Health technology assessment : HTA
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Health Technol Assess · Jan 2001
Issues in methodological research: perspectives from researchers and commissioners.
(1) Methodological research has few well-defined tools and processes analogous to those available for reviews and data collection in substantive health technology assessment. (2) This project was set up to obtain researchers' and others' views on the innovative projects on research methodology under the NHS Health Technology Assessment Programme and the usefulness of the research. (3) The study was intended to span both epistemological and management issues. (4) The following issues were explored: (a) the degree to which researchers would feel constrained by the "Cochrane" approach to systematic reviews when undertaking reviews of a methodological nature; (b) whether methodological projects may require exceptional design and management arrangements, in view of their novelty, subjectivity and complexity; (c) whether researchers would seek out other methods, in addition to undertaking reviews of argument, as a means of extending their understanding of methodological issues (there may be three categories of research methods in methodology: reviews of methodological argument, studies that use the literature as a source of data, and research that collects new primary data); (d) whether the Methodology Programme overall can be considered a "success". ⋯ UNDERTAKING METHODOLOGICAL RESEARCH: VIEWS OF RESEARCHERS (PROJECT MANAGEMENT--TIMING AND TIME MANAGEMENT): (1) A majority of projects were completed within 3 months of their due date. Those studies completed roughly on time were considered to have efficient junior researchers and good project management, including clear deadlines for different stages of the research. (2) Some studies had severe problems of time management. Too much time tended to be spent on collecting and reading the literature and the writing stage was not always well planned. Referees' comments were also slow in coming. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2000
Review Comparative StudyA systematic review of comparisons of effect sizes derived from randomised and non-randomised studies.
There is controversy about the value of evidence about the effectiveness of healthcare interventions from non-randomised study designs. Advocates for quasi-experimental and observational (QEO) studies argue that evidence from randomised controlled trials (RCTs) is often difficult or impossible to obtain, or is inadequate to answer the question of interest. Advocates for RCTs point out that QEO studies are more susceptible to bias and refer to published comparisons that suggest QEO estimates tend to find a greater benefit than RCT estimates. However, comparisons from the literature are often cited selectively, may be unsystematic and may have failed to distinguish between different explanations for any discrepancies observed. ⋯ Relevant literature was identified from: The Cochrane Library, MEDLINE, EMBASE, DARE, and the Science Citation Index. References of relevant papers already identified experts. Electronic searches were very difficult to design and yielded few papers for the first strategy and when identifying study designs. CHOICE OF INTERVENTIONS TO REVIEW FOR STRATEGIES 1 AND 2: For strategy 1, any intervention was eligible. For strategy 2, interventions for which the population, intervention and outcome investigated were anticipated to be homogeneous across studies were selected for review: Mammographic screening (MSBC) of women to reduce mortality from breast cancer. Folic acid supplementation (FAS) to prevent neural tube defects in women trying to conceive. DATA EXTRACTION AND QUALITY ASSESSMENT: Data were extracted by the first author and checked by the second author. Disagreements were negotiated with reference to the paper concerned. For strategy 1, study quality was scored using a checklist to assess whether the RCT and QEO study estimates were derived from the same populations, whether the assessment of outcomes was 'blinded', and the extent to which the QEO study estimate took account of possible confounding. For strategy 2, a more detailed instrument was used to assess study quality on four dimensions: the quality of reporting, the generalisability of the results, and the extent to which estimates of effectiveness may have been subject to bias or confounding. All quality assessments were carried out by three people. DATA SYNTHESIS AND ANALYSIS: For strategy 1, pairs of comparisons between RCT and QEO study estimates were classified as high or low quality. Seven indices of the size of discrepancies between estimates of effect size and outcome frequency were calculated, where possible, for each comparison. Distributions of the size and direction of discrepancies were compared for high- and low-quality comparisons. FOR STRATEGY 2, THREE ANALYSES WERE CARRIED OUT: Attributes of the instrument were described by k statistics, percentage agreement, and Cronbach's a values. Regression analyses were used to investigate -variations in study quality. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2000
ReviewOutcome measures for adult critical care: a systematic review.
1. To identify generic and disease specific measures of impairment, functional status and health-related quality of life that have been used in adult critical care (intensive and high-dependency care) survivors. 2. To review the validity, reliability and responsiveness of the measures in adult critical care survivors. 3. To consider the implications for future policy and to make recommendations for further methodological research. 4. To review what is currently known of the outcome of adult critical care. ⋯ MEASURES USED IN CRITICAL CARE: Measures of impairment were largely confined to the respiratory system so are almost certainly not appropriate for many critical care survivors. They can be categorised as respiratory volumes (e.g. vital capacity), gas flow within the respiratory system (e.g. forced expiratory volume in 1 second (FEV1)), pulmonary diffusing capacity (e.g. carbon monoxide diffusing capacity) and visualisation of the upper airway (e.g. bronchoscopy). Multiple tests are often performed. Eight measures of physical functional status were used, five generic and three disease-specific. The most frequently used generic measures were multi-item scales. Two single-item global measures attempted to capture a person's overall activity level or functional status. Five multi-item measures of mental functional status were used, four generic and one specific to trauma patients. The generic measures were either confined to assessing depressive symptoms or also encompassed a measure of anxiety. Measures of neuropsychological functioning relate to a person's cognition, attention, ability to process information and memory. Apart from one single-item measure, which focused on communication level, six multi-item measures were used with critical care survivors. Such measures are particularly appropriate for use with survivors of head injury or other neurological insult and, in that sense, they are disease-specific rather than generic measures. Single item measures of recovery were frequently used but researchers often invented their own, so there was little consistency in the wording. These measures had five principal foci - return to work, return to own home, degree of recovery, productivity and chronic health status. One multi-item scale was also used. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2000
ReviewTreatments for fatigue in multiple sclerosis: a rapid and systematic review.
Multiple sclerosis (MS) is an important problem both for people with the disease and for society. There is no cure, and alleviation of symptoms forms the cornerstone of care. Excessive fatigue that severely limits activity is experienced by at least two-thirds of the estimated 60,000 people with MS in the UK. ⋯ There is insufficient evidence to allow people with MS, clinicians or policy makers to make informed decisions on the appropriate use of the many treatments on offer. Only amantadine appears to have some proven ability to alleviate the fatigue in MS, though only a proportion of users will obtain benefit and then only some of these patients will benefit sufficiently to take the drug in the long term. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: The frequency, severity and impact of fatigue, the poverty of available research, and the absence of any ongoing research, suggest that new research is an urgent priority. People with MS, clinicians and policy makers should work together to ensure that the evidence required is collected as quickly as possible by encouraging involvement in rigorous research. Research should not be restricted to the two drugs reviewed in depth in this report. All interventions identified in the scoping review (see above) should be considered, as should basic scientific research into the underlying mechanism of fatigue in MS.