Table 2. Modified downs and black checklist.
Yes No
1. Is the hypothesis/aim/objective of the study clearly described? 1 0
2. Are the main outcomes to be measured clearly described in the Introduction or Methods section?If the main outcomes are first mentioned in the Result section the question should be answered no. 1 0
3. Are the characteristics of the subjects/animal/specimen included in the study clearly described?Inclusion and/or exclusion criteria should be given. 1 0
4. Are the main findings of the study clearly described?Simple outcome data should be reported for all major findings so that the reader can check the major analyses and conclusions. (This question does not cover statistical tests which are considered below.) 1 0
5. Does the study provide estimates of the random variability in the data for the main outcome?In non-normally distributed data the inter-quartile range of results should be reported. In normally distributed data the standard error, standard deviation or confidence intervals should be reported. If the distribution of the data is not described, it must be assumed that the estimates used were appropriate and the question should be answered yes. 1 0
6. Have actual probability values been reported (e.g. 0.035 rather than <0.05) for the main outcomes except where the probability value is less than 0.001? 1 0
7. If any of the results of the study were based on “data dredging”, was this made clear?Any analyses that had not been planned at the outset of the study should be clearly indicated. If no retrospective unplanned subgroup analyses were reported, then answer yes. 1 0
8. Were the statistical tests used to assess the main outcomes appropriate?The statistical techniques used must be appropriate to the data. For example nonparametric methods should be used for small sample sizes. Where little statistical analysis has been undertaken but where there is no evidence of bias, the question should be answered yes. If the distribution of the data (normal or not) is not described it must be assumed that the estimates used were appropriate and the question should be answered yes. 1 0
9. Were the main outcome measures used accurate (valid and reliable)?For studies where the outcome measures are clearly described, the question should be answered yes. For studies which refer to other work or that demonstrates the outcome measures are accurate, the question should be answered as yes. 1 0
10. Were the control trials from the same population group or were the control trials from other population group?If the reference conditions is from the same subjects/animal/specimen, the question should be answered yes. 1 0
11. Were study subjects measured over the same time period?If the rest time between the single conditions is the same, the question should be answered yes. 1 0
12. Were the trials randomized?If not reported, the question should be answered no. 1 0
13. Did the study have sufficient power to detect an important effect where the probability value for a difference being due to chance is less than 5%?If the necessary sample size was calculated before, the question should be answered yes. 1 0