Cognitive Overload? An Exploration of the Potential Impact of Cognitive Functioning in Discrete Choice Experiments with Older People in Health Care

ObjectivesThis exploratory study sought to investigate the effect of cognitive functioning on the consistency of individual responses to a discrete choice experiment (DCE) study conducted exclusively with older people.MethodsA DCE to investigate preferences for multidisciplinary rehabilitation was administered to a consenting sample of older patients (aged 65 years and older) after surgery to repair a fractured hip (N = 84). Conditional logit, mixed logit, heteroscedastic conditional logit, and generalized multinomial logit regression models were used to analyze the DCE data and to explore the relationship between the level of cognitive functioning (specifically the absence or presence of mild cognitive impairment as assessed by the Mini-Mental State Examination) and preference and scale heterogeneity.ResultsBoth the heteroscedastic conditional logit and generalized multinomial logit models indicated that the presence of mild cognitive impairment did not have a significant effect on the consistency of responses to the DCE.ConclusionsThis study provides important preliminary evidence relating to the effect of mild cognitive impairment on DCE responses for older people. It is important that further research be conducted in larger samples and more diverse populations to further substantiate the findings from this exploratory study and to assess the practicality and validity of the DCE approach with populations of older people.     

Assessing the construct validity of the Quality-of-Life-Aged Care Consumers (QOL-ACC): an aged care-specific quality-of-life measure

Quality of Life Research - To evaluate the construct (convergent and known group) validity of the Quality-of-Life-Aged Care Consumer (QOL-ACC), an older-person-specific quality-of-life measure...     

Does one size fit all? Assessing the preferences of older and younger people for attributes of quality of life

Purpose

To systematically compare, via ranking and best worst tasks, the relative importance of key dimensions of quality of life for younger and older people.

Methods

A web-based survey was developed for administration to two Australia-wide community-based samples comprising younger people aged 18–64 years and older people aged 65 years and above. Respondents were asked to rank 12 quality of life dimensions. Respondents also completed a successive best worst task using the same 12 quality of life dimensions.

Results

The relative importance of the quality of life dimensions differed for younger and older person samples. For older people, the ability to be independent and to have control over their daily lives were particularly important for their overall quality of life whereas for younger people, mental health was considered most important.

Conclusions

Many interventions accessed by older people in geriatric medicine and aged care sectors have a broader impact upon quality of life beyond health status. The findings from this study indicate that a focus on broader aspects of quality of life may also be consistent with the preferences of older people themselves as to what constitutes quality of life from their perspective.

     

Deriving welfare measures from discrete choice experiments: a response to Ryan and Santos Silva

In this response we start by highlighting the key area of agreement between the commentaries and our original paper: if there is uncertainty regarding which alternative will be chosen, in a DCE or in the real world, then the compensating variation as modified for discrete data by Small and Rosen is the appropriate method of deriving welfare measures from DCEs. Both commentators point out circumstances in which the method traditionally used in the health economics arena may be consistent with the compensating variation. We show that these circumstances require a number of potentially unrealistic and ad hoc assumptions, and argue that using the traditional method could produce erroneous welfare estimates if these assumptions fail to hold in practice. We show that the compensating variation method can accommodate each of the special cases raised by the commentators and therefore is the more general and appropriate approach to deriving welfare measures from DCEs. We also respond to issues raised regarding the estimation of DCEs in general and our application to asthma medication in particular. Copyright © 2004 John Wiley & Sons, Ltd.     

Deriving distributional weights for QALYs through discrete choice experiments

This paper presents the first attempt to use a discrete choice experiment to derive distributional weights for quality adjusted life years (QALYs), based on characteristics (age and severity) of the beneficiaries. A novel approach using the Hicksian compensating variation is applied. Advantages include derivation of weights for QALYs, not just for life or life years saved, and investigation of the impact of the size of the health gain by allowing the gain to be traded against other characteristics. Results suggest one would generally not weight QALYs, except in a small number of specific cases and in those cases the weights are relatively small. Methodological challenges are highlighted as is a future research agenda.     

