Clinical trials : journal of the Society for Clinical Trials
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Missing data are a potential source of bias, and their handling in the statistical analysis can have an important impact on both the likelihood and degree of such bias. Inadequate handling of the missing data may also result in invalid variance estimation. The handling of missing values is more complex in cluster randomised trials, but there are no reviews of practice in this field. ⋯ Missing data are present in the majority of cluster randomised trials. However, they are poorly reported, and most authors give little consideration to the assumptions under which their analysis will be valid. The majority of the methods currently used are valid under very strong assumptions about the missing data, whose plausibility is rarely discussed in the corresponding reports. This may have important consequences for the validity of inferences in some trials. Methods which result in valid inferences under general Missing-at-Random assumptions are available and should be made more accessible.
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Randomized Controlled Trial Multicenter Study Comparative Study
The design and rationale of a multicenter clinical trial comparing two strategies for control of systolic blood pressure: the Systolic Blood Pressure Intervention Trial (SPRINT).
High blood pressure is an important public health concern because it is highly prevalent and a risk factor for adverse health outcomes, including coronary heart disease, stroke, decompensated heart failure, chronic kidney disease, and decline in cognitive function. Observational studies show a progressive increase in risk associated with blood pressure above 115/75 mm Hg. Prior research has shown that reducing elevated systolic blood pressure lowers the risk of subsequent clinical complications from cardiovascular disease. However, the optimal systolic blood pressure to reduce blood pressure-related adverse outcomes is unclear, and the benefit of treating to a level of systolic blood pressure well below 140 mm Hg has not been proven in a large, definitive clinical trial. ⋯ The Systolic Blood Pressure Intervention Trial will provide important information on the risks and benefits of intensive blood pressure treatment targets in a diverse sample of high-risk participants, including those with prior cardiovascular disease, chronic kidney disease, and those aged ≥75 years.
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Randomized Controlled Trial
A trial of in-hospital, electronic alerts for acute kidney injury: design and rationale.
Acute kidney injury is common in hospitalized patients, increases morbidity and mortality, and is under-recognized. To improve provider recognition, we previously developed an electronic alert system for acute kidney injury. To test the hypothesis that this electronic acute kidney injury alert could improve patient outcome, we designed a randomized controlled trial to test the effectiveness of this alert in hospitalized patients. The study design presented several methodologic, ethical, and statistical challenges. ⋯ Our study demonstrates the feasibility of designing an ethical randomized controlled trial of an early electronic alert for acute kidney injury without obtaining informed consent from individual participants. Our study outcome may serve as a model for other studies of acute kidney injury, insofar as our paradigm accounts for the effect that early death and dialysis have on assessment of acute kidney injury severity as defined by maximum achieved serum creatinine.