A systematic review and economic model of switching from non-glycopeptide to glycopeptide antibiotic prophylaxis for surgery.

OBJECTIVES: To determine whether there is a level of methicillin-resistant Staphylococcus aureus (MRSA) prevalence at which a switch from non-glycopeptide to glycopeptide antibiotics for routine prophylaxis is indicated in surgical environments with a high risk of MRSA infection. DATA SOURCES: Major electronic databases were searched up to September 2005. REVIEW METHODS: The effectiveness review included controlled clinical trials comparing a glycopeptide with an alternative antibiotic regimen that reported effectiveness and/or adverse events. Controlled observational studies were also included for adverse events. The cost-effectiveness review included economic evaluations comparing glycopeptide prophylaxis with any alternative comparator. Study validity was assessed using standard checklists. The supplementary economic reviews assessed evaluations of non-glycopeptide antibiotic prophylaxis; evaluations where antibiotic resistance is a problem; methods of modelling resistance in infectious diseases; and developing a conceptual framework. An indicative decision analytic model was developed to compare vancomycin with a cephalosporin and with a combination of vancomycin and cephalosporin, using hip arthroplasty as an exemplar. Available data on, for example, surgical site infection (SSI) rates, MRSA rates, effectiveness of the antibiotics, were incorporated into the model. Costs were estimated from the perspective of the NHS. RESULTS: The effectiveness review included 16 randomised controlled trials, with a further three studies included for adverse events only. There was no evidence that glycopeptides were more effective than non-glycopeptides in preventing SSIs. Most of the trials did not report either the baseline prevalence of MRSA at the participating surgical units or MRSA infections as an outcome. The cost-effectiveness review included five economic evaluations of glycopeptide prophylaxis. Only one study incorporated health-related quality of life and undertook a cost-utility analysis. None of the studies was undertaken in the UK and none explicitly modelled antibiotic resistance. The supplementary reviews provided few insights into how to assess cost-effectiveness in the context of resistance. No studies modelled cost-effectiveness alongside epidemiological models of resistance. There was little information regarding the impact of surgical infections on costs post-discharge and patient quality of life. The lack of available clinical evidence limited the development of the cost-effectiveness model and meant that the modelling could only be indicative in nature. The model can be used to show the threshold baseline risk at which the use of vancomycin as prophylaxis might be cost-effective (the model did not include teicoplanin). The indicative model suggests that the baseline risk of MRSA can be fairly modest at below the national average and it would still appear cost-effective to use glycopeptide prophylaxis. The model indicates that the use of glycopeptides as a form of prophylaxis in addition to a treatment for MRSA infections is unlikely to decrease the total usage and hence reduce the risk of future problems with glycopeptide-resistant bacteria. CONCLUSIONS: There is insufficient evidence to determine whether there is a threshold prevalence of MRSA at which switching from non-glycopeptide to glycopeptide antibiotic prophylaxis might be clinically effective and cost-effective. Future research needs to address the complexities of decision-making relating to the prevention of MRSA and infection control in general. Research including evidence synthesis and decision modelling comparing a full range of interventions for infection control, which extends to other infections, not just MRSA, is needed. A long-term research programme to predict the pattern of drug resistance and its implications for future costs and health is also needed.

A systematic review of duplex ultrasound, magnetic resonance angiography and computed tomography angiography for the diagnosis and assessment of symptomatic, lower limb peripheral arterial disease.

