Adjusting for cross-cultural differences in computer-adaptive tests of quality of life.

PURPOSE: Previous studies using the WHOQOL measures have demonstrated that the relationship between individual items and the underlying quality of life (QoL) construct may differ between cultures. If unaccounted for, these differing relationships can lead to measurement bias which, in turn, can undermine the reliability of results. METHODS: We used item response theory (IRT) to assess differential item functioning (DIF) in WHOQOL data from diverse language versions collected in UK, Zimbabwe, Russia, and India (total N = 1332). Data were fitted to the partial credit 'Rasch' model. We used four item banks previously derived from the WHOQOL-100 measure, which provided excellent measurement for physical, psychological, social, and environmental quality of life domains (40 items overall). Cross-cultural differential item functioning was assessed using analysis of variance for item residuals and post hoc Tukey tests. Simulated computer-adaptive tests (CATs) were conducted to assess the efficiency and precision of the four items banks. RESULTS: Splitting item parameters by DIF results in four linked item banks without DIF or other breaches of IRT model assumptions. Simulated CATs were more precise and efficient than longer paper-based alternatives. DISCUSSION: Assessing differential item functioning using item response theory can identify measurement invariance between cultures which, if uncontrolled, may undermine accurate comparisons in computer-adaptive testing assessments of QoL. We demonstrate how compensating for DIF using item anchoring allowed data from all four countries to be compared on a common metric, thus facilitating assessments which were both sensitive to cultural nuance and comparable between countries

The development and validation of a general measure of well-being: the BBC well-being scale

Purpose: The concept of maximising well-being, as opposed to merely treating mental disorder, is a powerful current theme in the area of mental health. Clearly this emphasises the need for appropriate valid and reliable measures of general well-being. This paper examines the appropriateness of a number of measures in this area and concludes that existing assessment tools fail to address the full range of aspects of personal well-being. This paper therefore presents the psychometric properties, validity and reliability of a new measure of well-being-the BBC Well-being Scale. Methods: A total of 1,940 participants completed the new measure, the Goldberg scales of anxiety and depression, the 'List of Threatening Experiences' life events scale, a modified version of the Response Styles Questionnaire and a modified version of the Internal, Personal and Situational Attributions Questionnaire presented via the internet. Results: Exploratory factor-analysis suggested a three-factor solution including themes of psychological well-being, physical health and well-being and relationships. The total 24-item scale had good internal consistency (α = .935) and correlated significantly with key demographic variables and measures of concurrent validity. Conclusions: The new measure-the BBC Well-being Scale-is recommended for research and clinical purposes. © 2011 Springer Science+Business Media B.V

Assessing health and well-being among older people in rural South Africa

Background: The population in developing countries is ageing, which is likely to increase the burden of noncommunicable diseases and disability. Objective: To describe factors associated with self-reported health, disability and quality of life (QoL) of older people in the rural northeast of South Africa. Design: Cross-sectional survey of 6,206 individuals aged 50 and over. We used multivariate analysis to examine relationships between demographic variables and measures of self-reported health (Health Status), functional ability (WHODASi) and quality of life (WHOQoL). Results: About 4,085 of 6,206 people eligible (65.8%) completed the interview. Women (Odds Ratio (OR) 1.30, 95% CI 1.09, 1.55), older age (OR2.59, 95% CI 1.97, 3.40), lower education (OR1.62, 95% CI 1.31,2.00), single status (OR1.18, 95% CI 1.01, 1.37) and not working at present (OR1.29, 95% CI 1.06, 1.59) were associated with a low health status. Women were also more likely to report a higher level of disability (OR1.38, 95% CI 1.14, 1.66), as were older people (OR2.92, 95% CI 2.25, 3.78), those with no education (OR1.57, 95% CI 1.26, 1.97), with single status (OR1.25, 95% CI 1.06, 1.46) and not working at present (OR1.33, 95% CI 1.06, 1.66). Older age (OR1.35, 95% CI 1.06, 1.74), no education (OR1.39, 95% CI 1.11, 1.73), single status (OR1.28, 95% CI 1.10, 1.49), a low household asset score (OR1.52, 95% CI 1.19, 1.94) and not working at present (OR1.32; 95% CI 1.07, 1.64) were all associated with lower quality of life. Conclusions: This study presents the first population-based data from South Africa on health status, functional ability and quality of life among older people. Health and social services will need to be restructured to provide effective care for older people living in rural South Africa with impaired functionality and other health problems

