A prospective, randomized, pragmatic, health outcomes trial evaluating the incorporation of hylan G-F 20 into the treatment paradigm for patients with knee osteoarthritis (Part 2 of 2): economic results

AbstractObjective Viscosupplementation with hylan G-F 20 has recently become registered for treatment of patients with osteoarthritis (OA) of the knee in most parts of the world. The cost effectiveness and cost utility of this new therapeutic modality were determined as part of a Canadian prospective, randomized, 1-year, open-label, multicentered trial.Design A total of 255 patients were randomized to ‘Appropriate care with hylan G-F 20’ (AC+H) or ‘Appropriate care without hylan G-F 20’ (AC). Costs (1999 Canadian dollars) were collected from the societal viewpoint and included all costs related to OA of the knee and OA in all joints. Patients completed a number of outcomes questionnaires including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Health Utilities Index Mark 3 (HUI3). Data were collected at clinic visits (baseline, 12 months) and by telephone (1, 2, 4, 6, 8, 10, and 12 months).Results The AC+H group over the year had higher costs ($2125–$1415=$710, P< 0.05), more patients improved (69$2505/patient improved. The incremental cost–utility ratio was $10000/QALY gained. Sensitivity analyses and a second cost perspective gave similar results.Conclusion The cost–utility ratio is below the suggested Canadian adoption threshold. The results provide strong evidence for adoption of treatment with hylan G-F 20 in the patients and settings studied in the trial. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved

A quantum Monte Carlo study of the one-dimensional ionic Hubbard model

Quantum Monte Carlo methods are used to study a quantum phase transition in a 1D Hubbard model with a staggered ionic potential (D). Using recently formulated methods, the electronic polarization and localization are determined directly from the correlated ground state wavefunction and compared to results of previous work using exact diagonalization and Hartree-Fock. We find that the model undergoes a thermodynamic transition from a band insulator (BI) to a broken-symmetry bond ordered (BO) phase as the ratio of U/D is increased. Since it is known that at D = 0 the usual Hubbard model is a Mott insulator (MI) with no long-range order, we have searched for a second transition to this state by (i) increasing U at fixed ionic potential (D) and (ii) decreasing D at fixed U. We find no transition from the BO to MI state, and we propose that the MI state in 1D is unstable to bond ordering under the addition of any finite ionic potential. In real 1D systems the symmetric MI phase is never stable and the transition is from a symmetric BI phase to a dimerized BO phase, with a metallic point at the transition

Preferences and utilities for the symptoms of moderate to severe allergic asthma

Asthma, Valuation, Willingness to pay (WTP), Utility, Preference,

What should be reported in a methods section on utility assessment?

The measurement of utilities, or preferences, for health states, may be affected by the technique used. Unfortunately, in papers reporting utilities, it is often difficult to infer how the utility measurement was carried out. Purpose: To present a list of components that, when described, provide sufficient detail of the utility assessment. Methods: An initial list was prepared by one of the authors. A panel of eight experts was formed to add additional components. The components are drawn from six clusters that focus on the design of the study, the administration procedure, the health state descriptions, the description of the utility assessment method, the description of the indifference procedure, and the use of visual aids or software programs. The list was updated and redistributed. The components were judged by 14 experts for their importance of being mentioned in a Methods section. Results: Over 40 components were generated. Ten components were judged to be critical for inclusion in a paper not focussing on utility measurement: how were utilities collected, health state description, which utility assessment method, response and completion rates, use and specification of fixed duration, which software program, description of worst health state, matching or choice indifference search procedure, when was the assessment done, what visual aids were used. The interjudge reliability was satisfactory (Cronbach's alpha = 0.85). Discussion: The list of components important for utility papers may be used in various ways, for instance as a checklist while writing, reviewing or reading a Methods section, or while designing experiments. Guidelines are provided for a few components

Does greater exposure to own-health data make a difference on the visual analog scale?

Visual Analog Scale, Reproducibility, Stability, Reliability, ICC,

A cardiovascular extension of the Health Measurement Questionnaire

OBJECTIVE: To investigate the psychometric properties of a cardiovascular extension of an existing utility-based quality of life questionnaire (Health Measurement Questionnaire). The new instrument has been named the Utility Based Quality of life--Heart questionnaire, or UBQ-H. DESIGN: Explored the test-retest reliability, construct validity, and responsiveness of the UBQ-H. PATIENTS: A sample of 322 patients attending cardiac outpatient clinics were recruited from two large metropolitan teaching hospitals. A second sample of 1112 patients taking part in the LIPID trial was also used to investigate the validity and responsiveness of the UBQ-H. RESULTS: Ninety per cent of all UBQ-H questionnaires were returned, and item completion rates were high (median of less than 1% missing or N/A answers). Cronbach's alpha measure of internal consistency for the scales ranged between 0.79- 0.91, and each item was also most strongly correlated with its hypothesised domain than alternative domains. The intra-class test- retest reliability of the UBQ-H scales ranged from 0.65 to 0.81 for patients with stable health. Results supported the construct validity of the UBQ-H. The UBQ-H was significantly correlated with other information on quality of life (for example, General Health Questionnaire) as anticipated. The instrument was able to distinguish between contrasted groups of patients (for example, with versus without symptoms of dyspnoea, prior myocardial infarction versus none, etc), and was responsive to changes in health associated with adverse events requiring hospitalisation. CONCLUSIONS: The modifications made to the Health Measurement Questionnaire has resulted in an assessment designed for cardiovascular patients that has proved to be both reliable and valid.