantly more (WMD 12.0 U/kg, 95% CI 0.24 to 23.76) than those receiving it twice weekly but the confidence interval is wide. No such difference was found for CAPD patients nor when the results were combined (WMD 5.15 U/kg, 95% CI -3.74 to 14.05). The result was not significant when comparing once weekly with thrice weekly administration (WMD 10.00 U/kg, 95% CI -80.87 to 100.87). There was no difference in the frequency of adverse events between any of the groups studies.

REVIEWER'S CONCLUSIONS

There is no significant difference between once weekly versus thrice weekly subcutaneous administration of rHu EPO. Once weekly administration of rHu EPO would require an additional 12U/kg/week for patients on haemodialysis, however this is based on one very small study. The cost of this additional hRu EPO nee, however this is based on one very small study. The cost of this additional hRu EPO needs to assessed, in particular with regard to patient preference and compliance.

Correction for MacLeod et al. , The population genetics of Trypanosoma brucei and the origin of human infectivity

Correction for ‘The population genetics of Trypanosoma brucei and the origin of human infectivity’ by A. MacLeod, A. Tait and M. R. Turner (Phil. Trans. R. Soc. Lond. B 356 , 1035–1044. (doi: 10.1098/rstb.2001.0892 )).

Figure 1 contained some incorrect symbols. The amended figure and its caption are reproduced below.

The detection of geographical substructuring of Trypanosoma brucei populations by the analysis of minisatellite polymorphisms

Analysis of natural populations of Trypanosoma brucei has shown that there is linkage disequilibrium between alleles at pairs of loci in isolates taken from the field. This disequilibrium can occur as a result of a low frequency of genetic exchange, the masking of frequent genetic exchange by the rapid expansion of a few genotypes or by the treatment of 2 (or more) genetically isolated populations as a single population. We have analysed stocks from 2 geographically separate locations using 3 minisatellite markers to determine the frequencies of the alleles in each area and the frequency and nature of the multilocus genotypes. The results show that many alleles and multilocus genotypes are unique to each geographical location, supporting the conclusion that these populations are genetically isolated with limited or no gene flow between them. This geographical substructuring needs to be taken into account in considering the origins of the linkage disequilibrium in a number of populations.

Future-directed thinking in eating disorders

OBJECTIVES

The aim of the study was to examine future-directed thinking in individuals with eating disorders, given the possible role of such cognitions in the maintenance of anorexia nervosa and bulimia nervosa.

METHOD

Twenty-six anorexics, 18 bulimics and 34 female controls were interviewed using the 'Future Thinking Task', assessing quantitative and qualitative aspects of positive and negative anticipated events.

RESULTS

Patients with anorexia nervosa had similar levels of positive future-oriented cognitions and significantly more negative future-oriented cognitions than controls. The most common positive themes in this group concerned the social/interpersonal and leisure/pleasure domains. The negative theme most commonly mentioned by anorexics was that of their own health, followed by the social/interpersonal domain, whereas controls were most preoccupied with achievement/failure and a broad range of other issues. Bulimics had significantly fewer positive future-oriented cognitions and significantly more negative future-oriented cognitions than controls, most commonly concerning the patient's own health.

CONCLUSION

In anorexia nervosa, anticipated positive future outcomes may to some extent help to maintain the disorder; however, these patients are also highly preoccupied with the possibility of negative future outcomes, i.e. a failure of recovery. Bulimia nervosa sufferers are relatively hopeless about their future. The clinical implications of these findings are discussed.

The population genetics of Trypanosoma brucei and the origin of human infectivity

The African trypanosome, Trypanosoma brucei, is a zoonotic parasite transmitted by tsetse flies. Two of the three subspecies, T. brucei gambiense and T.b. rhodesiense, cause sleeping sickness in humans whereas the third subspecies, T.b. brucei, is not infective to humans. We propose that the key to understanding genetic relationships within this species is the analysis of gene flow to determine the importance of genetic exchange within populations and the relatedness of populations. T.brucei parasites undergo genetic exchange when present in infections of mixed genotypes in tsetse flies in the laboratory, although this is not an obligatory process. Infections of mixed genotype are surprisingly common in field isolates from tsetse flies such that there is opportunity for genetic exchange to occur. Population genetic analyses, taking into account geographical and host species of origin, show that genetic exchange occurs sufficiently frequently in the field to be an important determinant of genetic diversity, except where particular clones have acquired the ability to infect humans. Thus, T. brucei populations have an 'epidemic' genetic structure, but the better-characterized human-infective populations have a 'clonal' structure. Remarkably, the ability to infect humans appears to have arisen on multiple occasions in different geographical locations in sub-Saharan Africa. Our data indicate that the classical subspecies terminology for T. brucei is genetically inappropriate. It is an implicit assumption in most infectious disease biology that when a zoonotic pathogen acquires the capability to infect humans, it does so once and then spreads through the human population from that single-source event. For at least one major pathogen in tropical medicine, T. brucei, this assumption is invalid.

