The majority of studies reviewed contained methodological weaknesses including; inappropriate study design, limited sample representativeness, the use of ecological data to evaluate individual behaviour change and failure to adequately control for potentially confounding variables.
Both suffered from major methodological weaknesses including very small sample sizes.
Both had important methodological weaknesses, including inadequate method of randomisation, visual estimation of blood loss for determining outcome measures, and limited sample sizes.
Most trials in this area are limited by methodological weaknesses including small sample sizes and short supplementation durations, ranging from eight weeks [ 18] to four months [ 19].
Further limitations to the existing evidence on admission and detention rates in the FEP population are methodological weaknesses including small sample sizes and poorly defined, at times meaningless, ethnic categorisations (often merging highly heterogeneous populations) thereby limiting generalisability.
These inconsistent findings may be due to the use of different measures of exposure and methodological weaknesses including self-reported measure of exposure, small samples (N=94 665) and selection or recall bias (refer to web appendix: Supplementary Table A1).
Methodological weaknesses included use of a 7-day diet history with the errors and inaccurateness associated with self-reported data, lack of blinding for participants and dietitians, and the attempt to demonstrate a dose response to nuts when the primary objective of establishing whether nuts improved glycemic control had not first been demonstrated.
It is imperative to acknowledge several potential limitations in our meta-analysis: (1) For the particularity of the clinical operation, the sample size of each trial was relatively small; (2) There were some differences in postoperative analgesia drugs and dosages; (3) There were some methodological weakness in all included RCTs.
Inter-study disagreement on the role of WHR in female attractiveness and the relative importance of WHR and BMI arguably results from methodological variation and weaknesses, including the use of schematic silhouette drawings of a poor realism or of photographs of real women without having controlled for all of the confounders.
We address areas of potential methodological weakness in such surveys, including sampling and questionnaire design, respondent biases, statistical analyses, and sensitivity of resultant inferences.
