Measuring the value of life: Exploring a new method for deriving the monetary value of a QALY

Economic evaluations of new health technologies now typically produce an incremental cost per Quality Adjusted Life Year (QALY) value. The QALY is a measure of health benefit that combines length of life with quality of life, where quality of life is assessed on a scale where zero represents a health state equivalent to being dead and one represents full health. The challenge for decision makers, such as the Treasury, is to determine the appropriate size of the healthcare budget. Bodies such as the National Institute for Health and Clinical Excellent (NICE) in the U.K. must then determine how much they can afford to pay for a gain of one QALY, while operating under this fixed budget. While there is no fixed cost-effectiveness threshold and each intervention is assessed on a case by case basis, under normal circumstances the threshold will not be below £20,000 and not above £30,000 per QALY. Recent research has sought to determine the monetary value individuals place on a QALY to inform the size of the healthcare budget and the level of the cost-effectiveness threshold. This research has predominantly used Willingness to Pay (WTP) approaches. However, WTP has a number of known problems, most notably its insensitivity to scope. In this paper we present an alternative approach to estimating the monetary value of a QALY (MVQ), which is based upon a Time Trade Off (TTO) exercise of income with health held constant at perfect health. We present the methods and theory underlying this experimental approach and some results from an online feasibility study in the Netherlands

The impact of losses in income due to ill health: does the EQ-5D reflect lost earnings?

Two key questions in the context of UK health policy are: do the published preference indices for EQ-5D reflect the impact of lost earnings? Are we currently implicitly including indirect costs in our analyses? It is crucial to investigate whether or not individuals take into account any possible impact of lost income in health state valuation exercises. If respondents do consider income effects, and these considerations change valuations, then these effects would need to be excluded both under the current NICE reference case, or where productivity costs are included in the numerator to avoid double counting. This study adapts the study design used to generate population value sets for EQ-5D, as first used in the Measurement and Valuation of Health (MVH) Study, and carries out valuations of hypothetical EQ-5D states using Time Trade Off (TTO) exercises through an online survey administered in the Netherlands. Furthermore, this study uses a number of different TTO questions to explore the impact of losses in income on the valuation of hypothetical health states, and to determine the relationship between income and health.EQ-5D; time trade-off; health-related loss of income

FieldscapesVR: Virtual world field trips to extend and enrich field teaching

Field teaching is an indispensable feature of geoscience education, at all levels. However, delivering effective field experiences is challenging under many circumstances – not least for distance students such as Open University (OU) undergraduates. Hence, OU geoscience modules over the last 25 years have featured virtual field trips (VFTs), exploiting a range of formats, typically delivered via CD-ROM, DVD or web browser. 2013 saw a dramatic reboot with the launch of Virtual Skiddaw, a field exercise framed in a multi-user virtual environment that was created using 3D gaming software (Unity 3D). Virtual world field trips (VWFTs) offer a wealth of new opportunities for online field learning. Advances in scanning and photogrammetry make detailed observation possible, while the digital landscape and ambient audio foster immersion. Rather than merely trying to replicate an outdoor field trip, the VWFT can also go ‘beyond fieldwork’: users can access aerial perspectives; drape the digital landscape with different imagery (e.g. maps); teleport and fly to save time; call up subsurface cross-sections; even fade other avatars out if they are obscuring the view! The multi-user capability enables collaborative work, even among groups that are widely dispersed, as OU students are. There are times when a VFT can replace physical fieldwork, for example for those who cannot access the outdoor locations. However, we regard their primary role as support for physical field teaching, so that students can make the most of their, often limited, time in the field: pre-trip familiarisation and orientation, followed by post-trip revision, reflection or extension – for both educators and students; introducing basic fieldwork concepts and logistics, risk assessment, and even some fieldwork skills – for instance to students with no prior field experience – to alleviate anxiety and build confidence. For example, in Virtual Skiddaw both mapwork and compass skills can be practised in the context of a 3D landscape. VWFTs also facilitate development of spatial literacy skills by bridging the 2D/3D conceptual gap, promote active learning, foster collaborative skills and reinvigorate problem-solving exercises

Do clinicians overestimate the severity of intracerebral hemorrhage?

