The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study.

BACKGROUND: Giant cell arteritis (GCA) is a relatively common form of primary systemic vasculitis, which, if left untreated, can lead to permanent sight loss. We compared ultrasound as an alternative diagnostic test with temporal artery biopsy, which may be negative in 9-61% of true cases. OBJECTIVE: To compare the clinical effectiveness and cost-effectiveness of ultrasound with biopsy in diagnosing patients with suspected GCA. DESIGN: Prospective multicentre cohort study. SETTING: Secondary care. PARTICIPANTS: A total of 381 patients referred with newly suspected GCA. MAIN OUTCOME MEASURES: Sensitivity, specificity and cost-effectiveness of ultrasound compared with biopsy or ultrasound combined with biopsy for diagnosing GCA and interobserver reliability in interpreting scan or biopsy findings. RESULTS: We developed and implemented an ultrasound training programme for diagnosing suspected GCA. We recruited 430 patients with suspected GCA. We analysed 381 patients who underwent both ultrasound and biopsy within 10 days of starting treatment for suspected GCA and who attended a follow-up assessment (median age 71.1 years; 72% female). The sensitivity of biopsy was 39% [95% confidence interval (CI) 33% to 46%], which was significantly lower than previously reported and inferior to ultrasound (54%, 95% CI 48% to 60%); the specificity of biopsy (100%, 95% CI 97% to 100%) was superior to ultrasound (81%, 95% CI 73% to 88%). If we scanned all suspected patients and performed biopsies only on negative cases, sensitivity increased to 65% and specificity was maintained at 81%, reducing the need for biopsies by 43%. Strategies combining clinical judgement (clinician's assessment at 2 weeks) with the tests showed sensitivity and specificity of 91% and 81%, respectively, for biopsy and 93% and 77%, respectively, for ultrasound; cost-effectiveness (incremental net monetary benefit) was £485 per patient in favour of ultrasound with both cost savings and a small health gain. Inter-rater analysis revealed moderate agreement among sonographers (intraclass correlation coefficient 0.61, 95% CI 0.48 to 0.75), similar to pathologists (0.62, 95% CI 0.49 to 0.76). LIMITATIONS: There is no independent gold standard diagnosis for GCA. The reference diagnosis used to determine accuracy was based on classification criteria for GCA that include clinical features at presentation and biopsy results. CONCLUSION: We have demonstrated the feasibility of providing training in ultrasound for the diagnosis of GCA. Our results indicate better sensitivity but poorer specificity of ultrasound compared with biopsy and suggest some scope for reducing the role of biopsy. The moderate interobserver agreement for both ultrasound and biopsy indicates scope for improving assessment and reporting of test results and challenges the assumption that a positive biopsy always represents GCA. FUTURE WORK: Further research should address the issue of an independent reference diagnosis, standards for interpreting and reporting test results and the evaluation of ultrasound training, and should also explore the acceptability of these new diagnostic strategies in GCA. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

PRomotion Of Physical activity through structured Education with differing Levels of ongoing Support for people at high risk of type 2 diabetes (PROPELS): study protocol for a randomized controlled trial.

BACKGROUND: The prevention of type 2 diabetes is recognised as a health care priority. Lifestyle change has proven effective at reducing the risk of type 2 diabetes, but limitations in the current evidence have been identified in: the promotion of physical activity; availability of interventions that are suitable for commissioning and implementation; availability of evidence-based interventions using new technologies; and physical activity promotion among ethnic minorities. We aim to investigate whether a structured education programme with differing levels of ongoing support, including text-messaging, can increase physical activity over a 4 year period in a multi-ethnic population at high risk of diabetes. METHODS/DESIGN: A multi-centre randomised controlled trial, with follow-up at 12 and 48 months. The primary outcome is change in ambulatory activity at 48 months. Secondary outcomes include changes to markers of metabolic, cardiovascular, anthropometric and psychological health along with cost-effectiveness. Participants aged 40-74 years for White European, or 25-74 years for South Asians, with an HbA1c value of between 6.0 and < 6.4% (42 and 47 mmol/mol) or with a previously recorded plasma glucose level or HbA1c value within the high risk (prediabetes) range within the last five years, are invited to take part in the trial. Participants are identified through primary care, using an automated diabetes risk score within their practice database, or from a database of previous research participants. Participants are randomly assigned to either: 1) the control group who receive a detailed advice leaflet; 2) the Walking Away group, who receive the same leaflet and attend a 3 hour structured education programme with annual maintenance sessions delivered in groups; or 3) the Walking Away Plus group, who receive the leaflet, attend the structured education programme with annual maintenance sessions, plus receive follow-on support through highly-tailored text-messaging and telephone calls to help to aid pedometer use and behaviour change. DISCUSSION: This study will provide new evidence for the long-term effectiveness of a structured education programme focused on physical activity, conducted within routine care in a multi-ethnic population in the UK. It will also investigate the impact of different levels of ongoing support and the cost-effectiveness of each intervention. TRIAL REGISTRATION: ISRCTN83465245 Trial registration date: 14/06/2012.

