Table 2.

Quality assessment for case series according to the NIH criteria.

Criteria		Stripeli et al.[13], Grécia, 2008	Karatza et al.[21], Grécia, 2008	Flanagan et al.[20],  Inglaterra, 1997
		Yes/No/Othera	Yes/No/Othera	Yes/No/Othera
1.	Was the study question or objective clearly stated?	Yes	Yes	Yes
2.	Was the study population clearly and completely described, including a case definition?	Yes	Yes	Yes
3.	Were the cases consecutive?	NR	NR	NR
4.	Were the subjects comparable?	Yes	Yes	No
5.	Was the intervention clearly described?	Yes	Yes	Yes
6.	Were the outcome measures clearly defined, valid, reliable, and consistently implemented across all study participants?	Yes	Yes	Yes
7.	Was the follow-up duration adequate?	Yes	No	NA
8.	Were the statistical methods well described?	NA	NA	NA
9.	Were the results well described?	Yes	Yes	Yes

^aOther: CD=cannot determine; NA=not applicable; NR=not reported