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Biomedical subjects

Aki Tsuchiya

Publications and source records attributed to Aki Tsuchiya.

18 recordsLinked to original sources

Seeing for yourself: feasibility study towards valuing visual impairment using simulation spectacles.

Elicitation of utilities from members of the public generally uses verbal description of health states. This paper reports the results of a small-scale time trade-off study on the feasibility of an alternative approach, where health states were simulated using plastic spectacles. This approach has methodological implications for the valuation exercise, in that many respondents find it difficult to conceive of visual impairment alone, without referring to their own current health. We conclude that it is feasible to simulate visual impairment in valuation exercises, but care must be taken to ensure what health state is effectively being valued.

Adolescent↗

Using rank data to estimate health state utility models.

In this paper we report the estimation of conditional logistic regression models for the Health Utilities Index Mark 2 and the SF-6D, using ordinal preference data. The results are compared to the conventional regression models estimated from standard gamble data, and to the observed mean standard gamble health state valuations. For both the HUI2 and the SF-6D, the models estimated using ordinal data are broadly comparable to the models estimated on standard gamble data and the predictive performance of these models is close to that of the standard gamble models. Our research indicates that ordinal data have the potential to provide useful insights into community health state preferences. However, important questions remain.

Health Status Indicators↗

A systematic review of the safety and effectiveness of restraint and seclusion as interventions for the short-term management of violence in adult psychiatric inpatient settings and emergency departments.

AIMS: The aim of this review was to assess whether restraint and seclusion are safe and effective interventions for the short-term management of disturbed/violent behaviour. Staff and service user perspectives on the use of these interventions were also considered. The review was undertaken as part of the development process for a national guideline on the short-term management of disturbed/violent behaviour in adult psychiatric inpatient settings and emergency departments in the United Kingdom. METHOD: An exhaustive literature search was undertaken. Systematic reviews, before and after studies, as well as qualitative studies were included. Searches were run from 1985 to 2002. FINDINGS: Thirty-six eligible studies were identified. However, none were randomised controlled trials. Most of the included studies had many limitations, such as small sample sizes, confounders not adequately accounted for, potential selection bias, poorly reported results, and lack of clarity as to whether mechanical restraints were used. This review must therefore be viewed as a mapping exercise, which illustrates the range and quality of studies that have been undertaken in this area to date. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Insufficient evidence is available to determine whether seclusion and restraint are safe and/or effective interventions for the short-term management of disturbed/violent behaviour in adult psychiatric inpatient settings. These interventions should therefore be used with caution and only as a last resort once other methods of calming a situation and/or service user have failed.

Behavior Control↗

Comparison of valuation methods used to generate the EQ-5D and the SF-6D value sets.

An interview study with 101 members of public compared the protocols used in valuation studies for EQ-5D (using ranking, visual analogue scale, and time trade-off), and SF-6D (using ranking and standard gamble). Respondents were given one of the two protocols and asked to value four states each from EQ-5D and SF-6D. VAS scores suggest the narrower range of SF-6D values is partly attributable to the descriptive system; TTO values for milder states were higher than SG values; and the mean value for EQ-5D pits using TTO and SF-6D pits using SG were closer than across the two original valuation studies.

Health Status Indicators↗

Health priorities and public preferences: the relative importance of past health experience and future health prospects.

We explore people's choices where the preference for those with worse future health prospects and the preference for the young over the old conflict. The empirical study used scenarios with four attributes: past years, past health, future years without treatment, and future health without treatment. One hundred respondents ranked various patient groups described in these terms. The results suggest a strong effect of past years: younger groups (40-year-olds) were always chosen over older ones (60-year-olds). Past health was significant in one question but not the other and future health and years without treatment were both non-significant.

Adolescent↗

QALY maximisation and people's preferences: a methodological review of the literature.

In cost-utility analysis, the numbers of quality-adjusted life years (QALYs) gained are aggregated according to the sum-ranking (or QALY maximisation) rule. This requires that the social value from health improvements is a simple product of gains in quality of life, length of life and the number of persons treated. The results from a systematic review of the literature suggest that QALY maximisation is descriptively flawed. Rather than being linear in quality and length of life, it would seem that social value diminishes in marginal increments of both. And rather than being neutral to the characteristics of people other than their propensity to generate QALYs, the social value of a health improvement seems to be higher if the person has worse lifetime health prospects and higher if that person has dependents. In addition, there is a desire to reduce inequalities in health. However, there are some uncertainties surrounding the results, particularly in relation to what might be affecting the responses, and there is the need for more studies of the general public that attempt to highlight the relative importance of various key factors.

Age Factors↗

Developing a relativities approach to valuing the prevention of non-fatal work-related accidents and ill health.

