The cost-effectiveness of changes to the care pathway used to identify depression and provide treatment amongst people with diabetes in England: a model-based economic evaluation.

BACKGROUND: Diabetes is associated with premature death and a number of serious complications. The presence of comorbid depression makes these outcomes more likely and results in increased healthcare costs. The aim of this work was to assess the health economic outcomes associated with having both diabetes and depression, and assess the cost-effectiveness of potential policy changes to improve the care pathway: improved opportunistic screening for depression, collaborative care for depression treatment, and the combination of both. METHODS: A mathematical model of the care pathways experienced by people diagnosed with type-2 diabetes in England was developed. Both an NHS perspective and wider social benefits were considered. Evidence was taken from the published literature, identified via scoping and targeted searches. RESULTS: Compared with current practice, all three policies reduced both the time spent with depression and the number of diabetes-related complications experienced. The policies were associated with an improvement in quality of life, but with an increase in health care costs. In an incremental analysis, collaborative care dominated improved opportunistic screening. The incremental cost-effectiveness ratio (ICER) for collaborative care compared with current practice was £10,798 per QALY. Compared to collaborative care, the combined policy had an ICER of £68,017 per QALY. CONCLUSIONS: Policies targeted at identifying and treating depression early in patients with diabetes may lead to reductions in diabetes related complications and depression, which in turn increase life expectancy and improve health-related quality of life. Implementing collaborative care was cost-effective based on current national guidance in England.

QLU-C10D: a health state classification system for a multi-attribute utility measure based on the EORTC QLQ-C30.

PURPOSE: To derive a health state classification system (HSCS) from the cancer-specific quality of life questionnaire, the EORTC QLQ-C30, as the basis for a multi-attribute utility instrument. METHODS: The conceptual model for the HSCS was based on the established domain structure of the QLQ-C30. Several criteria were considered to select a subset of dimensions and items for the HSCS. Expert opinion and patient input informed a priori selection of key dimensions. Psychometric criteria were assessed via secondary analysis of a pooled dataset comprising HRQOL and clinical data from 2616 patients from eight countries and a range of primary cancer sites, disease stages, and treatments. We used confirmatory factor analysis (CFA) to assess the conceptual model's robustness and generalisability. We assessed item floor effects (>75 % observations at lowest score), disordered item response thresholds, coverage of the latent variable and differential item function using Rasch analysis. We calculated effect sizes for known group comparisons based on disease stage and responsiveness to change. Seventy-nine cancer patients assessed the relative importance of items within dimensions. RESULTS: CFA supported the conceptual model and its generalisability across primary cancer sites. After considering all criteria, 12 items were selected representing 10 dimensions: physical functioning (mobility), role functioning, social functioning, emotional functioning, pain, fatigue, sleep, appetite, nausea, bowel problems. CONCLUSIONS: The HSCS created from QLQ-C30 items is known as the EORTC Quality of Life Utility Measure-Core 10 dimensions (QLU-C10D). The next phase of the QLU-C10D's development involves valuation studies, currently planned or being conducted across the globe.

Using a discrete choice experiment to value the QLU-C10D: feasibility and sensitivity to presentation format.

PURPOSE: To assess the feasibility of using a discrete choice experiment (DCE) to value health states within the QLU-C10D, a utility instrument derived from the QLQ-C30, and to assess clarity, difficulty, and respondent preference between two presentation formats. METHODS: We ran a DCE valuation task in an online panel (N = 430). Respondents answered 16 choice pairs; in half of these, differences between dimensions were highlighted, and in the remainder, common dimensions were described in text and differing attributes were tabulated. To simplify the cognitive task, only four of the QLU-C10D's ten dimensions differed per choice set. We assessed difficulty and clarity of the valuation task with Likert-type scales, and respondents were asked which format they preferred. We analysed the DCE data by format with a conditional logit model and used Chi-squared tests to compare other responses by format. Semi-structured telephone interviews (N = 8) explored respondents' cognitive approaches to the valuation task. RESULTS: Four hundred and forty-nine individuals were recruited, 430 completed at least one choice set, and 422/449 (94 %) completed all 16 choice sets. Interviews revealed that respondents found ten domains difficult but manageable, many adopting simplifying heuristics. Results for clarity and difficulty were identical between formats, but the "highlight" format was preferred by 68 % of respondents. Conditional logit parameter estimates were monotonic within domains, suggesting respondents were able to complete the DCE sensibly, yielding valid results. CONCLUSION: A DCE valuation task in which only four of the QLU-C10D's ten dimensions differed in any choice set is feasible for deriving utility weights for the QLU-C10D.

