Variation in the costs of healthcare for chronic disease in Australia: The case of asthma, CHERE Working Paper 2008/7

Objectives Individuals with chronic conditions represent a high healthcare cost group and understanding the cost variation among individuals is important for developing appropriate policy. This study aimed to investigate the sources of variation in the cost of healthcare for a cohort of people with asthma. It examines the costs to the health system and patient out-of-pocket costs. Methods A longitudinal observational study of asthma-related healthcare costs in a cohort of people with asthma (n=252). Participants were followed for three years using six-monthly postal surveys and individual administrative data. The factors associated with health system and patient out-of-pocket costs were investigated using generalised linear mixed models. Results There was substantial variability around the average costs of healthcare for asthma which were associated with asthma-related health measures and socio-demographic variables. The health system costs were less for those living in regional areas relative to Sydney residents and both the health system and patient out-of-pocket costs were highest in the oldest age group and lowest for children. The health system and patient out-of-pocket costs were highest for the high income group while the middle income group had the lowest total cost. Conclusions Our findings suggest that variations should be explored in developing strategies for chronic disease management and that Australia has achieved reasonable equity in access. However, out-of-pocket costs may be a deterrent for the middle income group, which should be a general concern for policies targeting the most disadvantaged group to the exclusion of concern with universal access.asthma, out-of-pocket costs, Australia

Validity of the SF-36 Health Survey as an outcome measure for trials in people with spinal cord injury

The SF-36 was interviewer-administered to 305 subjects at recruitment. Feasibility, content validity and internal consistency were assessed. We tested a priori hypotheses about discriminative, convergent and divergent validity. Interviewer-assisted administration was feasible. The content validity of several domains (Physical Function, Role Physical, Social Function and Role Emotional) was compromised by the irrelevance of some items and response options. Resultant ceiling and floor effects may limit the SF-36?s ability to detect changes over time. The SF-36 was able to discriminate differences between people with: tetraplegia versus paraplegia (in the Physical Function and Physical Composite scores); injuries that were recent ( 4 years) (in the Vitality, Social Function and Mental Health domain and Mental Composite scores), and who were employed versus unemployed (in the Physical Function, Social Function, Mental Health and Mental Composite scores). It was not able to discriminate between groups dichotomised by age, injury completeness or gender. The convergent and divergent validity of all SF-36 domains was as in other populations, except for correlations involving the Physical Function scale which were poor. Internal consistency was similar to that in other populations (Cronbach?s alpha from 0.75 to 0.92); the SF-36 has sufficient precision for population-based and clinical research in spinal cord injury. The SF-36 is useful for comparing the health status of people with spinal cord injury to that of other populations, but supplementation with a disease-specific health status measure may be necessary for trials of interventions in people with spinal cord injuries.Quality of life, outcome measures, sf-36

Validity, reliability and responsiveness of the EORTC QLQ-C30 and the EORTC QLQ-LC13 in Australians with early stage non-small cell lung cancer, CHERE Working Paper 2007/13

Aim: To assess the validity, reliability and responsiveness of two questionnaires, the QLQ-C30 and LC-13, as measures of health-related quality of life (HRQOL) in an Australian sample of people with early stage non-small cell lung cancer. Background: These two questionnaires are complementary components of the European Organisation for Research and Treatment of Cancer?s (EORTC?s) modular approach to measuring HRQOL: the QLQ-C30 is the core questionnaire, containing 30 items relevant to all cancers; the QLQ-LC13 contains 13 items specific to lung cancer. Methods: These two complementary questionnaires were assessed with data obtained from 183 participants of a randomised control trial investigating the use of Positron Emission Tomography in the management of stage I or II non-small cell lung cancer. A cohort of 173 participants, were treated by surgery and then followed for two years. Participants completed HRQOL questionnaires before the PET scan, before and after surgery, one month after surgery, and then four monthly for two years. Construct validity was tested with confirmatory factor analysis and correlation analysis was used to test for convergent/divergent validity. Discriminant validity was tested by assessing the sensitivity of the scales to the effects of moving from early to late stage disease, asymptomatic to mildly symptomatic, and to the effects of age, gender and number of comorbitities. Mean differences (standardized response means (SRM)) and effect sizes were estimated for: patients with Stage 1/11 and metastatic disease; ECOG score 0 and ECOG score 1; older and younger patients; men and women; patients with no comorbidities and those with 1 or more comorbidities. Reliability was assessed in terms of internal consistency and test-retest reliability. Responsiveness to the effects of major thoracic surgery, adjuvant radiotherapy, and disease recurrence was assessed by estimating mean differences (standardized response meansSRM?s and effect sizes for patients who underwent surgery, radiotherapy and whose disease recurred, respectively. Results: The factor structure reported previously was replicated in this sample, confirming the questionnaires? construct validity. Most scales demonstrated good to excellent internal consistency (Cronbach?s alpha range: 0.86 ? 0.94); the exceptions were the cognitive function (0.68) and nausea/vomiting scales (0.67). Test-retest reliability was generally good (intraclass correlation (ICC) range: 0.70 ? 0.81); the exceptions were the pain and nausea/vomiting scales (ICC 0.56 and 0.42). Most scales were sensitive to the large effect of moving from early to later stage disease with (SRM range: 21.3 ? 54.0; effect size range:1.14 ? 1.97 (except for emotional functioning: 13.7; 0.60)). The scales were also sensitive to small effects, detecting small to moderate differences for age (large for social functioning) and comorbidities, and small differences for moving from asymptomatic to mildly symptomatic disease, and for age. Responsiveness was also confirmed with most scales responsive to the large expected effects of surgery and disease progression ( SRM range: 21.6 ? 41.4; effect size range: 0.94 ? 1.89 (emotional functioning: 5.5; 0.19)). Conclusions: The QLQ-C30 and QLQ-LC13, when used together, provide a valid, reliable and responsive measure of HRQOL in Australians with early stage non-small cell lung cancer.Questionnaires, validity, reliability, responsiveness, QOL, lung cancer

