Table 1.

Quality assessment of controlled intervention, observational cohort and cross‐sectional studies

	Sun et al.18	Snow et al.17	Cho et al.26	Hartwich et al.23	St Peter et al.19	Moore et al.7	Toki et al.24	Stewart and Matheson25
1. Was the research question or objective in this paper clearly stated?	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
2. Was the study population clearly specified and defined?	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
3. Was the participation rate of eligible persons at least 50%?	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
4. Were all the subjects selected or recruited from the same or similar populations? Were inclusion and exclusion criteria for being in the study prespecified and applied uniformly to all participants?	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
5. Study described as randomized?	Yes	Yes	No	No	Yes	No	No	No
6. Randomization method adequate?	Yes	Yes	n.a.	n.a.	Yes	?	n.a.	n.a.
7. Was the treatment allocation concealed (so that assignments could not be predicted)?	No	No	n.a.	n.a.	Yes	?	n.a.	n.a.
8. Were study participants and providers blinded to treatment group assignment?	No	No	n.a.	n.a.	Yes	?	n.a.	n.a.
9. Were the people assessing the outcomes blinded to the participants' group assignments?	No	No	n.a.	n.a.	Yes	?	n.a.	n.a.
10. Were the groups similar at baseline on important characteristics that could affect outcomes (e.g. demographics, risk factors, co‐morbid conditions)?	Yes	Yes	n.a.	n.a.	No	?	n.a.	n.a.
11. Was the overall dropout rate from the study at endpoint 20% or lower than the number allocated to treatment?	Yes	Yes	n.a.	n.a.	Yes	?	n.a.	n.a.
12. Was the differential dropout rate (between treatment groups) at endpoint 15% or less?	Yes	Yes	n.a.	n.a.	Yes	?	n.a.	n.a.
13. Was there high adherence to the intervention protocols for each treatment group?	Yes	Yes	n.a.	n.a.	Yes	?	n.a.	n.a.
14. Were other interventions avoided or similar in the groups (e.g. similar background treatments)?	No	No	n.a.	n.a.	Yes	?	n.a.	n.a.
15. Were the outcome measures (dependent variables) clearly defined, valid, reliable and implemented consistently across all study participants?	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
16. Were the outcome assessors blinded to the exposure status of participants?	No	No	No	No	No	?	No	No
17. Was loss to follow‐up after baseline 20% or less?	Yes	Yes	Yes	Yes	Yes	?	Yes	n.a.

n.a., Not available.