Mapping from disease-specific to generic health-related quality-of-life scales: a common factor model.

OBJECTIVES: To develop a coherent method for estimating mappings between treatment effects on disease-specific measurement (DSM) instruments and generic health-related quality-of-life (QOL) measures, when both are subject to measurement errors. METHODS: We identified three properties that must be satisfied for mappings to be logically coherent: invertability, transitivity, and invariance to linear transformation. Of the common regressions, ordinary least squares (OLS), geometric mean (GM), and orthogonal regression, only GM has all these properties, and then only in special cases. We developed a common factor model of how DSM and generic QOL scales are related, and derived expressions for coherent mapping coefficients. We showed that these are equivalent to adjusted forms of OLS or GM regressions. Where cohort data are available on just one DSM and one QOL measure, external data on the reproducibility of the DSM are required. In some circumstances, the mappings can be estimated without external data. We illustrated the estimation of mapping coefficients by using data on EuroQol five-dimensional (EQ-5D) questionnaire, 12-item short form health survey (SF-12) Mental Component Summary, and the Beck Depression Inventory (BDI), from a trial of treatments for depression. RESULTS: OLS underestimates and GM overestimates mappings from DSMs to generic QOL measures. Mappings estimated by using external data on reliability were similar to those estimated by using internal data, suggesting approximate adequacy of the common factor model. CONCLUSIONS: Neither OLS nor GM regression, unless corrected, is suitable for estimating mappings between disease-specific and generic QOL scales. OLS systematically underestimates mappings, but it can be adjusted by using external information on test-retest reliability.

Developing and testing methods for deriving preference-based measures of health from condition-specific measures (and other patient-based measures of outcome).

OBJECTIVES: Generic preference-based measures such as EQ-5D are widely used to estimate quality-adjusted life-years but may not be available or, more importantly, appropriate in some medical conditions. Condition-specific preference-based measures (CSPBMs) provide an alternative to generic measures that may be more relevant in some conditions. This project conducted five studies to examine issues in the development and use of CSPBMS: (1) literature review of measures; (2) deriving health states values for classifications with highly correlated dimensions; (3) impact of condition labelling; (4) impact of add-on dimensions; and (5) comparative performance of measures. DESIGN: (1) Systematic search and literature review; (2) and (5) psychometric analyses on existing data; (2), (3) and (4) valuation surveys and survey analyses. SETTING: Valuation surveys conducted using face-to-face interviews in the respondents' homes. PARTICIPANTS: Valuation surveys conducted using representative samples of the UK general population. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The project developed a CSPBM CORE-6D and analyses AQL-5D, CORE-6D, EORTC-8D, EQ-5D, OAB-5D and SF-6D data. RESULTS: (1) There was substantial variability in methods used to develop CSPBMs. (2) A new method for generating states using Rasch analysis was undertaken, which successfully dealt with the problem of highly correlated domains. (3) Condition labels affected utility values but this was dependent on the condition and severity of the health state. (4) Adding on an extra dimension affected health-state values and preference weights for other dimensions. (5) The performance of CSPBMs was comparable with that of their parent instrument and of generic preference-based measures with better performance for discrimination between severity groups. CONCLUSIONS: CSPBMs have an important role for economic evaluation, for which generic measures are inappropriate. However, their use in economic evaluation may be compromised by naming the condition; the exclusion of side effects and comorbidities; and focusing effects. Whether a reduction in comparability should be accepted depends on the extent of any gain in validity and responsiveness. This will depend on the condition and measure in question. Research agenda: (1) The appropriateness of generic preference-based measures should be examined in more conditions (and compared with CSPBMs). (2) Further quantitative and qualitative work is requested into the impact of, and reasons for labelling effects. (3) Use of add-ons for condition-specific measures (for side effects and comorbidities) and as a solution to the limitation of generic measures should be explored. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

An evaluation of patient-reported outcome measures in lower limb reconstruction surgery.

