Biomedical subjects

Fiona C Sampson

Publications and source records attributed to Fiona C Sampson.

6 recordsLinked to original sources

PubMed2006

The accuracy of MRI in diagnosis of suspected deep vein thrombosis: systematic review and meta-analysis.

Magnetic resonance imaging (MRI) may be used to diagnose deep vein thrombosis (DVT) in patients for whom ultrasound examination is inappropriate or unfeasible. We undertook a systematic review of the literature and meta-analysis to estimate the diagnostic accuracy of MRI for DVT. We searched databases of medical literature and citation lists of retrieved articles. We selected studies that compared MRI with a reference standard in patients with suspected DVT or suspected pulmonary embolus, or high-risk asymptomatic patients. Data were analysed by random effects meta-analysis. We included 14 articles in the meta-analysis. Most compared MRI with venography in patients with clinically suspected DVT. The pooled estimate of sensitivity was 91.5% (95% CI: 87.5-94.5%) and the pooled estimate of specificity was 94.8% (95% CI: 92.6-96.5%). Sensitivity for proximal DVT was higher than sensitivity for distal DVT (93.9% versus 62.1%). However, pooled estimates should be interpreted with caution as estimates of both sensitivity and specificity were subject to significant heterogeneity (P<0.001). Individual studies reported sensitivity ranging from zero to 100%, while specificity ranged from 43 to 100%. MRI has equivalent sensitivity and specificity to ultrasound for diagnosis of DVT, but has been evaluated in many fewer studies, using a variety of different techniques.

Humans↗

PubMed2005

Advanced access: more than just GP waiting times?

BACKGROUND: Advanced access has been forwarded as a strategy for reducing waiting times in primary care; however, previous evaluations have raised important issues regarding its appropriateness. OBJECTIVES: The objectives of this paper are to assess the impact of advanced access on patient access to primary care services, and its broader effects on stakeholders. METHODS: A quantitative analysis of appointment data on 462 practices implementing advanced access, together with qualitative analysis of open survey responses and interviews with 28 practice staff. Appointment data recorded time to third available appointment for GP and practice nurse, together with the percentage of patients seen on their day of choice. Themes were identified from the interviews and survey responses and related to issues identified in previous research. RESULTS: The implementation of advanced access was associated with reductions in time to see practice nurses as well as GPs, and increases in the proportion of patients being seen on their day of choice. Interviewee and survey responses suggested that practice population characteristics may impact on the model, and some patient groups may be disadvantaged from the changes in the appointment systems seen in this study. Whilst experiences were mixed, the potential for broader changes to working practices of all practice staff was evident. CONCLUSIONS: In general, these results suggest that advanced access can have a positive impact across several aspects of primary care services, and not just the availability of GP appointments. However, it also highlights some problems, in that waiting times worsened in some practices and there were concerns that some vulnerable groups may be disadvantaged.

Appointments and Schedules↗

PubMed2005

Meta-analysis: The value of clinical assessment in the diagnosis of deep venous thrombosis.

BACKGROUND: Clinical assessment of suspected deep venous thrombosis (DVT) should be based on systematically evaluated evidence. PURPOSE: To determine whether clinical findings, risk scores, and physicians' empirical judgments affect the likelihood of detecting DVT on definitive testing. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, ACP Journal Club, and citation lists (1966 to January 2005). STUDY SELECTION: Cohort studies published in English, French, Spanish, or Italian that compared clinical assessment with a reference standard. DATA EXTRACTION: The authors extracted standardized data, including setting, exclusions, population characteristics, reference standard, and results, and assessed quality against validated criteria. DATA SYNTHESIS: The authors combined data by using random-effects meta-analysis and, if appropriate, used meta-regression to identify covariates that predicted diagnostic accuracy. Only malignancy (likelihood ratio [LR], 2.71), previous DVT (LR, 2.25), recent immobilization (LR, 1.98), difference in calf diameter (LR, 1.80), and recent surgery (LR, 1.76) were useful for ruling in DVT, while only absence of calf swelling (LR, 0.67) or difference in calf diameter (LR, 0.57) was useful for ruling out DVT. The Wells clinical score was more valuable than the individual characteristics; it stratified patients into groups with high (LR, 5.2), intermediate, and low (LR, 0.25) probability of DVT. The Wells score seemed able to stratify patients by risk only for proximal DVT, and it performed better in cohorts that were younger or excluded patients with previous thromboembolism. LIMITATIONS: Pooled estimates were subject to substantial heterogeneity. This may limit extrapolation between observers and settings. Only published studies were included, so findings may be subject to publication bias. CONCLUSION: Individual clinical features are of limited value in diagnosing DVT. Overall assessment of clinical probability by using the Wells score is more useful.