Predictors of quality of life ratings from persons with dementia: the role of insight

Objective: Evidence suggests that people with dementia are able to respond accurately and consistently to questions about quality of life (QoL), although large discrepancies exist between patient and proxy ratings. This may be due, in part, to the reduced insight of the person with dementia. The aim of this study was to explore the predictors of QoL ratings in a sample of people with mild dementia, with a particular focus on the role of insight. Methods: Sixty-nine participants and their caregivers were recruited from a memory clinic setting. The Bath Assessment of Subjective Quality of Life in Dementia (BASQID), Alzheimer’s Disease-Related Quality of Life Scale, Memory Functioning Scale, Alzheimer's Disease Cooperative Study Activities of Daily Living (ADL) Inventory and Mini Mental Status Examination were administered. Results: Regression analyses indicated that the strongest predictor of QoL ratings from persons with dementia was their awareness of memory function, such that lower awareness was associated with higher QoL ratings. Proxy ratings of activity performance and enjoyment of activity were also significant predictors of BASQID scores. Conclusions: Awareness of memory function impacts directly on patient QoL ratings and can also mask the effects of changes in other outcomes such as ADL function. Measures of awareness should therefore be employed alongside patient QoL ratings in order to ensure they are interpreted accurately. Discrepancies between patient and proxy QoL ratings do not necessarily occur because of patient unreliability, but may instead reflect the application of distinct modes of QoL assessment that emphasise very different outcomes

The Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE): study protocol for a cluster randomised controlled trial

Introduction People with type 1 diabetes (T1DM) require insulin therapy to sustain life, and need optimal glycaemic control to prevent diabetic ketoacidosis and serious long-term complications. Insulin is generally administered using multiple daily injections but can also be delivered using an infusion pump (continuous subcutaneous insulin infusion), a more costly option with benefits for some patients. The UK National Institute for Health and Care Excellence (NICE) recommend the use of pumps for patients with the greatest need, citing insufficient evidence to approve extension to a wider population. Far fewer UK adults use pumps than in comparable countries. Previous trials of pump therapy have been small and of short duration and failed to control for training in insulin adjustment. This paper describes the protocol for a large randomised controlled trial comparing pump therapy with multiple daily injections, where both groups are provided with high-quality structured education. Methods and analysis A multicentre, parallel group, cluster randomised controlled trial among 280 adults with T1DM. All participants attended the week-long dose adjustment for normal eating (DAFNE) structured education course, and receive either multiple daily injections or pump therapy for 2 years. The trial incorporates a detailed mixed-methods psychosocial evaluation and cost-effectiveness analysis. The primary outcome will be the change in glycosylated haemoglobin (HbA1c) at 24 months in those participants whose baseline HbA1c is at or above 7.5% (58 mmol/mol). The key secondary outcome will be the proportion of participants reaching the NICE target of an HbA1c of 7.5% (58 mmol/mol) or less at 24 months. Ethics and dissemination The protocol was approved by the Research Ethics Committee North West, Liverpool East and received Medicines and Healthcare products Regulatory Agency (MHRA) clinical trials authorisation. Each participating centre gave National Health Service R&D approval. We shall disseminate study findings to study participants and through peer reviewed publications and conference presentations, including lay user groups. Trial registration number ISRCTN 61215213

How is subjective well-being related to quality of life? Do we need two concepts and both measures?

Subjective well-being (SWB) and subjective quality of life (QoL) are key concepts describing experience, capacities, states, behaviours, appraisals, and emotional reactions to circumstances. Used widely in public discourse, policy, and research, their theoretical and empirical relations remain little explored. The present research aimed to develop an integrated model of SWB and QoL through empirically testing its overlapping and exclusive dimensions. Survey data was obtained from N = 2533 in 11 countries. Adults completed the WHOQOL Spirituality, Religion and Personal Beliefs (SRPB) instrument which assesses 33 QoL facets in 6 domains. The facets operationalize components of the hedonic SWB model, extended with eudaimonia, as SWB+. Network analyses, and regression models with random effect for cultural centre, assessed the differential contributions of SWB+ and QoL in predicting general QoL, explanatory power, and model parsimony. When all SWB+ and QoL variables are assessed together, the final model explains more variance in general QoL than either of the competing models; also it shows the most parsimonious fit. This fully integrated model contains only positive feelings from SWB+, with 13 other QoL facets drawn from all six domains, when adjusted for health status and educational level. These findings provide the foundation for a new Life Quality and Well-being (LQW) model that awaits confirmation. The LQW model improves on existing models of SWB+ and QoL by better explaining general QoL than facets of either model on its own. The 14 selected facets potentially offer a new, single measure with considerable conceptual breadth, and international foundations.</p