PURPOSE: To assess the measurement properties (acceptability, validity, reliability and responsiveness), of the MOS 36-Item Short-Form Health Survey (SF-36), the EQ-5D, the Short-Form McGill Pain Questionnaire (SF-MPQ) and the Musculoskeletal Functional Assessment Instrument (MFA), in patients who have undergone limb reconstruction surgery (LRS). METHODS: Four instruments measuring patient-reported outcome were completed at baseline and 12 months from surgery. RESULTS: 101 LRS patients were recruited with 95 responding at baseline and 71 at a 12-month follow-up. Response rates at baseline were over 94%. In three instruments, there was evidence of floor or ceiling effect, the exception being the EQ-5D. Cronbach's α statistics of internal consistency reliability were acceptable at ≥ 0.80 for all dimensions of the MFA, the SF-MPQ PRI(S) and seven of the SF-36 dimensions. When comparing mean changes in scores between baseline and 12 months, the most responsive measure was the SF-36 with an average Standardised Response Mean of 0.48 for those who reported their health as better. Statistically significant differences were observed between the health change groups ('worse', 'better' and 'same') for four dimensions of the SF-36, the two summary scores and the SF-6D. CONCLUSIONS: Variation and poor performance of some of the instruments resulted in a recommendation of using the SF-36 and the SF-6D for LRS patients.

An updated systematic review of Health State Utility Values for osteoporosis related conditions.

INTRODUCTION: An important component of cost effectiveness models in the field of osteoporosis is the set of Health State Utility Values (HSUVs) used for key fracture outcomes. This paper presents a review of HSUVs for key osteoporotic states (hip, wrist, shoulder, clinical, and morphometric vertebral fractures, established osteoporosis, and interaction of several fractures). It provides an update to the systematic review conducted by Brazier et al. (Osteoporos Int 13(10):768-776, 2002). MATERIALS AND METHODS: A systematic search was undertaken of the main literature databases for HSUVs for established osteoporosis, vertebral, hip, wrist, and shoulder fractures were identified. Studies meeting the inclusion criteria were reviewed in terms of the patient population, the method of describing health (if not obtained directly from patients), the method of valuing health states and the source of values. RESULTS: Estimates of Health State Utility Values were found across the osteoporosis conditions from 27 studies. A wide range of empirical estimates were found, partly due to differences in valuation technique (VAS, SG, TTO), descriptive system and differences in respondents (population or patient), the perspective of the task (own health or a scenario), sample size, and study quality. CONCLUSION: The paper provides a set of multipliers representing the loss in HSUVs for use as a "reference case" in cost-effectiveness models.

Randomised clinical trial, observational study and assessment of cost-effectiveness of the treatment of varicose veins (REACTIV trial).

OBJECTIVES: To establish the cost-effectiveness of surgery and sclerotherapy for the treatment of varicose veins. DESIGN: Randomised controlled trials (RCTs) were carried out for conservative treatment, sclerotherapy and surgery for varicose veins. An economic analysis was carried out alongside the randomised trial. Economic modelling was undertaken based on the primary data collection and a literature review (database searches undertaken in April 2000 and updated in March 2001). SETTING: Primary data collection was from a large district general hospital and a teaching hospital both in England over a 2-year period from January 1999. Cost-effectiveness analysis and economic modelling were carried out using an NHS perspective. PARTICIPANTS: A total of 1009 patients were recruited. INTERVENTIONS: Thirty-four patents were randomised in Group 1 (minor varicose veins with no reflux, randomised between conservative treatment and sclerotherapy), 77 in Group 2 (moderate varicose veins with reflux, randomised between surgery and sclerotherapy) and 246 in Group 3 (severe varicose veins with reflux, randomised between conservative treatment and surgery). The remaining 652 patients formed the observational part of the study. MAIN OUTCOME MEASURES: The cost-effectiveness analysis was based on NHS treatment costs for the 2002--3 financial year, and utilities based on the Short Form 6D (SF-6D) preference-based health measure. For the clinical trial, the outcome measures were health-related quality of life (HRQoL) [Short Form with 36 Items (SF-36), EuroQol quality of life questionnaire (EQ-5D), visual analogue scale (VAS) and standard gamble], symptomatic relief, anatomical extent (for which a new classification was developed and validated), patient satisfaction and the incidence of complications. RESULTS: Of the RCTs, only the Group 3 trial was large enough to provide clear results. This showed that surgical treatment produced better results than conservative treatment in terms of HRQoL, symptomatic relief, anatomical extent and patient satisfaction. Clinical outcomes of surgery and sclerotherapy showed significant improvement in the extent of varicose veins, symptomatic and HRQoL parameters. Cost-effectiveness analysis based on the Group 3 trial showed that the surgery produced an estimated discounted benefit of 0.054 quality-adjusted life-year (QALY) over a 2-year period, with an additional discounted cost of pound 387.45, giving an incremental cost-effectiveness ratio (ICER) of pound 7175 per QALY. Economic modelling suggested that surgery produced a still greater benefit when considered with a 10-year time horizon, with an ICER of pound 1936 per QALY. Injection sclerotherapy produced an incremental benefit of approximately 0.044 QALY at a cost of pound 155 when compared with conservative treatment, giving an ICER of pound 3500 per QALY. When surgery was compared with sclerotherapy, surgery produced greater benefit with a lower ICER (showing extended dominance). CONCLUSIONS: Standard surgical treatment of varicose veins by saphenofemoral ligation, stripping and multiple phlebectomies is a clinically effective and cost-effective treatment for varicose veins, with an ICER well below the threshold normally considered appropriate for the funding of treatments within the NHS. Injection sclerotherapy also appears to be cost-effective, but produces less overall benefit, with a higher ICER than surgery for patients with superficial venous reflux. In minor varicose veins without reflux, sclerotherapy is likely to provide a small average benefit with acceptable cost-effectiveness. Research is needed into methods for accurate and acceptable utility evaluations for conditions with relatively minor effect on HRQoL and also for a validated and standardised method of classification for varicose veins.