Humans↗

PubMed2004

Nurses' views of using computerized decision support software in NHS Direct.

BACKGROUND: Nurses working in NHS Direct, the 24-hour telephone advice line in England, use computerized decision support software to recommend to callers the most appropriate service to contact, or to advise on self-care. AIMS: To explore nurses' views of their roles and the computerized decision support software in NHS Direct. METHODS: Qualitative analysis of semi-structured interviews with 24 NHS Direct nurses in 12 sites. FINDINGS: Nurses described both the software and themselves as essential to the clinical decision-making process. The software acted as safety net, provider of consistency, and provider of script, and was relied upon more when nurses did not have clinical knowledge relevant to the call. The nurse handled problems not covered by the software, probed patients for the appropriate information to enter into the software, and interpreted software recommendations in the light of contextual information which the software was unable to use. Nurses described a dual process of decision-making, with the nurse as active decision maker looking for consensus with the software recommendation and ready to override recommendations made by the software if necessary. However, nurses' accounts of the software as a guide, prompt or support did not fully acknowledge the power of the software, which they are required to use, and the recommendation of which they are required to follow under some management policies. Over time, the influence of nurse and software merges as nurses internalize the software script as their own knowledge, and navigate the software to produce recommendations that they feel are most appropriate. CONCLUSIONS: The nurse and the software have distinct roles in NHS Direct, although the effect of each on the clinical decision-making process may be difficult to determine in practice.

Attitude of Health Personnel↗

PubMed2004

Evaluation of advanced access in the national primary care collaborative.

BACKGROUND: An aim of the National Primary Care Collaborative is to improve quality and access for patients in primary care using principles of Advanced Access. AIMS: To determine whether Advanced Access led to improved availability of appointments with general practitioners (GPs) and to examine GPs' views of the process. DESIGN: Observational study. SETTING: Four hundred and sixty-two general practices in England participating in four waves of the collaborative during 2000 and 2001. METHOD: Regression analysis of the collaborative's monthly data on the availability of GP appointments for the 352 practices in waves 1-3, and a postal survey of lead GPs in all four waves. The main outcome measures were the change in mean time to the third available appointment with GPs, and the proportion of GPs thinking it worthwhile participating in the collaborative. RESULTS: The time to the third available appointment improved from a mean of 3.6 to 1.9 days, difference = 1.7 days, 95% confidence interval (CI)= 1.4 to 2.0 days. It improved in two-thirds of practices (66% [219/331]), remained the same in 16% (53/331), and worsened in 18% (59/331). The majority of GPs in all four waves, 83% (308/371, 95% CI = 79 to 87), felt that it was worthwhile participating in the collaborative, although one in 12 practices would not recommend it. One-fifth of GPs cited a lack of resources as a constraint, and some expressed concerns about the trade-off between immediate access and continuity of care. CONCLUSION: Advanced Access helped practices to improve availability of GP appointments, and was well received by the majority of practices.

Appointments and Schedules↗

PubMed2002

Functional benefits and cost/benefit analysis of continuous intrathecal baclofen infusion for the management of severe spasticity.

OBJECT: Intrathecally delivered baclofen has been used as a treatment for severe spasticity since 1984. Despite this, there are uncertainties surrounding the benefits of treatment and the costs involved. The authors assessed the evidence of benefits and identified costs and the cost/benefit ratio for continuous intrathecal baclofen infusion in the treatment of severe spasticity. METHODS: A systematic literature review was conducted to estimate the effect of continuous intrathecal baclofen infusion on function and quality-of-life (QOL) measures in patients with severe spasticity. Outcomes were related to standard QOL scores to estimate potential gains in quality-adjusted life years (QALYs). Information on the costs of continuous intrathecal baclofen infusion was obtained from hospitals in the United Kingdom. This information was combined to estimate the cost/benefit ratio for the use of continuous intrathecal baclofen infusion in patients with different levels of disability from severe spasticity. Studies indicate that bedbound patients are likely to improve their mobility and become able to sit out of bed. Patients with severe spasm-related pain are likely to have major improvement or complete resolution of this pain. Many other benefits are also reported. Such benefits are related to costs per QALY in the range of 6,900 pounds to 12,800 pounds ($10,550-$19,570 US). CONCLUSIONS: In carefully selected patients who have not responded to less invasive treatments, continuous intrathecal baclofen infusion is likely to lead to worthwhile functional benefits. Continuous intrathecal baclofen infusion has an acceptable cost/benefit ratio compared with other interventions that are funded by the health service.

Adolescent↗