Patient preferences for managing asthma: results from a discrete choice experiment

Effective control of asthma requires regular preventive medication. Poor medication adherence suggests that patient preferences for medications may differ from the concerns of the prescribing clinicians. This study investigated patient preferences for preventive medications across symptom control, daily activities, medication side-effects, convenience and costs, using a discrete choice experiment embedded in a randomized clinical trial involving patients with mild-moderate persistent asthma. The present data were collected after patients had received 6 weeks' treatment with one of two drugs. Three choice options were presented, to continue with the current drug, to change to an alternative, hypothetical drug, or to take no preventive medication. Analysis used random parameter multinomial logit. Most respondents chose to continue with their current drug in most choice situations but this tendency differed depending on which medication they had been allocated. Respondents valued their ability to participate in usual daily activities and sport, preferred minimal symptoms, and were less likely to choose drugs with side-effects. Cost was also significant, but other convenience attributes were not. Demographic characteristics did not improve the model fit. This study illustrates how discrete choice experiments may be embedded in a clinical trial to provide insights into patient preferences.     

Investigating business outcomes of healthy food retail strategies: A systematic scoping review

Large changes to food retail settings are required to improve population diet. However, limited research has comprehensively considered the business implications of healthy food retail strategies for food retailers. We performed a systematic scoping review to identify types of business outcomes that have been reported in healthy food retail strategy evaluations. Peer‐reviewed and grey literature were searched. We identified qualitative or quantitative real‐world food or beverage retail strategies designed to improve the healthiness of the consumer nutrition environment (eg, changes to the “marketing mix” of product, price, promotion, and/or placement). Eligible studies reported store‐ or chain‐level outcomes for measures of commercial viability, retailer perspectives, customer perspectives, and/or community outcomes. 11 682 titles and abstracts were screened with 107 studies included for review from 15 countries. Overall item sales, revenue, store patronage, and customer level of satisfaction with strategy were the most frequently examined outcomes. There was a large heterogeneity in outcome measures reported and in favourability for retailers of outcomes across studies. We recommend more consistent reporting of business outcomes and increased development and use of validated and reliable measurement tools. This may help generate more robust research evidence to aid retailers and policymakers to select feasible and sustainable healthy food retail strategies to benefit population health within and across countries.     

The individual and health sector costs of asthma: the first year of a longitudinal study in New South Wales

OBJECTIVE: To identify the resources used and the costs incurred by people with asthma for health care and non-health care products and services to manage asthma. METHODS: A prospective, longitudinal study, using self-reported and administrative data, commenced in 2001 in New South Wales (NSW). Data sources included two six-monthly surveys, hospital admission data from NSW Health, and pharmaceutical benefits and Medicare data. A cohort of 245 people with asthma, aged between 5-75 years, was recruited from the general population and from hospital emergency departments. The study measured the use and cost of health care services and products, including alternative therapies and home modifications. Costs to both the health care system and individuals were measured. RESULTS: General practitioner visits and asthma medications were the items of health care most commonly used. Medications were also the largest component of individual costs for health care in terms of the average payment and the number of people facing an out-of-pocket cost, although home equipment and modifications were the most expensive individual items. The distribution of individual costs was highly skewed, ranging from dollar 0 to dollar 4,882 per person per annum (median dollar 89). Admitted hospital care was the largest component of the cost to the health care system. CONCLUSION: While individual costs were not large for the majority, some people faced substantial costs, with the highest of these being for non-health care items. Implications: Asthma management policies may need to incorporate schemes to alleviate the impact of costs for the minority experiencing significant out-of-pocket expenses.     

Deleting ‘irrational’ responses from discrete choice experiments: a case of investigating or imposing preferences?

Investigation of the 'rationality' of responses to discrete choice experiments (DCEs) has been a theme of research in health economics. Responses have been deleted from DCEs where they have been deemed by researchers to (a) be 'irrational', defined by such studies as failing tests for non-satiation, or (b) represent lexicographic preferences. This paper outlines a number of reasons why deleting responses from DCEs may be inappropriate after first reviewing the theory underpinning rationality, highlighting that the importance placed on rationality depends on the approach to consumer theory to which one ascribes. The aim of this paper is not to suggest that all preferences elicited via DCEs are rational. Instead, it is to suggest a number of reasons why it may not be the case that all preferences labelled as 'irrational' are indeed so. Hence, deleting responses may result in the removal of valid preferences; induce sample selection bias; and reduce the statistical efficiency and power of the estimated choice models. Further, evidence suggests random utility theory may be able to cope with such preferences. Finally, we discuss a number of implications for the design, implementation and interpretation of DCEs and recommend caution regarding the deletion of preferences from stated preference experiments.