Case series‡	Elster, 40 2009	Miller and Miller 42 2009	Stewart, 44 2012	Miller and Benfield, 43 2008	Wiberg and Wiberg, 45 2010	Davies and Jamison, 39 2007	Marchand and Miller, 41 2009
1. Question clearly stated?	Yes	Yes	No	Yes	Yes	Yes	Yes
2. Population clearly described?	No	Yes	No	Yes	Yes	Yes	CD
3. Were cases consecutive?	CD	Yes	CD	Yes	Yes	Yes	CD
4. Were subjects comparable?	CD	Yes	CD	Yes	Yes	Yes	CD
5. Intervention clearly described?	No	No	No	No	No	Yes	No
6. Outcomes consistent and appropriate across all participants?	No	No	No	No	No	No	No
7. Follow-up adequate?	CD	CD	No	CD	No	CD	CD
8. Statistics described and appropriate?	No	NA	Yes	Yes	CD	NA	NA
9. Results clear?	No	Yes	No	Yes	No	No	No
Quality assessment	Low	Mod	Low	Mod	Mod	Mod	Low