Health technology assessment : HTA
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Health Technol Assess · Jan 2001
Review Comparative StudyComparison of the effectiveness of inhaler devices in asthma and chronic obstructive airways disease: a systematic review of the literature.
Asthma and chronic obstructive pulmonary disease (COPD) are common diseases of the airways and lungs that have a major impact on the health of the population. The mainstay of treatment is by inhalation of medication to the site of the disease process. This can be achieved by a number of different device types, which have wide variations in costs to the health service. A number of different inhalation devices are available. The pressurised metered-dose inhaler (pMDI) is the most commonly used and cheapest device, which may also be used in conjunction with a spacer device. Newer chlorofluorocarbons (CFC)-free inhaler devices using hydrofluoroalkanes (HFAs) have also been developed. The drug is dissolved or suspended in the propellant under pressure. When activated, a valve system releases a metered volume of drug and propellant. Other devices include breath-actuated pMDIs (BA-pMDI), such as Autohaler and Easi-Breathe. They incorporate a mechanism activated during inhalation that triggers the metered-dose inhaler. Dry powder inhalers (DPI), such as Turbohaler, Diskhaler, Accuhaler and Rotahaler, are activated by inspiration by the patient. The powdered drug is dispersed into particles by the inspiration. With nebulisers oxygen, compressed air, or ultrasonic power is used to break up solutions or suspensions of medication into droplets for inhalation. The aerosol is administered by mask or by a mouthpiece. There has been no previous systematic review of the evidence of clinical effectiveness and cost-effectiveness of these different inhaler devices. ⋯ This systematic review examined the evidence from clinical trials evaluating the clinical effectiveness of different inhaler devices in the delivery of inhaled corticosteroids and beta2-bronchodilators for patients with asthma and COPD. The evidence from the published clinical literature demonstrates no difference in clinical effectiveness between nebulisers and alternative inhaler devices compared to standard pMDI with or without a spacer device. The cost-effectiveness evidence therefore favours pMDIs (or the cheapest inhaler device) as first-line treatment in all patients with stable asthma unless other specific reasons are identified. Patients can use pMDIs as effectively as other inhaler devices as long as the correct inhalation technique is taught. CONCLUSIONS--RECOMMENDATIONS FOR RESEARCH: Further clinical trials are required to demonstrate any differences in the clinical effectiveness and cost-effectiveness of inhaler devices and nebulisers compared with pMDIs. These should be of sufficient statistical power and methodological rigour to demonstrate any clinical benefit. Trials should be undertaken in community settings to ensure the generalisability of results. Outcome measures should be more patient-centred and report adverse effects more completely. Reporting of data from trials should be improved.
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Health Technol Assess · Jan 2001
ReviewGeneral health status measures for people with cognitive impairment: learning disability and acquired brain injury.
Currently there is a wide range of health status measures that aim to assess general health status in people with cognitive impairment. However, the validity and/or applicability to this patient group are largely unknown. This has implications for the assessment of treatment outcomes and rehabilitation, for prognostic purposes, for planning services, and for determining the benefits and adverse effects of health technologies targeted at these patient groups. ⋯ (1) Existing general health status measures should be used with caution in individuals with cognitive impairments. (2) There is no evidence to indicate the most suitable general health status measure for use in economic evaluations of cognitive impairment. (3) There is little evidence to support the validity of proxy assessments in cognitively impaired populations. (ABSTRACT TRUNCATED)