Cost-effectiveness analysis of surgery versus conservative treatment for uncomplicated varicose veins in a randomized clinical trial.

BACKGROUND: Despite being a common procedure, the cost effectiveness of surgery for varicose veins has not been established. METHODS: Cost-effectiveness analysis was carried out alongside a randomized clinical trial at two vascular units within National Health Service (NHS) hospitals. Some 246 patients with uncomplicated varicose veins and evidence of saphenofemoral or saphenopopliteal reflux were allocated randomly to receive either conservative management or surgical treatment. Incremental cost per quality-adjusted life year (QALY) gained at 24 months following randomization was calculated. RESULTS: Total NHS costs during the 2-year study period were higher for the surgically treated group (733 UK pounds) than for those who had conservative treatment (345 UK pounds). The difference in costs was statistically significant. The mean incremental health gain from surgical treatment at 24 months was 0.083 QALYs, leading to a base-case estimate of 4682 UK pounds per QALY gained. Assuming an implicit threshold maximum willingness-to-pay value of 20 000 UK pounds for a QALY, the probability of surgical treatment for varicose veins falling below this threshold value was 70 per cent. This result was found to be robust to sensitivity analysis. CONCLUSION: For patients with uncomplicated varicose veins and evidence of saphenofemoral or saphenopopliteal reflux, surgical treatment for varicose veins offers a modest health benefit for relatively little additional NHS cost relative to conservative treatment.

Randomized clinical trial comparing surgery with conservative treatment for uncomplicated varicose veins.

BACKGROUND: Surgical treatment of medically uncomplicated varicose veins is common, but its clinical effectiveness remains uncertain. METHODS: A randomized clinical trial was carried out at two large acute National Health Service hospitals in different parts of the UK (Sheffield and Exeter). Some 246 patients were recruited from 536 consecutive referrals to vascular outpatient clinics with uncomplicated varicose veins suitable for surgical treatment. Conservative management, consisting of lifestyle advice, was compared with surgical treatment (flush ligation of sites of reflux, stripping of the long saphenous vein and multiple phlebectomies, as appropriate). Changes in health status were measured using the Short Form (SF) 6D and EuroQol (EQ) 5D, quality of life instruments based on SF-36 and EuroQol, complications of treatment, symptomatic measures, anatomical extent of varicose veins and patient satisfaction. RESULTS: In the first 2 years after treatment there was a significant quality of life benefit for surgery of 0.083 (95 per cent confidence interval (c.i.) 0.005 to 0.16) quality-adjusted life years (QALYs) based on the SF-6D score and 0.13 (95 per cent c.i. 0.016 to 0.25) based on the EQ-5D score. Significant benefits were also seen in symptomatic and anatomical measures. CONCLUSION: Surgical treatment provides symptomatic relief and significant improvements in quality of life in patients referred to secondary care with uncomplicated varicose veins.

The development of a preference-based measure of health in children with atopic dermatitis.

BACKGROUND: Outcomes of health care interventions can be measured in many different ways, but there has been growing interest in the role that quality-adjusted life-years (QALYs) can play in informing priorities in health care. While existing generic preference-based measures can be used to obtain QALYs, these measures may often be inappropriate for some conditions such as atopic dermatitis (AD). These measures are also usually developed for adults and may not capture the domains pertinent to children. OBJECTIVES: To develop a preference-based quality-of-life measure for use in children with AD. METHODS: Items generated from interviews conducted with parents of children with AD were used to form a health state classification system that gives 16 unique health states. One hundred and fifty members of the general population were interviewed to derive preference weights for these states, following the methods used in the valuation of the Health Utilities Index 2 (HUI 2). Each person valued 10 health states using the standard gamble technique. The primary analysis was the estimation of mean health state values for each of the 16 states. RESULTS: Mean values across the 16 health states range from 0.36 (SD = 0.36) for the worst state to 0.84 (SD = 0.19) on a scale from zero to one, where zero is for health states thought to be as bad as being dead and one is for perfect health. There was some support for the validity of the values from the fact that the values were logically consistent with the ordering of the health state classification system. CONCLUSIONS: These results show the perceived importance of the defined health states of childhood AD to the general population. The resultant health state classification and values can be used to calculate QALYs for use in assessing the cost-effectiveness of interventions for children with AD.

