Health technology assessment : HTA
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Health Technol Assess · Sep 2005
ReviewConceptual framework and systematic review of the effects of participants' and professionals' preferences in randomised controlled trials.
To develop a conceptual framework of preferences for interventions in the context of randomised controlled trials (RCTs), as well as to examine the extent to which preferences affect recruitment to RCTs and modify the measured outcome in RCTs through a systematic review of RCTs that incorporated participants' and professionals' preferences. Also to make recommendations on the role of participants' and professionals' preferences in the evaluation of health technologies. ⋯ Although patients and physicians often have intervention preferences, our review gives less support to the hypothesis that preferences significantly compromise the internal and external validity of trials. This review adds to the growing evidence that when preferences based on informed expectations or strong ethical objections to an RCT exist, observational methods are a valuable alternative. All RCTs in which participants and/or professionals cannot be masked to treatment arms should attempt to estimate participants' preferences. In this way, the amount of evidence available to answer questions about the effect of treatment preferences within and outwith RCTs could be increased. Furthermore, RCTs should routinely attempt to report the proportion of eligible patients who refused to take part because of their preferences for treatment. The findings also indicate a number of approaches to the design, conduct and analysis of RCTs that take account of participants' and/or professionals' preferences. This is referred to as a methodological tool kit for undertaking RCTs that incorporate some consideration of patients' or professionals' preferences. Future research into the amount and source of information available to patients about interventions in RCTs could be considered, with special emphasis on the relationship between sources inside and outside the RCT context. Qualitative research undertaken as part of ongoing RCTs might be especially useful. The processes by which this information leads to preferences in order to develop or extend the proposed expectancy--value framework could also be examined. Other areas for consideration include: how information about interventions changes participants' preferences; a comparison of the feasibility and effectiveness of different informed consent procedures; how strength of preference varies for different interventions within the same RCT and how these differences can be taken account of in the analysis; the differential effects of patients' and professionals' preferences on evidence arising from RCTs; and whether the standardised measurement of preferences within all RCTs (and analysis of the effect on outcome) would allow the rapid development of a significant evidence base concerning patient preferences, albeit in relation to a single preference design.
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Health Technol Assess · Sep 2005
ReviewThe clinical and cost-effectiveness of implantable cardioverter defibrillators: a systematic review.
To consider the clinical effectiveness and cost-effectiveness of implantable cardioverter defibrillators (ICDs) for arrhythmias. ⋯ The use of ICDs in the UK is increasing, but the technology is still under-utilised compared with other developed countries. Extending the current indications to patients with prior myocardial infarction and depressed heart function would impact on costs and service provision. Further research is needed on the risk stratification of patients in whom ICDs are most likely to be clinically and cost-effective. An evaluation of shock frequency on QoL is also required.