OBJECTIVES: To determine the diagnostic accuracy and cost-effectiveness of duplex ultrasound (DUS), magnetic resonance angiography (MRA), and computed tomography angiography (CTA), as alternatives to contrast angiography (CA), for the assessment of lower limb peripheral arterial disease (PAD). DATA SOURCES: Ten electronic databases were searched in April 2004, with an update in May 2005. Six key journals and bibliographies of included studies were also searched and experts in the field were consulted. REVIEW METHODS: Data extraction and quality assessment were performed in duplicate. Data were analysed according to test type and diagnostic threshold. For the economic analysis, a decision tree was developed and a probabilistic sensitivity analysis performed to incorporate statistical uncertainty into the cost-effectiveness analysis. RESULTS: A total of 113 studies met the inclusion criteria (including six economic evaluations). For the detection of stenosis greater than 50% in the whole leg, contrast-enhanced (CE) MRA (14 studies) had the highest diagnostic accuracy, with sensitivity ranging from 92 to 99.5% and specificity from 64 to 99%. Two-dimensional (2D) time-of-flight (TOF) MRA (11 studies) was less accurate, with sensitivity ranging from 79 to 94% and specificity from 74 to 92%. 2D phase-contrast (PC) MRA (one study) had a sensitivity of 98% and specificity of 74%. CTA (seven studies) also appeared slightly inferior to CE MRA, with a sensitivity ranging from 89 to 99% and specificity from 83 to 97%, but better than DUS (28 studies), which had a sensitivity ranging from 80 to 98% and specificity from 89 to 99%. There was some indication that CE MRA and DUS were more accurate for detecting stenoses/occlusions above the knee than below the knee or in the pedal artery. The four studies of patient attitudes strongly suggested that patients preferred CE MRA to CA. CA was considered the most uncomfortable test, followed by CE MRA, with CTA being the least uncomfortable. Half of the patients (from a sample who did not suffer from claustrophobia and had no metallic implants) expressed no preference between undergoing TOF MRA or DUS; most of those who did express a preference favoured TOF MRA. In the 55 studies identified for adverse events, MRA was associated with the highest reported proportion. However, the most severe adverse events were more common in patients undergoing CA; although these were rare for both tests. The economic evaluation showed DUS dominated the other alternatives when the whole leg was assessed, by presenting higher effectiveness at a lower cost per quality-adjusted life-year (QALY; i.e. 13,646 pounds per QALY). When the assessment was limited to a section of the leg, either above the knee or below the knee, 2D TOF MRA was the most cost-effective preoperative diagnostic strategy. The incremental cost per QALY for below-the-knee comparisons was equal to 37,024 pounds when 2D TOF MRA was compared with DUS. For above-the-knee comparisons, 2D TOF MRA presented the lowest cost and slightly lower effectiveness compared with CE MRA, with a cost per QALY equal to 13,442 pounds. CONCLUSIONS: The results of the review suggest that CE MRA has a better overall diagnostic accuracy than CTA or DUS, and that CE MRA is generally preferred by patients over CA. Where available, CE MRA may be a viable alternative to CA. The only controlled trial suggested that the results of DUS were comparable to those of CA, in terms of surgical planning and outcome. This finding conflicts with the results of diagnostic accuracy studies, which reported poor estimates of accuracy for DUS in comparison with CA. There was insufficient evidence to evaluate the usefulness of CTA for the assessment of PAD, particularly newer techniques. The results of the economic modelling suggest that for PAD patients for whom the whole leg is evaluated by a preoperative diagnostic test, DUS dominates the other alternatives by presenting higher effectiveness at a lower cost per QALY. However, when the analysis of stenosis is limited to a section of the leg, either above the knee or below the knee, 2D TOF MRA appears to be the most cost-effective preoperative diagnostic strategy. Further research is needed into a number of areas including the relative clinical effectiveness of the available imaging tests, in terms of surgical planning and postoperative outcome.

Pressure relieving support surfaces: a randomised evaluation.

OBJECTIVES: To determine differences between alternating pressure overlays and alternating pressure replacement mattresses with respect to the development of new pressure ulcers, healing of existing pressure ulcers, patient acceptability and cost-effectiveness of the different pressure-relieving surfaces. Also to investigate the specific additional impact of pressure ulcers on patients' well-being. DESIGN: A multicentre, randomised, controlled, open, fixed sample, parallel-group trial with equal randomisation was undertaken. The trial used remote, concealed allocation and intention-to-treat (ITT) analysis. The main trial design was supplemented with a qualitative study involving a purposive sample of 20-30 patients who developed pressure ulcers, to assess the impact of the pressure ulcers on their well-being. In addition, a focus group interview was carried out with clinical research nurses, who participated in the PRESSURE (Pressure RElieving Support SUrfaces: a Randomised Evaluation) Trial, to explore the experiences of their role and observations of pressure area care. SETTING: The study took place in 11 hospital-based research centres within six NHS trusts in England. PARTICIPANTS: Acute and elective patients aged 55 years or older and admitted to vascular, orthopaedic, medical or care of the elderly wards in the previous 24 hours were investigated. INTERVENTIONS: Patients were randomised to either an alternating pressure overlay or an alternating pressure mattress replacement, with mattress specifications clearly defined to enable the inclusion of centres using products from different manufacturers, and to exclude hybrid mattress systems (which either combine foam or constant low pressure with alternating pressure in one mattress, or can be used as either an overlay or a replacement mattress). MAIN OUTCOME MEASURES: Development of a new pressure ulcer (grade < or =2, i.e. partial-thickness wound involving epidermis/dermis only) on any skin site. Also healing of existing pressures ulcers, patient acceptability and cost-effectiveness. RESULTS: In total, 6155 patients were assessed for eligibility to the trial and 1972 were randomised: 990 to the alternating pressure overlay (989 after one postrandomisation exclusion) and 982 to the alternating pressure mattress replacement. ITT analysis found no statistically significant difference in the proportions of patients developing a new pressure ulcer of grade 2 or above [10.7% overlay patients, 10.3% mattress replacement patients, a difference of 0.4%, 95% confidence interval (CI) -2.3 to 3.1%, p = 0.75]. When logistic regression analysis was used to adjust for minimisation factors and prespecified baseline covariates, there was no difference between the mattresses with respect to the odds of ulceration (odds ratio 0.94, 95% CI 0.68 to 1.29). There was no evidence of a difference between the mattress groups with respect to time to healing (p = 0.86). The Kaplan-Meier estimate of the median time to healing was 20 days for each intervention. More patients allocated overlays requested mattress changes due to dissatisfaction (23.3%) than mattress replacement patients (18.9%, p = 0.02) and more than one-third of patients reporting difficulties associated with movement in bed and getting into or out of bed. There is a higher probability (64%) that alternating mattress replacements are cost-saving; they were associated with lower overall costs (74.50 pounds sterling per patient on average, mainly due to reduced length of stay) and greater benefits (a delay in time to ulceration of 10.64 days on average). Patients' accounts highlighted that the development of a pressure ulcer could be pivotal in the trajectory from illness to recovery, by preventing full recovery or causing varied impacts on their quality of life. CONCLUSIONS: There is no difference between alternating pressure mattress replacements and overlays in terms of the proportion of patients developing new pressure ulcers; however, alternating pressure mattress replacements are more likely to be cost-saving. The results suggest that when renewing alternating pressure surfaces or ordering equipment within a rental contract, mattress replacements should be specified; however, overlays are acceptable if no replacement mattress is available. Similarly, patient preferences can be supported, without any great increase in risk, if individual patients request an overlay rather than a replacement mattress. Further research could include a randomised controlled trial comparing alternating pressure mattress replacements and high-specification foam mattresses in patients at moderate to high risk; an accurate costing study to understand better how much pressure ulcers cost health and social services in the UK; and trials in higher risk groups of patients. Also future trials should measure time to ulceration as the primary end-point, since this is more informative economically and possibly also from a patient and clinical perspective.

