Health technology assessment : HTA
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Health Technol Assess · Jan 2001
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialExtended scope of nursing practice: a multicentre randomised controlled trial of appropriately trained nurses and pre-registration house officers in pre-operative assessment in elective general surgery.
(1) To determine whether pre-operative assessment carried out by an appropriately trained nurse (ATN) is equivalent in quality to that carried out by a pre-registration house officer (PRHO). (2) To assess whether pre-assessments carried out by ATNs and PRHOs are equivalent in terms of cost. (3) To determine whether assessments carried out by ATNs are acceptable to patients. (4) To investigate the quality of communication between senior medical staff and ATNs. ⋯ This study demonstrated no reason to inhibit the development of fully nurse-led pre-operative assessment, provided that the nurses are appropriately trained and maintain sufficient workload to retain skills. CONCLUSIONS--IMPLICATIONS FOR THE HEALTH SERVICE: ATNs provide an acceptable and efficient alternative to PRHOs for the purposes of routine pre-operative assessment. Consideration will have to be given, however, to the positions of these nurses within the surgical team, and also to their career structure. CONCLUSIONS--RECOMMENDATIONS FOR FUTURE RESEARCH: Further research is needed in the following areas: (1) the extent and type of training needed for nurses undertaking the pre-operative assessment role; (2) the use, costs and benefits of routine pre-operative testing.
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Health Technol Assess · Jan 2001
Review Comparative StudyA rapid and systematic review of the clinical effectiveness and cost-effectiveness of topotecan for ovarian cancer.
Ovarian cancer is the most common gynaecological cancer with an annual incidence of 21.6 per 100,000 in England and Wales. Due to the often asymptomatic nature of the early stages of the disease, most cases are not detected until the advanced stages. Consequently, the prognosis after diagnosis is poor and the 5-year survival rate in the UK is only about 30%. Current recommendations suggest that first-line chemotherapy for ovarian cancer should involve paclitaxel and platinum (Pt)-based therapy (cisplatin/ carboplatin), however, most patients develop resistant or refractory disease and require second-line therapy. Patients may respond to re-challenge with Pt-agents if the treatment-free interval is > 6 months, but an alternative is often required. Topotecan is one of six drugs currently licensed in the UK for second-line therapy, and recent reviews suggest that it has modest efficacy in the treatment of advanced disease and performs favourably against paclitaxel. However, these reviews are based on a limited number of reports mainly consisting of non-randomised Phase I and II studies. ⋯ RECOMMENDATIONS FOR RESEARCH: Further good quality RCTs and CEAs are required comparing topotecan with other licensed and potentially useful (soon to be licensed) second-line treatments for ovarian cancer. At present, it is difficult to make any decisions about topotecan and other drugs for second-line therapy without good quality direct comparisons. In view of the ongoing studies identified, an update of the current review should be considered in approximately 18 months (Summer 2002) or possibly sooner if the recently commissioned National Institute for Clinical Excellence review of caelyx for ovarian cancer identifies additional data relevant to topotecan.
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Health Technol Assess · Jan 2001
ReviewStatistical assessment of the learning curves of health technologies.
(1) To describe systematically studies that directly assessed the learning curve effect of health technologies. (2) Systematically to identify 'novel' statistical techniques applied to learning curve data in other fields, such as psychology and manufacturing. (3) To test these statistical techniques in data sets from studies of varying designs to assess health technologies in which learning curve effects are known to exist. METHODS - STUDY SELECTION (HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW): For a study to be included, it had to include a formal analysis of the learning curve of a health technology using a graphical, tabular or statistical technique. METHODS - STUDY SELECTION (NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH): For a study to be included, it had to include a formal assessment of a learning curve using a statistical technique that had not been identified in the previous search. ⋯ There was a hierarchy of methods for the identification and measurement of learning, and the more sophisticated methods for both have had little if any use in health technology assessment. This demonstrated the value of considering fields outside clinical research when addressing methodological issues in health technology assessment. CONCLUSIONS - TESTING OF STATISTICAL METHODS: It has been demonstrated that the portfolio of techniques identified can enhance investigations of learning curve effects. (ABSTRACT TRUNCATED)
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Health Technol Assess · Jan 2001
ReviewSubgroup analyses in randomised controlled trials: quantifying the risks of false-positives and false-negatives.
