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David Parkin

Publications and source records attributed to David Parkin.

14 recordsLinked to original sources
PubMed2006

Is there a case for using visual analogue scale valuations in cost-utility analysis?

This paper critically reviews theoretical and empirical propositions regarding visual analogue scale (VAS) valuations of health states and their use in cost-utility analysis (CUA). A widely repeated assertion in the economic evaluation literature is the inferiority, on theoretical grounds, of VAS valuations. Five common criticisms are: VAS lacks a theoretical foundation; VAS values are not 'choice based'; VAS values are not consistent with utility-under-uncertainty requirements; context and range effects observed in VAS valuation data mean that they cannot even be considered to represent measurable value functions; and when completing a VAS, people are not trying to express values. We address each of these points: the VAS does have a theoretical basis, being entirely consistent with the non-welfarist foundations of QALYs and CUA; the 'choiceless' nature of the VAS is incorrectly judged by stated preference criteria relevant to monetary rather than health state valuations, and VAS valuations do in any case involve an element of choice; because valuations are intended for use in social decision-making, it may be advantageous that VAS values are elicited under conditions of certainty; although there are measurement problems with the VAS, means such as better design and transformations of data can deal with these; and with any method of eliciting values, it is unrealistic to expect people consciously to think in terms of social science constructs such as utilities.Moreover, there are problems, both theoretical and empirical, with alternative methods. Selection of the appropriate valuation method should be based on empirical performance, and in this the VAS has important advantages. We conclude that there are strong grounds for disputing the consensus view against the VAS and challenge those who hold it to deploy more convincing arguments and evidence in favour of alternative methods. However, we identify areas where further research is required to establish and consolidate the potential of the VAS as a valuation method.

Costs and Cost Analysis↗
PubMed2004

Phase III randomized trial of docetaxel-carboplatin versus paclitaxel-carboplatin as first-line chemotherapy for ovarian carcinoma.

BACKGROUND: Chemotherapy with a platinum agent and a taxane (paclitaxel) is considered the standard of care for treatment of ovarian carcinoma. We compared the combination of docetaxel-carboplatin with the combination of paclitaxel-carboplatin as first-line chemotherapy for stage Ic-IV epithelial ovarian or primary peritoneal cancer. METHODS: We randomly assigned 1077 patients to receive docetaxel at 75 mg/m2 of body surface area (1-hour intravenous infusion) or paclitaxel at 175 mg/m2 (3-hour intravenous infusion). Both treatments then were followed by carboplatin to an area under the plasma concentration-time curve of 5. The treatments were repeated every 3 weeks for six cycles; in responding patients, an additional three cycles of single-agent carboplatin was permitted. Survival curves were calculated by the Kaplan-Meier method, and hazard ratios were estimated with the Cox proportional hazards model. All statistical tests were two-sided. RESULTS: After a median follow-up of 23 months, both groups had similar progression-free survival (medians of 15.0 months for docetaxel-carboplatin and 14.8 months for paclitaxel-carboplatin; hazard ratio [HR] docetaxel-paclitaxel = 0.97, 95% confidence interval [CI] = 0.83 to 1.13; P = .707), overall survival rates at 2 years (64.2% and 68.9%, respectively; HR = 1.13, 95% CI = 0.92 to 1.39; P = .238), and objective tumor (58.7% and 59.5%, respectively; difference between docetaxel and paclitaxel = -0.8%, 95% CI = -8.6% to 7.1%; P = .868) and CA-125 (75.8% and 76.8%, respectively; difference docetaxel-paclitaxel = -1.0%, 95% CI = -7.2% to 5.1%; P = .794) response rates. However, docetaxel-carboplatin was associated with substantially less overall and grade 2 or higher neurotoxicity than paclitaxel-carboplatin (grade > or =2 neurosensory toxicity in 11% versus 30%, difference = 19%, 95% CI = 15% to 24%; P<.001; grade > or =2 neuromotor toxicity in 3% versus 7%, difference = 4%, 95% CI = 1% to 7%; P<.001). Treatment with docetaxel-carboplatin was associated with statistically significantly more grade 3-4 neutropenia (94% versus 84%, difference = 11%, 95% CI = 7% to 14%; P<.001) and neutropenic complications than treatment with paclitaxel-carboplatin, although myelosuppression did not influence dose delivery or patient safety. Global quality of life was similar in both arms, but substantive differences in many symptom scores favored docetaxel. CONCLUSIONS: Docetaxel-carboplatin appears to be similar to paclitaxel-carboplatin in terms of progression-free survival and response, although longer follow-up is required for a definitive statement on survival. Thus, docetaxel-carboplatin represents an alternative first-line chemotherapy regimen for patients with newly diagnosed ovarian cancer.