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This report is concerned with the evaluation of measures broadly designed to measure quality of life (QoL) in children and adolescents, either by self-report or proxy raters. Four research questions were identified: (1) To what extent are adult measures used in the evaluation of healthcare interventions in children? (2) How appropriate are adult measures for use with children? (3) To what extent do child self-reports correspond with assessments made by parents and carers? (4) How feasible and reliable are proxy measures of QoL in different disease contexts? ⋯ Forty-three measures were identified (19 generic and 24 disease-specific). Sixteen measures allowed for completion by children and parent/caregiver; seven only allowed for completion by a proxy, and the remainder (n = 17) allowed only for child completion. The measures were described as QoL (n = 30), health status, (n = 2), perception of illness (n = 1), life satisfaction (n = 1) and quality of well-being (n = 1). RESULTS - TO WHAT EXTENT ARE ADULT MEASURES USED IN THE EVALUATION OF HEALTHCARE INTERVENTIONS IN CHILDREN?: Three studies were identified where adult measures were used with very few changes made for children. In 11 studies involving nine separate measures of QoL, adult measures were used as a model for work with children. RESULTS - HOW APPROPRIATE ARE ADULT MEASURES FOR USE WITH CHILDREN?: Adult measures may fail to tap the specific aspects of QoL that are important to the child. Measures based on adult work impose considerable response burden for children, in terms of length, reading skills and response scale. Wording and format of adult measures may need to be modified to account for children's cognitive and language skills. More basic research is needed to determine the level of response burden that children of different ages can manage. Assessments of difficulty (e.g. reading age) need to be routinely included with information about new measures. RESULTS - TO WHAT EXTENT DO CHILD SELF-REPORTS CORRESPOND WITH ASSESSMENTS MADE BY PARENTS AND CARERS?: Fourteen studies were identified in which concor-dance between child and parent was investigated, often as part of the development of a new measure. There was some evidence for greater concordance between child and parent for physical functioning compared with social and emotional domains, but greater heterogeneity in the latter measures may contribute to inconsistent results. There was no simple relationship between concordance and moderating variables such as age, gender and illness, but this conclusion was addressed only very rarely. RESULTS - HOW FEASIBLE AND RELIABLE ARE PROXY MEASURES OF QOL IN DIFFERENT DISEASE CONTEXTS?: Only five papers fulfilled the review criteria. Evaluation is difficult because authors fail to justify their choice of measures, and do not report critical information such as completion rates or missing data. Use of existing measures can potentially eliminate the time and expense required to develop a comprehensive measure of QoL, but a full battery of standardised tests may be expensive in terms of time for administration and scoring. In addition, battery measures tend to be lengthy and therefore demanding for sick patients. They are not recommended for work with children. RECOMMENDATIONS FOR RESEARCH - MINIMUM CRITERIA FOR NEW MEASURES: A set of procedures needs to be established for the development of new measures. These need to draw on the experience gained in development of child and adult measures to date. Basic research to enhance understanding of how children interpret questions in QoL measures is recommended. We need to understand the differences in meaning of items between children and adults, and between children of different ages. Some attempt to develop measures for children of 6 years or more have been reported, and these should be further developed. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2001
ReviewA rapid and systematic review of the clinical effectiveness and cost-effectiveness of orlistat in the management of obesity.
The prevalence of obesity in developed societies is increasing. Obesity is associated with an increased risk of co-morbidity, including cardiovascular disease and diabetes. Following the withdrawal of fenfluramine and dexfenfluramine, interest has focused on a novel anti-obesity drug orlistat. ⋯ To systematically assess the clinical effectiveness and cost-effectiveness of orlistat in the management of obesity. METHODS - SEARCH STRATEGY: Nineteen electronic databases were searched from inception to June 2000. Additionally, Internet searches were carried out, bibliographies of retrieved articles were examined and submissions were received from the manufacturer of orlistat. METHODS - INCLUSION AND EXCLUSION CRITERIA: Randomised controlled trials (RCTs) evaluating the effectiveness of orlistat used for weight loss or maintenance of weight loss in overweight or obese patients were eligible for inclusion. Primary outcome measures were changes in body weight, fat content or fat distribution. Secondary outcomes were changes in obesity-related risk-factor profiles, such as lipid levels, indicators of glycaemic control and blood pressure. Studies recruiting people with eating disorders such as anorexia nervosa and bulimia nervosa were excluded. METHODS - PROCESS OF STUDY SELECTION: Assessment of titles and abstracts was performed independently by two reviewers. If either reviewer considered a reference to be relevant, the full paper was retrieved. Full