Subgroup analyses are common in randomised controlled trials (RCTs). There are many easily accessible guidelines on the selection and analysis of subgroups but the key messages do not seem to be universally accepted and inappropriate analyses continue to appear in the literature. This has potentially serious implications because erroneous identification of differential subgroup effects may lead to inappropriate provision or withholding of treatment. ⋯ While it is generally recognised that subgroup analyses can produce spurious results, the extent of the problem is almost certainly under-estimated. This is particularly true when subgroup-specific analyses are used. In addition, the increase in sample size required to identify differential subgroup effects may be substantial and the commonly used 'rule of four' may not always be sufficient, especially when interactions are relatively subtle, as is often the case. CONCLUSIONS--RECOMMENDATIONS FOR SUBGROUP ANALYSES AND THEIR INTERPRETATION: (1) Subgroup analyses should, as far as possible, be restricted to those proposed before data collection. Any subgroups chosen after this time should be clearly identified. (2) Trials should ideally be powered with subgroup analyses in mind. However, for modest interactions, this may not be feasible. (3) Subgroup-specific analyses are particularly unreliable and are affected by many factors. Subgroup analyses should always be based on formal tests of interaction although even these should be interpreted with caution. (4) The results from any subgroup analyses should not be over-interpreted. Unless there is strong supporting evidence, they are best viewed as a hypothesis-generation exercise. In particular, one should be wary of evidence suggesting that treatment is effective in one subgroup only. (5) Any apparent lack of differential effect should be regarded with caution unless the study was specifically powered with interactions in mind. CONCLUSIONS--RECOMMENDATIONS FOR RESEARCH: (1) The implications of considering confidence intervals rather than p-values could be considered. (2) The same approach as in this study could be applied to contexts other than RCTs, such as observational studies and meta-analyses. (3) The scenarios used in this study could be examined more comprehensively using other statistical methods, incorporating clustering effects, considering other types of outcome variable and using other approaches, such as Bootstrapping or Bayesian methods.
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Clinical guidelines, defined as 'systematically developed statements to assist both practitioner and patient decisions in specific circumstances', have become an increasingly familiar part of clinical care. Guidelines are viewed as useful tools for making care more consistent and efficient and for closing the gap between what clinicians do and what scientific evidence supports. Interest in clinical guidelines is international and has its origin in issues faced by most healthcare systems: rising healthcare costs; variations in service delivery with the presumption that at least some of this variation stems from inappropriate care; the intrinsic desire of healthcare professionals to offer, and patients to receive, the best care possible. Within the UK, there is ongoing interest in the development of guidelines and a fast-developing clinical-effectiveness agenda within which guidelines figure prominently. Over the last decade, the methods of developing guidelines have steadily improved, moving from solely consensus methods to methods that take explicit account of relevant evidence. However, UK guidelines have tended to focus on issues of effectiveness and have not explicitly considered broader issues, particularly cost. This report describes the methods developed to handle benefit, harm and cost concepts in clinical guidelines. It reports a series of case studies, each describing the development of a clinical guideline; each case study illustrates different issues in incorporating these different types of evidence. ⋯ The focus of this project was to explore the methods of incorporating cost issues within clinical guidelines. However, the process of reviewing evidence in guideline development groups is becoming increasingly sophisticated, not only in considerations of cost but also in review techniques and group process. At the outset of the project it was unclear how narrowly or broadly the concept of 'cost' could be considered. (ABSTRACT TRUNCATED)