Evidence for multiple origins of human infectivity in Trypanosoma brucei revealed by minisatellite variant repeat mapping

In recent years a wide variety of biochemical and molecular typing systems has been employed in the study of parasite diversity aimed at investigating the level of genetic diversity and delineating the relationship between different species and subspecies. However, such methods have failed to differentiate between two of the classically defined subspecies of the protozoan parasite Trypanosoma brucei: the human infective, T. b. rhodesiense, which causes African sleeping sickness, and the non-human infective T. b. brucei. This has led to the hypothesis that T. b. rhodesiense is a host range variant of T. b. brucei. In this paper we test this hypothesis by examining highly polymorphic tandemly repeated regions of the trypanosome genome, i.e., minisatellite loci. We have employed the technique of minisatellite variant repeat mapping by PCR (MVR-PCR), which determines the distribution of variant repeat units along the tandem array of one minisatellite, MS42. The maps generated by this technique not only allow unequivocal allele identification but also contain within them cladistic information which we used to determine the possible genetic relationship between the different subspecies of T. brucei. Our findings revealed that human infective (T. b. rhodesiense) isolates from Uganda are more closely related to the local non-human infective isolates (T. b. brucei) than they are to other human infective stocks from different regions, suggesting that human infectivity has originated independently in these different geographical regions. This would infer that the separate classification of all human infective stocks from East Africa into the subspecies T. b. rhodesiense is genetically inappropriate and it would be better to consider geographically separate populations as host range variants of T. brucei brucei or perhaps as a series of different subspecies. Based on these data, it is clear that MVR mapping is a very useful tool for the analysis of zoonotic eukaryotic pathogens where delineation of the origins of outbreaks of disease and definition of human infective strains are key questions.

Comparison of cellulose, modified cellulose and synthetic membranes in the haemodialysis of patients with end-stage renal disease

BACKGROUND

When the kidney fails the blood borne metabolites of protein breakdown and water cannot be excreted. The principle of haemodialysis is that such substances can be removed when blood is passed over a semipermeable membrane. Natural membrane materials can be used including cellulose or modified cellulose, more recently various synthetic membranes have been developed. Synthetic membranes are regarded as being more "biocompatible" in that they incite less of an immune response than cellulose-based membranes.

OBJECTIVES

To assess the effects of different haemodialysis membrane material in patients with end-stage renal disease (ESRD).

SEARCH STRATEGY

We searched Medline (1966 to December 2000), Embase (1981 to November 2000), PreMedline (29 November 2000), HealthStar (1975 to December 2000), Cinahl (1982 to October 2000), The Cochrane Controlled Trials Register (Issue 1, 1996), Biosis (1989 to June 1995), Sigle (1980 to June 1996), Crib (10th edition, 1995), UK National Research Register (September 1996), and reference lists of relevant articles. We contacted biomedical companies, investigators and we hand searched Kidney International (1980 to 1997). Date of the most recent searches: November 2000.

SELECTION CRITERIA

All randomised or quasi-randomised clinical trials comparing different haemodialysis membrane material in patients with ESRD.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the methodological quality of studies. Data was abstracted from included studies onto a standard form by one reviewer and checked by another.

