Compared with previous meta-epidemiological studies, 1 6 8 9 10 misclassification of trials due to inadequate reporting 11 is therefore less likely to have introduced bias in our study.
All included criteria have empirical evidence that not using them in RCTs or not assessing them in systematic reviews results in bias in the estimates of treatment effect or in misclassification of trials as high or low quality.
Owing to potential selection bias and misclassification of exposure and outcome variables, trial-based estimates of MI incidence after breast cancer treatment are likely inaccurate.
However, this analysis did not adjust for confounding within the individual trials, and misclassification of hyperglycemic patients may have biased the results.
To reduce the risk of misclassification of ethics reporting practices and trials' characteristics, we used a consensus between two reviewers who independently extracted information about ethical and methodological factors from the published reports.
Misclassification of study endpoints in randomized clinical trials of screening tests has been well documented, yet its effect on study power, type I error rate, and risk ratio estimate have not been studied in depth.
3 25262727 Several trials lacked independent adjudication of events, therefore bias in either direction cannot be excluded, including bias towards the null owing to non-differential misclassification of events or assessor bias in trials without independent adjudication.
Because of randomization, most misclassification in the trial was likely to be nondifferential; that is, if subjects are underreporting disease, they are likely to be doing so equally while in the both the active treatment and the sham group.
In these circumstances a degree of misclassification of cause of death is inevitable, but if this is unrelated to trial arm (non-differential misclassification) then the effect of screening will be modestly underestimated at worst [ 11].
In addition, men in the intervention arm of the trial were uniformly screened for prostate cancer, therefore minimising misclassification of the outcome.