Congenital brachial palsy: incidence, causes, and outcome in the United Kingdom and Republic of Ireland.

OBJECTIVES: To determine the incidence and study the causes and outcome of congenital brachial palsy (CBP). DESIGN: Active surveillance of newborn infants using the British Paediatric Surveillance Unit notification system and follow up study of outcome at 6 months of age. SETTING: The United Kingdom and Republic of Ireland. PARTICIPANTS: Newborn infants presenting with a flaccid paresis of the arm (usually one, rarely both) born between April 1998 and March 1999. MAIN OUTCOME MEASURES: Extent of the lesion at birth and degree of recovery at 6 months of age. FINDINGS: There were 323 confirmed cases giving an incidence of 0.42 per 1000 live births (1 in 2300). Significant associated risk factors in comparison with the normal population were shoulder dystocia (60% v 0.3%), high birth weight with 53% infants weighing more than the 90th centile, and assisted delivery (relative risk (RR) 3.4, 95% confidence interval (CI) 2.9 to 3.9, p = 0.0001). There was a considerably lower risk of CBP in infants delivered by caesarean section (RR 7, 95% CI 2 to 56, p = 0.002). At about 6 months of age, about half of the infants had recovered fully, but the remainder showed incomplete recovery including 2% with no recovery. The relative risk of partial or no recovery in infants with extensive lesions soon after birth compared with those with less extensive lesions was 11.28 (95% CI 2.38 to 63.66, p = 0.000005). CONCLUSIONS: The incidence of CBP in the United Kingdom and Republic of Ireland is strikingly similar to that previously reported nearly 40 years ago. Most cases are due to trauma at delivery, which is not necessarily excessive or inappropriate. Given the uncertainty about the appropriate management of these infants, serious consideration should be given to a formal clinical trial of microsurgical nerve repair.

Chemical pathology out-of-hours services in Beaumont and Blanchardstown hospitals following the introduction of continuous accident and emergency cover for local catchment areas.

The effect on the Chemical Pathology 'on-call' services at Beaumont and Blanchardstown hospitals of the change in the Accident and Emergency service from a regular roster covering the northern half of Dublin to continuous local catchment area cover is reported. At Beaumont, the number of patient specimens each night from the A&E department is similar to the peak level which occurred approximately every third day under the old rota system. The total continuous demand in the hospital is about 10% higher than the previously reported peak demand. At Blanchardstown by contrast, the demand from A&E has fallen by about 60% from the previous peak but services to inpatients have increased by 50% over the previous year's published figure. Thus the on-call demands for Chemical Pathology services continue to grow but there has been a large shift in demand towards the hospital with the greater catchment area.

Changing patterns of demand for chemical pathology on-call services in four north Dublin Hospitals.

Developments in the demand for out-of-hours chemical pathology over the period when the Richmond and Jervis St. hospitals amalgamated and moved to a new hospital at Beaumont are presented alongside the similar workload from Blanchardstown Hospital whose laboratory services remained unchanged during the period. The requests from the Accident and Emergency (A&E) departments before and after midnight are also detailed. Data is presented from the Richmond from 1986 and from the other hospitals from 1987 using the first 17 rostered on-call nights of each year. With the exception of Beaumont where the diversity of tests requested was such that the working day had effectively extended, the work load consisted largely of urea and electrolytes, glucose, blood gases and amylase. The demand continued to rise. In Blanchardstown, the total number of patient specimens rose by 39% over two years and the volume increase in A&E was 69% over the same period. The number of specimens from inpatients at Beaumont in 1989 was 49% greater than the combined total from Jervis St. and the Richmond in 1987 and the total patient specimens rose by 14% from 1988 to 1989.