MAIN RESULTS

Twenty seven studies met our inclusion criteria and where possible data from these were summated by meta-analyses (Peto's odds ratio (OR) and weighted mean difference (WMD) with 95% confidence intervals (CI)). Twenty two outcome measures were sought in 10 broad areas. For two (number of episodes of significant infection per year and quality of life) no data were available. For the comparison of cellulose with synthetic membranes, data for 12/20 outcome measures were available in only a single trial. For modified cellulose and synthetic membranes, data for three outcome measures were available in one trial only and for 12 of the outcomes no data were found, crossover studies were analysed separately and studies which randomised by patient yet analysed by dialysis sessions adjusted for clustering. Pre-dialysis beta2 microglobulin concentrations were significantly lower at the end of the studies in patients treated with synthetic membranes (WMD - 14.5; 95% CI -17.4 to -11.6). One crossover study showed a lowering of beta2 microglobulin when low flux synthetic membranes were used. When analysed for a change in beta2 microglobulin across a trial a fall was only noted when high flux membranes were used. In one very small study the incidence of amyloid was less in patients who were dialysed for six years with high flux synthetic membranes (OR 0.05; 95% CI 0.01 to 0.18). In the single study which measured triglyceride values there was a significant difference in favour of the synthetic (high flux) membrane (WMD -0.66; 95% CI -1.18 to -0.14). Serum albumin was higher in patients treated with synthetic membranes (both low and high flux) although this just bordered statistical significance (WMD -0.09; 95% CI -0.18 to 0.00). Dialysis adequacy measured by Kt/V was marginally higher when cellulose membranes were used (WMD 0.10; 95% CI 0.04 to 0.16). There was no significant difference between these membranes for any of the other clinical outcomes measures but confidence intervals were generally wide. No differences were found between modified cellulose and synthetic membranes although many fewer trials were carried out for this comparison.

REVIEWER'S CONCLUSIONS

For clinical practice This systematic literature review has generated no evidence of benefit when synthetic membranes were used compared with cellulose/modified cellulose membranes in terms of reduced mortality nor reduction in dialysis related adverse symptoms. Despite the relatively large number of RCTs undertaken in this area none of the included studies reported any measures of quality of life. End-of-study beta2 microglobulin values, and possibly the development of amyloid disease, were less in patients treated with synthetic membranes compared with cellulose membranes. Plasma triglyceride values were also lower with synthetic membranes in the single study that measured this outcome. Differences in these outcomes may have reflected the high flux of the synthetic membrane. Serum albumin was higher when synthetic membranes of both high and low flux were used. Kt/V and urea reduction ratio were higher when cellulose or modified cellulose membranes were used in the few studies that measured these outcomes. We are hesitant to recommend the universal use of synthetic membranes for haemodialysis in patients with ESRD because of; the small number of trials (particularly for modified cellulose membranes, most with low patient numbers), the heterogeneity of many of the trials compared, the variations in membrane flux, the differences in exclusion criteria, particularly relating to comorbidity and the relative lack of patient-centred outcomes studied. Such evidence as we have favours synthetic membranes but even if we assume extra benefit it may be at considerable cost, particularly if high flux synthetic membranes were to be used. For further research A further systematic review of RCTs comparing high and low flux haemodialysis membranes, subgrouped according to membrane composition (cellulose, modified cellulose, synthetic) and reporting clinical outcomes of major importance to patients needs to be undertaken. Further pragmatic RCTs are required to compare the different dialysis membranes available. We recommend that they: - Take into account other properties including flux as well as the material from which the membrane is made and test modified cellulose membranes as well as standard ones. - Record an agreed minimum dataset on primary outcomes of major importance to patients. - Explicitly record whether symptoms are patient- or staff-reported recognising that generally patient reporting will be more appropriate for evaluating effectiveness but staff reported data may be necessary for calculating the cost of treating complications. - Be multi-centre (and possibly multinational) to have sufficient patients to complete the study to allow for a considerable number of withdrawals and dropouts. - Have sufficient length of follow up to draw conclusions for important clinical outcome measures and continue to follow patients who have renal transplants. - Include older patients and those with comorbid illnesses and take into account age and comorbidity when assessing outcomes (possibly by stratification at trial entry). - Carry out, in parallel, an economic evaluation of the different policies being compared in the trial.

Double bag or Y-set versus standard transfer systems for continuous ambulatory peritoneal dialysis in end-stage renal disease

BACKGROUND

Peritonitis is the most frequent serious complication of continuous ambulatory peritoneal dialysis (CAPD). It has a major influence on the number of patients switching from CAPD to haemodialysis and has probably restricted the wider acceptance and uptake of CAPD as an alternative mode of dialysis.

OBJECTIVES

This systematic review sought to determine if modifications of the transfer set (Y-set or double bag systems) used in CAPD exchanges are associated with a reduction in peritonitis and an improvement in other relevant outcomes.

