Journal of clinical epidemiology
-
Direct evidence comes from research that directly compares the interventions in which we are interested when applied to the populations in which we are interested and measures outcomes important to patients. Evidence can be indirect in one of four ways. First, patients may differ from those of interest (the term applicability is often used for this form of indirectness). ⋯ Thirdly, outcomes may differ from those of primary interest-for instance, surrogate outcomes that are not themselves important, but measured in the presumption that changes in the surrogate reflect changes in an outcome important to patients. A fourth type of indirectness, conceptually different from the first three, occurs when clinicians must choose between interventions that have not been tested in head-to-head comparisons. Making comparisons between treatments under these circumstances requires specific statistical methods and will be rated down in quality one or two levels depending on the extent of differences between the patient populations, co-interventions, measurements of the outcome, and the methods of the trials of the candidate interventions.
-
To describe the characteristics and quality of reporting of cluster randomized trials (CRTs) in children published from 2004 to 2010. ⋯ Children-specific elements of reporting are needed to improve the quality of reporting of CRTs and consequently their planning and implementation.
-
In the GRADE approach, randomized trials start as high-quality evidence and observational studies as low-quality evidence, but both can be rated down if a body of evidence is associated with a high risk of publication bias. Even when individual studies included in best-evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. ⋯ The most popular of these is the funnel plot; all, however, have substantial limitations. Publication bias is likely frequent, and caution in the face of early results, particularly with small sample size and number of events, is warranted.
-
Comparative Study
Long-term projections of the harm-benefit trade-off in prostate cancer screening are more favorable than previous short-term estimates.
To project long-term estimates of the number needed to screen (NNS) and the additional number needed to treat (NNT) to prevent one prostate cancer death with prostate-specific antigen (PSA) screening in Europe and in the United States. ⋯ Long-term estimates of the NNS and the additional NNT are an order of magnitude lower than the short-term estimates published with the results of the ERSPC trial and may be consistent with cost-effective PSA screening in the general U.S. population.