Study
Allocation sequence generation Allocation concealment
Blinding
Lost to follow-up Calculation of sample size
Statistical analysis
Level of quality ITT analysis
Jonathan 1998
B
A
A
1
Yes
ANOVA Fisher’s exact test
B
Yes
Knorr 1998
A
A
A
2
Yes
ANOVA Shapiro-Wilks test Cochran-Mantel-Haenszel test
A
Yes
Noonan 1998
A
A
A
0
Yes
ANOVA Fisher’s exact Cochran-Mantel-Haenszel test Tukey’s modified linear trend test (stepwise trend test)
A
Yes
Malmstrom 1999
A
A
A
13
Yes
ANOVA Dunnet–Tamhane approach, Shapiro–Wilk statistic,Levene test
A
No
Meltzer 2000-1
A
A
A
4
Yes
ANOVA Fisher exact test Cochran-Mantel-Haenszel test;
A
No
Meltzer 2000-2
A
A
A
4
Yes
ANOVA Fisher exact test Cochran-Mantel-Haenszel test;
A
No
Anjuli 2002-1
A
A
A
3
Yes
ANOVA Wilcoxon rank sum test
A
Yes
Anjuli 2002-2
A
A
A
3
Yes
ANOVA Wilcoxon rank sum test
A
Yes
Baumgartner 2003 A A A NA Yes ANOVA A Yes
CarlosE 2003 A A A 0 Yes ANOVA A Yes
YildirimI 2004 A A B 0 Yes Mann–Whitney U-test B No
Charles 2006
A
A
A
NA
Yes
Huber-White variance; Linear and logistic regression models
A
Yes
Shah 2006 A A A 0 Yes ANOVA A Yes
Bisgaard 2009 B B A 0 Yes Fisher’s exact test B No
Bruce 2010-1 B B C 9 Yes NA§ C No
Bruce 2010-2 B B C 13 Yes NA§ C No