Adult↗
PubMed2004

Does NICE have a cost-effectiveness threshold and what other factors influence its decisions? A binary choice analysis.

The decisions made by the National Institute for Clinical Excellence (NICE) give rise to two questions: how is cost-effectiveness evidence used to make judgements about the 'value for money' of health technologies? And how are factors other than cost-effectiveness taken into account? The aim of this paper is to explore NICE's cost-effectiveness threshold(s) and the tradeoffs between cost effectiveness and other factors apparent in its decisions. Binary choice analysis is used to reveal the preferences of NICE and to consider the consistency of its decisions. For each decision to accept or reject a technology, explanatory variables include: the cost per life year or per QALY gained; uncertainty regarding cost effectiveness; the net cost to the NHS; the burden of disease; the availability (or not) of alternative treatments; and specific factors indicated by NICE. Results support the broad notion of a threshold, where the probability of rejection increases as the cost per QALY increases. Cost effectiveness, together with uncertainty and the burden of disease, explain NICE decisions better than cost effectiveness alone. The results suggest a threshold somewhat higher than NICEs stated 'range of acceptable cost effectiveness' of pound 20,000-30,000 British pounds per QALY--although the exact meaning of a 'range' in this context remains unclear.

Cost-Benefit Analysis↗
PubMed2004

Use of a visual analogue scale in a daily patient diary: modelling cross-sectional time-series data on health-related quality of life.

An economic evaluation of beta interferon therapy collected quality of life data from 62 people with relapsing-remitting multiple sclerosis, currently in remission. Each completed a postal questionnaire consisting of the Euroqol EQ-5D questionnaire, the MSQOL-54 (a disease-specific measure incorporating the SF36) and other data including health services use. This was completed at the beginning and end of 6-weeks during which a daily diary was kept. The diary asked about daily activities, symptoms experienced, the impact of symptoms, general health status and current health status using the Euroqol Visual Analogue Scale (EQ VAS). The diary had an excellent completion rate, producing data with good face validity. The resulting cross-sectional time-series data provide information about the stability and variability of the EQ VAS in repeated measurement and its sensitivity to health state changes. EQ VAS scores were stable at the population level over time; greater variation in scores was observed between rather than within individuals. Panel data techniques are used to relate EQ VAS scores to recorded symptoms and baseline general health status, paying particular attention to the role of individual heterogeneity and the dynamic nature of responses. The EQ VAS was sensitive to the presence of symptoms, their severity and their type. It is concluded that appropriately analysed panel data can provide insights useful in the measurement of health-related quality of life.

Adult↗
PubMed2003

WHO evaluates NICE.

Explore the source record for details and available documents.

Academies and Institutes↗
PubMed2003

A single European currency for EQ-5D health states. Results from a six-country study.