papers were assessed against the review selection criteria by two independent reviewers, and disagreements were resolved through discussion. METHODS - DATA EXTRACTION: Data were extracted by one reviewer into structured summary tables and checked by a second reviewer. Any disagreements about data were resolved by discussion. METHODS - QUALITY ASSESSMENT: Each included trial was assessed against a comprehensive checklist for methodological quality. Quality assessment was performed independently by two reviewers with disagreements resolved by discussion. METHODS - METHODS OF ANALYSIS/SYNTHESIS: This report is a narrative summary, with results grouped according to study endpoint. Statistical pooling was undertaken in groups of trials that were considered to be sufficiently similar. METHODS - ESTIMATION OF QUALITY OF LIFE, COSTS AND COST-EFFECTIVENESS AND/OR COST PER QUALITY-ADJUSTED LIFE-YEAR: Relevant economic evaluations were identified from the search strategy described above. Assessment of methodological quality was undertaken using principles outlined in published guidelines. METHODS - COMPANY SUBMISSIONS: Data from company submissions were subject to the same selection and appraisal processes as other studies considered for inclusion in the review, except that only RCTs with a duration of at least 1 year were selected. RESULTS - RESULTS OF THE SEARCH STRATEGY: Fourteen RCTs (including three company submissions) and two economic evaluations (including one company submission) were included in the review. RESULTS - RESULTS OF THE QUALITY ASSESSMENT: Methodological quality of trials was moderate to good. The main problems were lack of detail on methods used to produce true randomisation, small sample sizes in some cases and failure to use intention-to-treat analysis. It is likely that maintenance of blinding was difficult due to adverse effects associated with the study medication. RESULTS - EVIDENCE OF CLINICAL EFFECTIVENESS AND COST-EFFECTIVENESS: Most of the trials showed greater weight loss and better weight maintenance with orlistat compared to placebo at all endpoints (statistically significant differences for both outcomes). Orlistat 120 mg three times daily was the optimum regimen in terms of weight loss. Most trials showed significant improvement in at least some lipid concentration parameters, and, in three RCTs, orlistat produced statistically significant reductions in blood pressure relative to placebo. In obese patients with type 2 diabetes, orlistat resulted in a significantly greater weight loss at 1 year compared with placebo, and some parameters of glycaemic control and lipid concentration also showed significantly greater improvements compared with placebo. The incidence of gastrointestinal adverse events was consistently higher in orlistat groups compared with placebo, and orlistat use was associated with lower serum levels of fat-soluble vitamins. The cost per quality-adjusted life-year for orlistat was 45,881 UK pounds. CONCLUSIONS - IMPLICATIONS FOR CLINICAL PRACTICE: Although many trials have demonstrated statistically significant differences between groups in terms of weight loss in favour of orlistat versus placebo, the differences may not always be of clinical significance. The clinical significance of between-group differences for secondary outcomes may also be debatable. Possible adverse effects should be taken into account when prescribing orlistat, particularly gastrointestinal effects. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2001
ReviewEffects of educational and psychosocial interventions for adolescents with diabetes mellitus: a systematic review.
Insulin-dependent diabetes mellitus, also known as type 1 diabetes, is a life-threatening condition and is the third most common chronic illness among young people. As a result of minimal or non-existent insulin production, people with diabetes must take over the normally automatic task of regulation of blood glucose levels. This is achieved by a complex regimen involving multiple, daily administrations of insulin coordinated with dietary intake and energy expenditure and monitored by blood glucose testing. ⋯ The following conclusions were drawn from this review: (1) Educational and psychosocial interventions have small to medium beneficial effects on various diabetes management outcomes. (2) Well-designed trials of such interventions are needed in the UK (no completed RCTs of educational or psychosocial interventions for adolescents with type 1 diabetes conducted in the UK were found). (3) The evidence, arising primarily from studies in the USA, provides a starting point for the design of interventions in the UK. (4) Quantitative and narrative analysis of the evidence suggested that interventions are more likely to be effective if they demonstrate the inter-relatedness of the various aspects of diabetes management. (ABSTRACT TRUNCATED)