Treating dyspepsia with acupuncture and homeopathy: reflections on a pilot study by researchers, practitioners and participants.

OBJECTIVES: For people with dyspepsia who are receiving orthodox general practice care, what is the effect on outcome and on NHS costs of adding treatment by a choice of acupuncture or homeopathy? This paper describes and reflects upon a pilot study with user involvement. DESIGN: A randomised pilot study. Patients chose between acupuncture and homeopathy and were then randomised to this preference or to the control group of normal GP care. SETTING AND PARTICIPANTS: Sixty people with dyspepsia (>/=2 weeks) presenting in one UK general practice were recruited in consultations and by letter to those on repeat prescriptions. There were few exclusion criteria. The homeopath and the acupuncturist treated the patient individually according to their normal practice for up to 6 months. After the trial there was a focus group for participants. OUTCOME MEASURES: SF-36 health survey, Measure Yourself Medical Outcome Profile (MYMOP), and General Well-being Index (GWBI). Counts of prescriptions, consultations and referrals from practice computer records. RESULTS: No trend or significant difference between the groups for clinical outcome or NHS costs. Major costs for the 6 months, mean (S.D.) cost per patient, were general practitioner consultations pound 8 (18), prescriptions pound 64 (73), acupuncture pound 175 (52), homeopathy pound 105 (33). Participants gave insights and suggestions which will inform the full trial design. CONCLUSIONS: Reflection on the pilot study data and experience by participants, treating practitioners and researchers led to modifications in the design and a sample size calculation. How to demonstrate individual responses to treatment remains a problem.

A systematic review of health state utility values for osteoporosis-related conditions.

An important weakness of economic models in the field of osteoporosis has been the dependence on assumptions or expert judgements rather than empirical estimates for the utility values of key health events associated with osteoporosis such as hip, vertebral, wrist fracture and established osteoporosis. This paper seeks to identify the best available utility estimates for health states associated with osteoporosis and make recommendations about their use. It is based on a systematic search of the main literature databases. Studies meeting inclusion criteria have been reviewed in terms of the appropriateness of the valuation technique, the validity of the descriptive system (if one was used), the number and type of respondents, and overall quality of the study. Twenty three estimates of health state values (HSVs) were found across the four conditions from five studies. These empirical estimates were found to differ significantly from the commonly used assumptions in economic evaluation, but with a wide variation between estimates for the same state (0.32 to 0.80 for vertebral fracture states). This variation can be partly explained by the valuation technique, health state description and the background and perspective of respondent, and leaves scope for considerable discretion that could be abused. There are also problems in using values obtained from the study populations to those in economic models and the difficulty of predicting health state values in those who avoid a fracture. The review recommends a set of health state values as part of a "reference case" for use in economic models. Due to the paucity of good quality of estimates in this area, further recommendations are made regarding the design of future studies to collect HSVs relevant to economic models.

Economics of surgery.

The time has come to subject surgery to the same rigours of economic assessment that other health-care sectors are already receiving--namely, the comparative assessment of costs and benefits. The surgical management of gallstones provides a good example of the role of economics in surgery. Gallstone disease is common and patients are usually referred to a surgeon, but the threshold for intervention is not agreed and varies widely, with considerable implications for resources. Gallstone removal has been subject to much innovation over the past 10 years, yet economic assessment of laparoscopic and "mini" cholecystectomy and of gallstone lithotripsy is rare, despite the fact that operation rates have increased by up to 50% in some countries. For surgery to compete with other interventions, economic assessment of new surgical techniques will be increasingly important. This assessment should be based on well-conducted clinical trials in which interventions are provided in a routine service setting, and in which benefits are assessed among other things on the basis of the patient's perceived quality of life. Economic assessment often needs data beyond those collected in a clinical trial, however pragmatic the trial design, so modelling will often be required, incorporating a range of sources of evidence. Finally, evidence alone will not be enough to promote cost-effective practices. The take-up of surgical techniques will always be affected by the way hospitals and surgeons are remunerated. Affecting practice requires a realistic system of reimbursement that reflects evidence on cost effectiveness.