The EQ-5D questionnaire is a widely used generic instrument for describing and valuing health that was developed by the EuroQol Group. A primary objective of the EuroQol Group is the investigation of values for health states in the general population in different countries. As part of the EuroQol enterprise 11 population surveys were carried out in six Western European countries (Finland, Germany, The Netherlands, Spain, Sweden and the UK) to value health states as defined by the EQ-5D using a standardised visual analogue scale (EQ-5D VAS). This contribution reports how a European set of general population preference weights was derived from the data collected in the 11 valuation studies. The scores from this set of preference weights can be applied to generate a VAS-based weighted health status index for all the potential 243 EQ-5D health states for use in multi-national studies. To estimate the preference weights a multi-level regression analysis was performed on 82,910 valuations of 44 EQ-5D health states elicited from 6,870 respondents. Stable and plausible solutions were found for the model parameters. The R(2) value was 75%. The analysis showed that the major source of variance, apart from 'random error', was variance between individuals (28.3% of the total residual variance). These results suggest that VAS values for EQ-5D health states in six Western European countries can be described by a common model.

Journal Article↗
PubMed2003

Funding fertility: issues in the allocation and distribution of resources to assisted reproduction technologies.

The appropriate level and source of funds for assisted reproduction technologies (ARTs), in particular IVF, have been controversial in most developed economies. Funding of fertility services internationally is characterized by low public (or other third party) funding, a greater reliance on user-pays than in most other health services, and variations in funding and provision. This article describes the characteristics of infertility as a condition and its treatment that have been used as a rationale for its exclusion from an otherwise comprehensive coverage of health services. The challenges these characteristics pose for the use of economic evaluation to inform resource allocation are discussed. Most economic evaluations have focused on the cost effectiveness of alternative infertility treatments. These evaluations provide important information, but do not inform the real issue at stake: what is the appropriate allocation of funds to ARTs, given that it involves sacrificing improvements in health in other areas? Cost utility analysis - the method of economic appraisal preferred by most agencies charged with making such decisions (including the National Institute of Clinical Excellence in the UK) - is ill-equipped to deal with the benefits produced by ARTs. Alternative methods are available, but require decision makers to weigh up very different sorts of evidence. Demonstration of the willingness to pay for the benefits of ARTs can be used to support public decisions but, conversely, also implies that those who can pay will pay in a private market. Ultimately, decisions about the inclusion or otherwise of ARTs in collectively funded health systems probably rest as much on judgments about equity in access as value for money. Given that this is the case, public funding of IVF should be accompanied by the development of agreed criteria for the prioritization of potential recipients, to ensure treatment is targeted at those for whom it is most effective and that access is consistent and fair.

Adult↗
PubMed2003

Patients' views of explicit rationing: what are the implications for health service decision-making?

Patient groups in England and Wales have expressed concerns about the decision-making processes of the National Institute for Clinical Excellence (NICE), the body responsible for explicit rationing. Five key issues were identified by the Multiple Sclerosis Society regarding NICE appraisals and guidance: they focus too narrowly on costs to the National Health Service; quality-adjusted life-years are an inadequate measure of health gain, particularly for long-term conditions; NICE takes too conservative a view of long-term benefits; NICE's cost-effectiveness threshold is inappropriate; and NICE evaluations fail to capture patients' personal experiences of their condition and treatments. We question the veracity of some of these arguments and, where appropriate, suggest ways in which NICE's processes might be strengthened.

Academies and Institutes↗
PubMed2003

Efficiency and productivity change in the English National Health Service: can data envelopment analysis provide a robust and useful measure?