SEARCH STRATEGY

A broad search strategy was employed which attempted to identify all RCTs or quasi-RCTs relevant to the management of end-stage renal disease (ESRD). Five electronic databases were searched (Medline 1966-1999, EMBASE 1984-1999, CINAHL 1982-1996, BIOSIS 1985-1996 and the Cochrane Library), authors of included studies and relevant biomedical companies were contacted, reference lists of identified RCTs and relevant narrative reviews were screened and Kidney International 1980-1997 was hand searched.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing double bag, Y-set and standard CAPD exchange systems in patients with ESRD.

DATA COLLECTION AND ANALYSIS

Data were abstracted by a single investigator onto a standard form and subsequently entered into Review Manager 4.0.4. Odds Ratio (OR) for dichotomous data and a (Weighted) Mean Difference (WMD) for continuous data were calculated with 95% confidence intervals (95% CI).

MAIN RESULTS

Twelve eligible trials with a total of 991 randomised patients were identified. In trials comparing either the Y-set or double bag systems with the standard systems significantly fewer patients (OR 0.33, 95% CI 0.24 to 0.46) experienced peritonitis and the number of patient-months on CAPD per episode of peritonitis were consistently greater. When the double bag systems were compared with the Y-set systems significantly fewer patients experienced peritonitis (OR 0.44, 95% CI 0.27 to 0.71) and the numbers of patient-months on CAPD/ episode of peritonitis were also greater.

REVIEWER'S CONCLUSIONS

Double bag systems should be the preferred exchange systems in CAPD.

Recombinant human erythropoietin for chronic renal failure anaemia in pre-dialysis patients

BACKGROUND

Treatment with recombinant human erythropoietin (rHu EPO) in dialysis patients has been shown to be highly effective in terms of correcting anaemia and improving quality of life. There is debate concerning the benefits of rHu EPO use in pre-dialysis patients. There is a concern that rHu EPO may accelerate the deterioration in renal function, however the opposing view is that if rHu EPO is as effective in pre-dialysis patients that by improving the patients sense of well-being the onset of dialysis could be delayed.

OBJECTIVES

To assess the effects of rHu EPO use in pre-dialysis patients with renal anaemia.

SEARCH STRATEGY

We searched MEDLINE (1980 to May Week 3 2001), EMBASE (1984 to Week 24 2001), BIOSIS (1985 to January 1997), CINAHL (1982 to October 1997), The Cochrane Library (Issue 1, 1997), CHEMABS (1984 to November 1996), SIGLE (1980 to June 1996), CRIB (10th edition, 1995), UK NRR (14TH consolidation, September 1996), RSC ( 1980 to February 1997), HealthSTAR (1995 to October 1997), IBSS (1984 to July 1997), NEED (July 1997) and reference lists of relevant articles. We contacted biomedical companies and investigators in the field and we hand searched Kidney International (including all supplements but excluding all conference proceedings except for 1994) July 1983 to May 1997 inclusive. The internet was also searched on: August 1997. We had also identified some studies from a previous broad search for all randomised controlled trials (RCTs) relevant to the management of end-stage renal disease. Date of the most recent search: June 2001.

SELECTION CRITERIA

RCTs or quasi-RCTs comparing the use of rHu EPO with no rHu EPO or placebo in pre-dialysis patients.

DATA COLLECTION AND ANALYSIS

Only published data were used. Data were abstracted by a single investigator onto a standard form. A sample of the data abstracted was double-checked by another reviewer. The data abstracted were relevant to the predetermined outcome measures. Some authors were contacted to clarify how patients were allocated to groups. All authors from included studies were contacted for missing information.

MAIN RESULTS

Twelve studies with a total of 232 participants met the inclusion criteria and where possible data from these were summated by meta-analyses (Peto's Odds Ratio (OR) and Weighted Mean Difference (WMD)). The majority of the trials included small numbers and were of short duration (8-10 weeks) with the exception of three trials. There was a marked improvement in haemoglobin (mean difference 2.3g/dL, 95% CI 1.37 to 3.23) and haematocrit (WMD 9.92%, 95% CI 8.78 to 11.05) with the treatment and a decrease in the number of patients requiring blood transfusion (OR 0.25, 95% CI 0.09 to 0.69). The data from all studies which reported quality of life or exercise capacity demonstrated an improvement in the rHu EPO group. None of the measures of progression of renal disease (when a summary statistic was calculated) demonstrated a statistically significant difference. Though the requirement for antihypertensive treatment appears to be increased by rHu EPO (OR 1.84, 95% CI 1.02 to 3.32), there was no other statistically significant increase in adverse events. Based on the limited current evidence, decisions therefore have to be made on whether the putative benefits in terms of quality of life identified in the review are worth the extra costs of pre-dialysis rHu EPO.