The aim of the current explorative study is to define and test a process for the valuation of the benefits associated with the prevention of non-fatal work-related accidents and ill health. A relativities approach is adopted, and monetary values for the prevention of three forms of work-related illness are estimated. The approach involves describing relevant attributes of alternative events (accidents or occurrences of ill health), their causes, the characteristics of the relevant working population, and the number of events that are avoidable, and asking respondents to make pair wise choices between alternatives options for prevention. Indirect monetary valuations are obtained against a peg event for which a reliable valuation exists (road deaths).A series of discussion groups were held to identify relevant factors affecting potential valuations and to test the presentation of information. The predicted magnitude of responses for three-case study events (and road deaths) was estimated in a pilot study. These preliminary stages informed the final survey instrument that described five attributes in addition to a statement of the event and occupation, and the likely intervention effect, which was administered by post. Based on a small sample, the results show that virtually all respondents passed the inserted consistency test. The median respondent altered their choice according to the number of events avoided for all three comparisons, such that the estimated valuations appear sensible. Potential amendments are suggested, but the general relativities approach warrants further investigation for the valuation of non-fatal work-related accidents and ill health.

Accidents, Occupational↗

A "fair innings" between the sexes: are men being treated inequitably?

In most modern developed communities, women are known to live longer than men. A less known fact is that in many statistics reporting differences in life expectancy between socio-economic classes, on average women in the worst-off social class live as long as men in the best-off social class, if not longer. It is true that women tend to have higher morbidity, or lower health-related quality of life, especially at advanced age, but this female disadvantage does not offset the life expectancy advantage sufficiently to lead to the conclusion that men and women enjoy comparable lifetime health prospects in these communities. Although there is much public and policy discussion about the inequity of health inequalities between the social classes, there is relatively little discussion about such inequalities between the sexes. The paper first discusses the applicability of the fair innings argument to the issue of inequality in health between the sexes. It critically examines six arguments concerning why inequality in health between the sexes may or may not be an inequity. Next, special attention is given to the argument that it is wrong to judge the fairness or unfairness of health inequalities in isolation, but that this judgement should be made only after considering other inequalities relevant to overall human well-being, many of which are believed to work to the disadvantage of women. An analytical framework based on the Gender-related Development Index (a supplementary index to the Human Development Index) is taken as a starting point, to address the issue of health and overall well-being. But this is found wanting, and suggestions are made as to how its conceptual and empirical properties could be improved. Meanwhile we conclude that a prima facie case has been made that the current distribution of health in most countries does not give men a "fair innings", but the broader question about general well-being remains unresolved.

Attitude to Health↗

Procedural justice in public health care resource allocation.

INTRODUCTION: The legal studies literature on procedural justice identifies six key characteristics of procedural justice: accuracy, consistency, impartiality, reversibility, transparency and voice. However, the relative importance of these in the context of public health care resource allocation is unclear, as is whether they are valuable instrumentally (because it contributes to better outcomes) or inherently (for its own sake). METHODS: A survey of 80-odd members of the UK public determined the following: the ranking of all the six characteristics; the pairwise comparisons of the characteristics; and whether each characteristic was important for instrumental reasons, for intrinsic reasons or for both. RESULTS: Respondents ranked the procedures in the order of accuracy, consistency, impartiality, reversibility and transparency. Procedural justice was valued for both instrumental and inherent reasons. DISCUSSION/CONCLUSION: A robust ranking of five of the six procedural characteristics was found. The ranking for voice was sensitive to the question format, which has methodological implications. Around a quarter to a third of respondents regarded a procedural characteristic to have entirely intrinsic value.

Adolescent↗

A comparison of the EQ-5D and SF-6D across seven patient groups.

As the number of preference-based instruments grows, it becomes increasingly important to compare different preference-based measures of health in order to inform an important debate on the choice of instrument. This paper presents a comparison of two of them, the EQ-5D and the SF-6D (recently developed from the SF-36) across seven patient/population groups (chronic obstructive airways disease, osteoarthritis, irritable bowel syndrome, lower back pain, leg ulcers, post menopausal women and elderly). The mean SF-6D index value was found to exceed the EQ-5D by 0.045 and the intraclass correlation coefficient between them was 0.51. Whilst this convergence lends some support for the validity of these measures, the modest difference at the aggregate level masks more significant differences in agreement across the patient groups and over severity of illness, with the SF-6D having a smaller range and lower variance in values. There is evidence for floor effects in the SF-6D and ceiling effects in the EQ-5D. These discrepancies arise from differences in their health state classifications and the methods used to value them. Further research is required to fully understand the respective roles of the descriptive systems and the valuation methods and to examine the implications for estimates of the impact of health care interventions.