OBJECTIVE: Several tools are available to health care organisations in England to measure efficiency, but these are widely reported to be unpopular and unusable. Moreover, they do not have a sound conceptual basis. This paper describes the development and evaluation of a user-friendly tool that organisations can use to measure their efficiency, based on the technique of data envelopment analysis (DEA), which has a firm basis in economic theory. METHODS: Routine data from 57 providers and 14 purchasing organisations in one region of the English National Health Service (NHS) for 1994-1996 were used to create information on efficiency based on DEA. This was presented to them using guides that explained the information and how it was to be used. They were surveyed to elicit their views on current measures of efficiency and on the potential use of the DEA-based information. RESULTS: The DEA measure demonstrated considerable scope for improvements in health service efficiency. There was a very small improvement over time with larger changes in some hospitals than others. Overall, 80% of those surveyed gave high scores for the potential usefulness of the DEA-based measures compared with 9-45% for existing methods. The quality of presentation of the information was also consistently high. CONCLUSIONS: There is dissatisfaction with efficiency information currently available to the NHS. DEA produces potentially useful information, which is easy to use and can be easily explained to and understood by potential users. The next step would be the implementation, on a developmental basis, of a routine DEA-based information system.

Data Interpretation, Statistical↗
PubMed2003

The cost of microwave endometrial ablation under different anaesthetic and clinical settings.

OBJECTIVE: To compare the costs of microwave endometrial ablation under local anaesthetic and general anaesthetic in an operating theatre and to estimate the cost of performing treatment under local anaesthetic in a dedicated clinic setting. DESIGN: The costing study was undertaken alongside a randomised controlled trial comparing the acceptability of microwave endometrial ablation using local versus general anaesthetic in a theatre setting. SETTING: Department of Gynaecology, Aberdeen Royal Infirmary, Scotland. SAMPLES: One hundred and twenty-seven women undergoing microwave endometrial ablation who had been randomly allocated to general or local anaesthetic. METHODS: Health and non-health service resource use was recorded prospectively. Data on resource use were combined with unit costs estimated using standardised methods to determine the cost per patient for microwave endometrial ablation under local or general anaesthetic in theatre. A model was developed to estimate the health service cost of microwave endometrial ablation under local anaesthetic in a clinic setting. MAIN OUTCOME MEASURES: Health and non-health service costs. RESULTS: There was little difference in cost when treatments were performed under local or general anaesthetic in theatre. The median health and non-health cost of microwave endometrial ablation was 440 pounds and 120 pounds, respectively, under general anaesthetic and 428 pounds and 125 pounds per women under local anaesthetic. The health service cost of microwave endometrial ablation using local anaesthetic in a clinic setting was estimated to be 432 pounds per treatment; however, this varied from 389 pounds to 491 pounds in the sensitivity analysis. CONCLUSION: There are minimal cost savings to the patient or health service from using local rather than general anaesthetic for microwave endometrial ablation in a theatre setting. Cost modelling suggests that in a clinic setting microwave endometrial ablation has a similar cost to theatre based treatment once re-admissions for treatment under general anaesthetic are considered. Sensitivity analysis indicated that these findings were sensitive to assumptions in the model.

Anesthesia, General↗
PubMed2002

Effect of computerised evidence based guidelines on management of asthma and angina in adults in primary care: cluster randomised controlled trial.

OBJECTIVE: To evaluate the use of a computerised support system for decision making for implementing evidence based clinical guidelines for the management of asthma and angina in adults in primary care. DESIGN: A before and after pragmatic cluster randomised controlled trial utilising a two by two incomplete block design. SETTING: 60 general practices in north east England. PARTICIPANTS: General practitioners and practice nurses in the study practices and their patients aged 18 or over with angina or asthma. MAIN OUTCOME MEASURES: Adherence to the guidelines, based on review of case notes and patient reported generic and condition specific outcome measures. RESULTS: The computerised decision support system had no significant effect on consultation rates, process of care measures (including prescribing), or any patient reported outcomes for either condition. Levels of use of the software were low. CONCLUSIONS: No effect was found of computerised evidence based guidelines on the management of asthma or angina in adults in primary care. This was probably due to low levels of use of the software, despite the system being optimised as far as was technically possible. Even if the technical problems of producing a system that fully supports the management of chronic disease were solved, there remains the challenge of integrating the systems into clinical encounters where busy practitioners manage patients with complex, multiple conditions.

Angina Pectoris↗