The cost-effectiveness of testing strategies for type 2 diabetes: a modelling study.

BACKGROUND: An estimated 850,000 people have diabetes without knowing it and as many as 7 million more are at high risk of developing it. Within the NHS Health Checks programme, blood glucose testing can be undertaken using a fasting plasma glucose (FPG) or a glycated haemoglobin (HbA1c) test but the relative cost-effectiveness of these is unknown. OBJECTIVES: To estimate and compare the cost-effectiveness of screening for type 2 diabetes using a HbA1c test versus a FPG test. In addition, to compare the use of a random capillary glucose (RCG) test versus a non-invasive risk score to prioritise individuals who should undertake a HbA1c or FPG test. DESIGN: Cost-effectiveness analysis using the Sheffield Type 2 Diabetes Model to model lifetime incidence of complications, costs and health benefits of screening. SETTING: England; population in the 40-74-years age range eligible for a NHS health check. DATA SOURCES: The Leicester Ethnic Atherosclerosis and Diabetes Risk (LEADER) data set was used to analyse prevalence and screening outcomes for a multiethnic population. Alternative prevalence rates were obtained from the literature or through personal communication. METHODS: (1) Modelling of screening pathways to determine the cost per case detected followed by long-term modelling of glucose progression and complications associated with hyperglycaemia; and (2) calculation of the costs and health-related quality of life arising from complications and calculation of overall cost per quality-adjusted life-year (QALY), net monetary benefit and the likelihood of cost-effectiveness. RESULTS: Based on the LEADER data set from a multiethnic population, the results indicate that screening using a HbA1c test is more cost-effective than using a FPG. For National Institute for Health and Care Excellence (NICE)-recommended screening strategies, HbA1c leads to a cost saving of £12 and a QALY gain of 0.0220 per person when a risk score is used as a prescreen. With no prescreen, the cost saving is £30 with a QALY gain of 0.0224. Probabilistic sensitivity analysis indicates that the likelihood of HbA1c being more cost-effective than FPG is 98% and 95% with and without a risk score, respectively. One-way sensitivity analyses indicate that the results based on prevalence in the LEADER data set are insensitive to a variety of alternative assumptions. However, where a region of the country has a very different joint HbA1c and FPG distribution from the LEADER data set such that a FPG test yields a much higher prevalence of high-risk cases relative to HbA1c, FPG may be more cost-effective. The degree to which the FPG-based prevalence would have to be higher depends very much on the uncertain relative uptake rates of the two tests. Using a risk score such as the Leicester Practice Database Score (LPDS) appears to be more cost-effective than using a RCG test to identify individuals with the highest risk of diabetes who should undergo blood testing. LIMITATIONS: We did not include rescreening because there was an absence of required relevant evidence. CONCLUSIONS: Based on the multiethnic LEADER population, among individuals currently attending NHS Health Checks, it is more cost-effective to screen for diabetes using a HbA1c test than using a FPG test. However, in some localities, the prevalence of diabetes and high risk of diabetes may be higher for FPG relative to HbA1c than in the LEADER cohort. In such cases, whether or not it still holds that HbA1c is likely to be more cost-effective than FPG depends on the relative uptake rates for HbA1c and FPG. Use of the LPDS appears to be more cost-effective than a RCG test for prescreening. FUNDING: The National Institute for Health Research Health Technology Assessment programme.