REVIEWER'S CONCLUSIONS

This review has shown that treatment with rHu EPO in pre-dialysis patients corrects anaemia and avoids the requirement for blood transfusions. There are also improvements in quality of life and exercise capacity. There may be increased hypertension. Most of the trials were not of sufficient duration to assess the effects of rHu EPO on progression of renal disease. In the long term, questions still remain about whether pre-dialysis rHu EPO either speeds up or delays the onset of dialysis. Thus there is insufficient evidence on the total costs and benefits of treating pre-dialysis patients with rHu EPO.

Minisatellite marker analysis of Trypanosoma brucei: reconciliation of clonal, panmictic, and epidemic population genetic structures

The African trypanosome, Trypanosoma brucei, has been shown to undergo genetic exchange in the laboratory, but controversy exists as to the role of genetic exchange in natural populations. Much of the analysis to date has been derived from isoenzyme or randomly amplified polymorphic DNA data with parasite material from a range of hosts and geographical locations. These markers fail to distinguish between the human infective (T. b. rhodesiense) and nonhuman infective (T. b. brucei) "subspecies" so that parasites derived from hosts other than humans potentially contain both subspecies. To overcome some of the inherent problems with the use of such markers and diverse populations, we have analyzed a well-defined population from a discrete geographical location (Busoga, Uganda) using three recently described minisatellite markers. The parasites were primarily isolated from humans and cattle with the latter isolates further characterized by their ability to resist lysis by human serum (equivalent to human infectivity). The minisatellite markers show high levels of polymorphism, and from the data obtained we conclude that T. b. rhodesiense is genetically isolated from T. b. brucei and can be unambiguously identified by its multilocus genotype. Analysis of the genotype frequencies in the separated T. b. brucei and T. b. rhodesiense populations shows the former has an epidemic population structure whereas the latter is clonal. This finding suggests that the strong linkage disequilibrium observed in previous analyses, where human and nonhuman infective trypanosomes were not distinguished, results from the treatment of two genetically isolated populations as a single population.

Childhood trauma, dissociation and self-harming behaviour: a pilot study

OBJECTIVE

Childhood trauma is known to be an important antecedent in those who engage in deliberate self-harm (DSH). We aimed to explore the mediating mechanisms between childhood trauma and subsequent DSH in a sample of women detained in a high secure setting.

METHOD

From a previous incidence study into DSH, we subdivided a group of 50 women as follows: non-harmers (N = 13), infrequent harmers (N = 22) and frequent harmers (N = 15). These three groups were then compared on several measures believed to be associated with DSH.

RESULTS

The frequency of DSH was related to low self-esteem, increased dissociation, anger (both inwardly and outwardly directed), impulsivity, and a history of sexual and physical abuse. When these variables were entered into a path analytic model exploring the relationship between childhood trauma and subsequent DSH, two paths emerged: one major path which linked childhood sexual abuse to DSH via increased dissociation and another, more minor association, linking childhood sexual abuse via reduced self-esteem.

CONCLUSION

This study shows a strong association between high levels of dissociation and an increased frequency of self-harming behaviour. This association is theoretically plausible and has therapeutic implications.

Evidence-based medicine and health economics: a case study of end stage renal disease

This paper explores the potential for use of an economic evaluation framework alongside systematic reviews. Clinical issues in dialysis therapy for end stage renal disease are used as case studies. The effectiveness data required were obtained from a systematic review of randomized controlled trials. Resource use and cost data were obtained from three sources; the identified randomized controlled trials, a separate review of observational studies and primary data collection. The results of the case studies show that, although simple economic evaluations were possible, issues arose, such as how transferable results are between settings and how appropriate it is to focus on the average patient. The interface between economic evaluation and systematic reviews needs to be further developed in order to ensure that the best available evidence can be used to inform future policy and research.