The four clinical trials selected in this systematic review are conducted by Cortes, et al. (2009),
Martin, et al. (2011), Chia, et al (2006), and Stickeler, et al (2009).
3.2. Quality of the Included Studies
From the result of this quality assessment, all 4 studies were defined as good quality studies, and can
be seen in the table below:
Table 1: Results of Quality assessment for the four studies.
Chia,
Cortes, Stickeler,
Criteria
et al
et al
et al
1. Was the research question or objective in this paper
Yes
Yes
Yes
clearly stated?
2. Was the study population clearly specified and
Yes
Yes
Yes
defined?
3. Was the participation rate of eligible persons at least
Yes
Yes
Yes
50%?
4. Were all the subjects selected or recruited from the
same or similar populations (including the same time
period)? Were inclusion and exclusion criteria for being
Yes
Yes
Yes
in the study prespecified and applied uniformly to all
participants?
5. Was a sample size justification, power description, or
Yes
Yes
No
variance and effect estimates provided?
6. For the analyses in this paper, were the exposure(s) of
Yes
Yes
Yes
Martin,
et al
Yes
Yes
Yes
Yes
Yes
Yes