Background and Purpose— Intracerebral hemorrhage (ICH) has a poorer prognosis than acute ischemic stroke (AIS). However, clinician perception of prognosis may influence treatment decisions and adversely affect outcome. On acute CT, the conspicuity of ICH compared with AIS may lead clinicians to overestimate severity and influence prognostic evaluation. We investigated whether clinicians’ estimates of volume, severity, and prognosis from acute imaging differed between ICH and AIS. Methods— CT scans from participants with acute ICH or ischemic stroke were reviewed. Volume was calculated using the ABC/2 method and automated volumetric analysis via specialized imaging software. ICH cases were matched with AIS cases for lesion volume, based on acute (<6 hours) CT for ICH, and 24-hour CT for AIS. Blind to clinical information, clinicians estimated lesion volume to the nearest 5 mL, graded lesion severity from 1 (mild) to 5 (very severe), and estimated 30-day prognosis using the modified Rankin Scale. Results— We compared 33 ICH cases with 33 volume-matched AIS cases. Clinicians overestimated ICH volume and underestimated AIS volumes: mean differences (estimated−actual volume) were +8 mL (±30) for ICH and −8 mL (±27) for AIS (P<0.001). Observers rated ICH to be of greater severity and poorer prognosis compared with AIS cases: 109 of 265 (41%) ICH cases rated severity categories 4 or 5 compared with 36 of 257 (14%) AIS, P<0.001; estimated modified Rankin Scale of 0 to 2 in 125 of 265 (47%) ICH compared with 190 of 257 (74%) AIS, P<0.001. Results were unaffected by presence of intraventricular blood. Estimated severity and prognosis for ICH remained significantly worse compared with AIS after adjustment for estimated volumes. Conclusions— Clinicians overestimated ICH volume and severity compared with AIS of equivalent volume and also assigned significantly worse prognosis independent of volume estimates

Improving upon the efficiency of complete case analysis when covariates are MNAR.

Missing values in covariates of regression models are a pervasive problem in empirical research. Popular approaches for analyzing partially observed datasets include complete case analysis (CCA), multiple imputation (MI), and inverse probability weighting (IPW). In the case of missing covariate values, these methods (as typically implemented) are valid under different missingness assumptions. In particular, CCA is valid under missing not at random (MNAR) mechanisms in which missingness in a covariate depends on the value of that covariate, but is conditionally independent of outcome. In this paper, we argue that in some settings such an assumption is more plausible than the missing at random assumption underpinning most implementations of MI and IPW. When the former assumption holds, although CCA gives consistent estimates, it does not make use of all observed information. We therefore propose an augmented CCA approach which makes the same conditional independence assumption for missingness as CCA, but which improves efficiency through specification of an additional model for the probability of missingness, given the fully observed variables. The new method is evaluated using simulations and illustrated through application to data on reported alcohol consumption and blood pressure from the US National Health and Nutrition Examination Survey, in which data are likely MNAR independent of outcome

Variations in the management and survival of women under 50 years with breast cancer in the South East Thames region.

A retrospective, population-based study was undertaken to determine variations in the management of women aged less than 50 years with primary breast cancer in different hospital settings and the influence of these variations on survival. A total of 1757 women who were resident in the South East Thames Health Region aged less than 50 years at the time of diagnosis of breast cancer and who presented during a 5 year period (January 1984 to December 1988) were recorded by the Thames Cancer Registry. The hospitals at which primary surgery was undertaken were categorised as teaching or non-teaching hospitals. The non-teaching hospitals were grouped according to the mean number of patients treated annually during the study period (< or = 2, 3-9, > or = 10 each year). The following factors were compared between these groups: age, extent of disease, tumour morphology, extent of primary surgery (mastectomy vs less than mastectomy), use of axillary surgery (any vs none) and use of systemic adjuvant therapy. Survival rates for the different groups were compared. Registration rates did not differ significantly between health districts. A total of 1485 (85%) women underwent surgery in over 90 different hospitals. In 1324 (86%) of these cases the surgery was undertaken in a total of 42 NHS hospitals within SE Thames Health Region or in seven teaching hospitals in adjacent regions. Mastectomy rates decreased from 52% in 1984 to 28% in 1988 (P<0.0001), but were consistently higher in teaching hospitals (P=0.01). The use of any form of axillary surgery decreased from 49% to 36% over the 5 year period (P=0.003), with significantly lower rates of axillary surgery being performed in non-teaching hospitals (P<0.0001). The proportion of cases recorded as having non-specific morphology was higher in nonteaching than in teaching hospitals (P<0.0001). On multivariate analysis survival was significantly (P<0.001) influenced by stage and tumour histology. Among patients who underwent surgery, the type of hospital in which this was undertaken did not appear to influence survival significantly. This analysis of routine cancer registry data indicates that patients were widely dispersed in a large number of different hospitals and that there were marked variations in practice according to the type of hospital to which patients presented. The treatments provided were frequently at variance with those recommended at a consensus conference held during the study period, particularly in relation to the use of axillary surgery and adjuvant systemic therapy. The way in which services are currently provided may hamper the delivery of appropriate management and comprehensive support. These data thus have implications for the purchasing and provision of services for this common condition