Statistical heterogeneity among studies was assessed by the χ test (p < 0.10 was defined as indicating significant heterogeneity) and calculation of I. Publication bias was assessed by use of a funnel plot and the Egger test.
Investigators should provide detailed accounts of sample size calculations in publications of clinical trials of pain treatments, which is necessary for reporting transparency and communication of pre-trial design decisions.
For each component trial, we extracted the following data: sequence generating, allocation concealment, blinding, incomplete follow-up data, intention-to-treat analysis, sample size calculation, and year of publication.
8 Although good reasons exist for reporting sample size calculations in publications, 20 31 previous reviews of publications have found poor reporting of sample size calculations and their underlying assumptions.
The smaller the amount of publications used for the calculation, the larger is the impact of a few articles that have been cited often.
Sixty-five percent of publications reported a sample size calculation but only 38% provided all elements required to replicate the calculated sample size.
Heterogeneity was evaluated by Cochran Q test and calculation of the I2 statistic and publication bias by linear regression of standardized effect in relation to precision.
This process, though not perfect, ensures that the methods employed and the findings of the research receive a high level of scrutiny, such that an independent researcher could repeat the experiment or calculation of results, prior to their publication.
In this review, we examined the reporting quality of sample size calculations in 172 publications of double-blind randomized controlled trials of noninvasive pharmacologic or interventional (ie, invasive) pain treatments published in European Journal of Pain, Journal of Pain, and Pain from January 2006 through June 2013.
His many publications include the calculation of the velocity necessary to escape Earth orbit, the conclusion that a multistage rocket would be needed to accomplish this, and a design for such a rocket and even the airlocks that would permit a space traveler to pass from that vehicle into the vacuum of interplanetary space.