Diaries or questionnaires for collecting self-reported healthcare utilisation and patient cost data? CHERE Project Report No 20

The literature comparing diaries and questionnaires was reviewed in order to identify the most appropriate method of collecting patient self-reported data, on health service utilisation and out-ofpocket costs, for a longitudinal study. Nine published studies met the review inclusion criteria; four compared the diary method with a self-completed questionnaire and five with an interviewer administered questionnaire. None of the eligible studies measured patient costs, and only two measured some aspects of health service utilisation. Most of the studies reported higher response rates for questionnaires than for diaries, and there was some evidence of selection bias. There was a tendency to report more symptoms, symptom intensity or health care utilisation by questionnaires compared to diaries, and compared to physician reports (included in only two studies). The review provides some information about the two approaches for collecting self-reported data, but does not provide sufficient evidence to favour either approach.diaries, health care utilisation

Men?s preferences for treatment of early stage prostate cancer: Results from a discrete choice experiment, CHERE Working Paper 2006/14

Prostate cancer is the most common cancer in men in Australia; each year over 10,000 Australians are diagnosed with this disease. There are a number of treatment options for early stage prostate cancer (ESPC); radical prostatectomy, external beam radiotherapy, brachytherapy, hormonal therapy and combined therapy. Treatment can cause serious side-effects, including severe sexual and urinary dysfunction, bowel symptoms and fatigue. Furthermore, there is no evidence as yet to demonstrate that any of these treatments confers a survival gain over active surveillance (watchful waiting). While patient preferences should be important determinants in the type of treatment offered, little is known about patients? views of the relative tolerability of side effects and of the survival gains needed to justify these. To investigate this, a discrete choice experiment (DCE) was conducted in a sample of 357 men who had been treated for ESPC and 65 age-matched controls. The sample was stratified by treatment, with approximately equal numbers in each treatment group. The DCE included nine attributes: seven side-effects and two survival attributes (duration and uncertainty). An orthogonal fractional set of 108 scenarios from the full factorial was used to generate three versions of the questionnaire, with 18 scenarios per respondent. Multinomial logit (MNL) and mixed logit (MXL) models were estimated. A random intercept MXL model provided a significantly better fit to the data than the simple MNL model, and adding random coefficients for all attributes dramatically improved model fit. Each side-effect had a statistically significant mean effect on choice, as did survival duration. Most attributes had significant variance parameters, suggesting considerable heterogeneity among respondents in their preferences. To model this heterogeneity, we included men?s health-related quality of life scores following treatment as covariates to see whether their preferences were influenced by their previous treatment experience. This study demonstrate how DCEs can be used to quantify the trade-offs patients make between side-effects and survival gains. The results provide useful insights for clinicians who manage patients with ESPC, highlighting the importance of patient preferences in treatment decisions.Prostate cancer, discrete choice experiment, preferences, quality of life

Valuing EQ-5D health states: A review and analysis, CHERE Working Paper 2007/9

Objective: To identify the key methodological issues in the construction of population-level EQ-5D / Time Trade-Off (TTO) preference elicitation studies. Study Design: This study involves three components. The first was to identify existing population-level EQ-5D TTO studies. The second was to illustrate and discuss the key areas of divergence between studies, including the international comparison of tariffs. The third was to portray the relative merits of each of the approaches, and to compare the results of studies across countries. Results: While most papers report use of the protocol developed in the original UK study, we identified three key areas of divergence in the construction and analysis of surveys. These are the number of health states valued in order to determine the algorithm for estimating all health states, the approach to valuing states worse than immediate death, and the choice of algorithm. Finally, the evidence on international comparisons suggests differences between countries, although it is difficult to disentangle differences in cultural attitudes with random error and differences due to methodological divergence. Conclusion: Differences in methods are likely to obscure true differences in values between countries. However, population-specific valuation sets for countries engaging in economic evaluation would better represent societal attitudes.health state valuation, EQ5-D