Biomedical subjects

Joanne Lord

Publications and source records attributed to Joanne Lord.

5 recordsLinked to original sources

PubMed2006

Non-linearity in the cost-effectiveness frontier.

Conventional cost-effectiveness decision rules rely on the assumptions that all health care programmes are divisible and exhibit constant returns to scale for a homogeneous population; hence, the path between adjacent programmes on a cost-effectiveness frontier must be linear. In this paper we build a framework to analyse non-linear 'expansion' paths. We model the impact of two key sources of non-linearity: economies of scale or scope in the production of health care; and prioritisation of patients who are most likely to benefit from more expensive and more effective treatments. We conclude that the expansion path might be linear, convex or concave, depending on the situation. The path might also exhibit vertical discontinuity due to fixed costs or horizontal discontinuity due to indivisibility. The efficiency of resource allocation might be improved by empirical estimation of expansion paths. We discuss the advantages and disadvantages of this approach compared with a standard stratified analysis.

Cost-Benefit Analysis↗

PubMed2006

The economics of diagnosis.

Any population can be divided into two groups, one with the presence of a given disease or condition, and the other without. Diagnosis consists of using tests to sort the population into these groups. Diagnostic tests use a threshold value of a diagnostic variable to distinguish between disease-positive and disease-negative individuals. The analysis of error in diagnostic tests has typically been undertaken using receiver-operator characteristic (ROC) curves. More recently, economic value of information (VOI) methods have characterised the costs and consequences of testing. This paper develops a new method for economic test evaluation, which we call ROTS analysis. The ROTS curve plots the costs and effects of changing test thresholds, in cost-effectiveness space. We illustrate the use of our method with a worked example, and show how it can answer three key questions: (1) Is there any test that is worth doing? (2) What is a test's optimum operating point in terms of sensitivity and specificity? (3) If two tests are available, which is best? We contrast the merits of our method with those of established ROC and VOI analysis. We argue that ROTS analysis more clearly reveals the link between changing test thresholds and the cost-effectiveness of different treatments.

Cost-Benefit Analysis↗

PubMed2005

Lack of benefit of a primary care-based nurse-led education programme for people with osteoarthritis of the knee.

Osteoarthritis (OA) is the commonest cause of locomotor disability and forms a major element of the workload of the primary care team. There is evidence that patient education may improve quality of life, physical functioning, mental health and coping as well as reducing health service use. The aim of this study was to evaluate the effectiveness of a primary care-based patient education programme (PEP) using a randomised controlled trial. A cluster randomised controlled trial, involving 22 practices, was used to determine the efficacy of a nurse-led education programme. The programme consisted of a home visit and four 1-h teaching sessions. Patients were assessed at baseline and then 1, 3, 6 and 12 months post intervention using 36-item Short Form (SF-36), Western Ontario and McMaster Universities Arthritis Index (WOMAC), arthritis helplessness index and a patient knowledge questionnaire. Direct interviews were used at baseline and at the 12-month follow-up. There were no differences in depression, OA knowledge, pain or physical ability at either 1 month or 1 year between the two groups. Control practices (65 patients from 12 practices) recruited significantly fewer patients than intervention practices (105 patients from ten practices, p = 0.02). Control practices had more doctors (p = 0.02), more non-white patients (p = 0.007), fewer patients living alone (p = 0.005) and lower levels of disability (p = 0.008). We detected a lack of benefit of PEP for people with OA of the knee. This was thought to be due in part to the short intervention time employed and the heterogeneous nature of the disease and the population studied.

Cluster Analysis↗

PubMed2004

Cost-effectiveness of digital photographic screening for retinopathy of prematurity in the United Kingdom.

OBJECTIVES: To compare the cost-effectiveness of alternative methods of screening for retinopathy of prematurity (ROP) in the United Kingdom, including the existing method of indirect ophthalmoscopy by ophthalmologists and digital photographic screening by nurses. METHODS: A decision tree model was used to compare five screening modalities for the UK population of preterm babies, using a health service perspective. Data were taken from published sources, observation at a neonatal intensive care unit (NICU), and expert judgment. RESULTS: We estimated that use of standard digital cameras by nurses in NICUs would cost more than current methods (pound 371 compared with pound 321 per baby screened). However, a specialist nurse visiting units with a portable camera would be cheaper (pound 172 per baby). These estimates rely on nurses capturing and interpreting the images, with suitable training and supervision. Alternatively, nurses could capture the images then transmit them to a central unit for interpretation by ophthalmologists, although we estimate that this would be rather more expensive (pound 390 and pound 201, respectively, for NICU and visiting nurses). Sensitivity analysis was used to examine the robustness of estimates. CONCLUSIONS: It is likely that there is an opportunity to improve the efficiency of the ROP screening program. We estimate that screening by specialist nurses trained in image capture and interpretation using portable digital cameras is a cost-effective alternative to the current program of direct visualization by ophthalmologists. This option would require the development of a suitable portable machine. Direct comparative research is strongly needed to establish the accuracy of the various screening options.

Cohort Studies↗

PubMed2004

Health care resource allocation: is the threshold rule good enough?

We review the foundations of resource allocation rules based on cost-effectiveness information. Comprehensive approaches, where a total budget is allocated in one go, require estimation of the costs and effects of all available health care programmes, which is unlikely to be practical. A common alternative is to assess individual programmes against a cost-effectiveness threshold. This has been shown to be efficient if the threshold is well calibrated and all programmes can be wholly or partially implemented with constant returns to scale. We discuss the feasibility of these assumptions, and the effects of relaxing them, concluding that programme indivisibility is unlikely to be a serious problem at a national level, but that miscalibration of the threshold and non-constant returns to scale might be. A rule that avoids these difficulties has been proposed previously: a new programme should only be implemented if it can be funded by cancelling another less effective programme. This could never reduce efficiency, unlike the threshold rule, though we show that it might sometimes fail to recommend an efficiency-improving change. We suggest a refinement of this reallocation rule based on explicit estimation of the costs and effects of partial implementation of the programmes under review. Research is required to assess the practicality of this option.

Cost-Benefit Analysis↗