How do Zimbabweans value health states?

Background Quality of life weights based on valuations of health states are often used in cost utility analysis and population health measures. This paper reports on an attempt to develop quality of life weights within the Zimbabwe context. Methods 2,384 residents in randomly selected small residential plots of land in a high-density suburb of Harare valued descriptors of 38 health states based on different combinations of the five domains of the EQ-5D (mobility, self-care, usual activities, pain or discomfort and anxiety or depression). The English version of the EQ-5D was used. The time trade-off method was used to determine the values, and 19,020 individual preferences for health states were analysed. A residual maximum likelihood linear mixed model was used to estimate a function for predicting the values of all possible combinations of levels on the five domains. The model was fit to a random subset of two-thirds of the observations, with the remaining observations reserved for analysis of predictive validity. The results were compared to a similar study undertaken in the United Kingdom. Results A credible model was developed to predict the values of states that were not valued directly. In the subset of observations reserved for validation, the mean absolute difference between predicted and observed values was 0.045. All domains of the EQ-5D were found to contribute significantly to the model, both at the moderate and severe levels. Severe pain was found to have the largest negative coefficient, followed by the inability to wash and dress oneself. Conclusion Despite a generally lower education level than their European counterparts, urban Zimbabweans appear to value health states in a consistent manner, and the determination of a global method of establishing quality of life weights may be feasible and valid. However, as the relative weightings of the different domains, although correlated, differed from the standard set of weights recommended by the EuroQol Group, the locally determined coefficients should be used within the Zimbabwean context

Study protocol: developing a decision system for inclusive housing: applying a systematic, mixed-method quasi-experimental design

Background Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. Methods/Design This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. Discussion It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing preferences into commercial decisions. Housing designers and developers will benefit from the creation of a parsimonious set of consumer-led housing preferences by which to make informed investments in future housing and contribute to future housing policy. The research design has not been applied in the Australian research context or elsewhere, and will provide a much needed blueprint for market investment to develop viable, consumer directed inclusive housing options for people with complex disability

A falls prevention programme to improve quality of life, physical function and falls efficacy in older people receiving home help services: study protocol for a randomised controlled trial

BACKGROUND: Falls and fall-related injuries in older adults are associated with great burdens, both for the individuals, the health care system and the society. Previous research has shown evidence for the efficiency of exercise as falls prevention. An understudied group are older adults receiving home help services, and the effect of a falls prevention programme on health-related quality of life is unclear. The primary aim of this randomised controlled trial is to examine the effect of a falls prevention programme on quality of life, physical function and falls efficacy in older adults receiving home help services. A secondary aim is to explore the mediating factors between falls prevention and health-related quality of life. METHODS: The study is a single-blinded randomised controlled trial. Participants are older adults, aged 67 or older, receiving home help services, who are able to walk with or without walking aids, who have experienced at least one fall during the last 12 months and who have a Mini Mental State Examination of 23 or above. The intervention group receives a programme, based on the Otago Exercise Programme, lasting 12 weeks including home visits and motivational telephone calls. The control group receives usual care. The primary outcome is health-related quality of life (SF-36). Secondary outcomes are leg strength, balance, walking speed, walking habits, activities of daily living, nutritional status and falls efficacy. All measurements are performed at baseline, following intervention at 3 months and at 6 months' follow-up. Sample size, based on the primary outcome, is set to 150 participants randomised into the two arms, including an estimated 15-20% drop out. Participants are recruited from six municipalities in Norway. DISCUSSION: This trial will generate new knowledge on the effects of an exercise falls prevention programme among older fallers receiving home help services. This knowledge will be useful for clinicians, for health managers in the primary health care service and for policy makers