Activities of Daily Living↗

Exploring social welfare functions and violation of monotonicity: an example from inequalities in health.

The social welfare function (SWF) has been used within the economics literature, to study trade-offs between equality and efficiency. These SWFs are characterised by properties determined by traditional welfare economics. One of these properties, the monotonicity principle is explored in this paper. In the context of health there may be occasions when the monotonicity principle is violated as there may be circumstances where distributional issues dominate efficiency concerns. When this is the case, conventional SWFs are not flexible enough to represent such social preferences. Therefore, we propose a SWF with an alternative specification, which is general enough to accommodate preferences that are not necessarily monotonic. A survey of the Spanish general public was undertaken to estimate preferences regarding equality in health, relative to efficiency in health. The results (with 973 usable responses) give strong support to the existence of public preferences which violate the monotonicity principle, and thus to the usefulness of the alternative specification proposed here.

Attitude to Health↗

The person trade-off method and the transitivity principle: an example from preferences over age weighting.

The person trade-off (PTO) is increasingly being used to elicit preferences in health. This paper explores the measurement properties of the PTO method in the context of a study about how members of the public prioritise between patients of different ages. In particular, it considers whether PTO responses satisfy the transitivity principle; that is, whether one PTO response can be inferred from two other PTO responses. The results suggest that very few responses to PTO questions satisfy cardinal transitivity condition. However, this study has produced results that suggest that cardinal transitivity will hold, on average, when respondents who fail to satisfy the ordinal transitivity condition have been excluded from the analysis. This suggests that future PTO studies should build in checks for ordinal transitivity.

Adult↗

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↗

Measuring people's preferences regarding ageism in health: some methodological issues and some fresh evidence.

In this paper, we outline the three main concepts of 'ageism'; health maximisation ageism, productivity ageism, and fair innings ageism. We provide a methodological overview of the existing empirical literature on people's preferences regarding age and classify these studies according to the types of questions that have been asked. We consider some of the methodological issues involved in eliciting preferences regarding ageism and propose using a fixed duration of benefit rather than, as some studies have done, a benefit that lasts for a full lifetime. Informed by this discussion, we present the results from our own empirical study, carried out in the UK, which combines qualitative and quantitative methods to explore the reasons people have for choosing one age over another. In so doing, we are able to consider the extent to which respondents might bring extraneous factors to bear on their responses and/or disregard relevant information (such as that relating to the fixed nature of the benefit). The results suggest that people are broadly in favour of giving priority to younger over older people, based on arguments relating to both productivity ageism and fair innings ageism. However, respondents appear to assume that a benefit would last for a full lifetime (even if they are told to assume a fixed benefit), unless they are asked to consider a 'full-life' benefit first. This particular framing effect has important implications for preference elicitation studies, suggesting that if you want people to answer the question you have in mind, first ask them the question you think they may have in mind.

Adolescent↗

Estimating an EQ-5D population value set: the case of Japan.

Quality adjustment weights for quality-adjusted life years (QALYs) are available with the EQ-5D Instrument, which are based on a survey that quantified the preferences of the British public. However, the extent to which this British value set is applicable to other, especially non-European, countries is yet unclear. The objectives of this study are (a) to compare the valuations obtained in Japan and Britain, and (b) to explore a local Japanese value set. A diminished study design is employed, where 17 hypothetical EQ-5D health states are evaluated as opposed to 42 in the British study. The official Japanese version of the instrument and the Time Trade-Off method are used to interview 543 members of the public. The results are: firstly, the evaluations obtained in Japan and those from Britain differ by 0.24 on average on a [-1, +1] scale, and mean absolute error (MAE) in predicting the Japanese preferences with the British value set is 0.23. Secondly, comparable regressions suggest that the two peoples have systematically different preference structures (p<0.001 for 8 of 12 coefficients; F-test). Thirdly, using alternative models, the predictions are improved so that the local Japanese value set achieves MAE in the order of 0.01.

Attitude to Health↗

The QALY model and individual preferences for health states and health profiles over time: a systematic review of the literature.

The numbers of quality-adjusted life years (QALYs) gained are increasingly being used to represent the gains in individual utility from treatment. This requires that the value of a health improvement to an individual is a simple product of gains in quality of life and length of life. The article reports on a systematic review of the literature on 2 issues: whether the value of a state is affected by how long the state lasts, and by states that come before or after it. It was found that individual preferences over health are influenced by the duration of health states and their sequence. However, although there is much variation across individual respondents, the assumptions tend to hold much better when valuations are aggregated across respondents, which is encouraging for economic evaluations that rely on using average (mean or median) values.

Empirical Research↗