Table 2 Methodological Quality Scoring¹ for all studies

Checklist item

1.[12]

2.[13]

3.[14]

4.[15]

5.[16]

6.[17]

7.[19]

8.[18]

1

Is there a rationale for the study?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

2

Is a clear study objective/goal defined?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

3

Are key elements of study design described (e.g. how were participants identified/recruited)

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

4

Are the setting and selection criteria for the study population described?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

5

Is the follow-up period appropriate?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

6

Are there any strategies to avoid loss to follow-up, or address missing data?

No

No

No

No

Yes

No

No

No

7

Is the sample size justified?

No

No

No

No

No

No

No

No

8

Is information presented about the measurement instruments used to measure the prognostic variable(s)

and does this enable replication (through the use of standardised or valid measures)?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

9

Is the outcome selected and assessed appropriately?

Yes

Yes

No

No

Yes

No

Yes

Yes

10

Are the study sample described (demographic/clinical characteristics)?

Yes

Yes

Yes

Yes

Yes

No

Yes

Yes

11

Is the final sample representative of the study's target population?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

12

Is loss to follow-up ≤ 20%? (If not, are there any significant differences between responders

and non-responders to follow-up on baseline variables? If yes, have the implications been considered?)

Yes

Yes

No 28%

Yes

Yes

Yes

Yes

Yes

13

Are the main results reported (including prevalence of prognostic indicator(s) & outcome, strength of association,

and statistical significance)?

Yes

Not fully

Not fully

Not fully

Yes

Not fully

Yes

Yes

14

Is the statistical analysis appropriate and described?

Yes

No

Yes

Yes

Yes

No

Yes

Yes

15

Were potential confounders and effect modifiers identified and accounted for (e.g. multivariate analysis)?

Yes

No

Yes

Yes

Yes

No

Yes

Yes

16

Do the findings support the authors' interpretations?

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

17

Do the authors discuss study limitations (e.g. biases/generalisability)?

Yes

Yes

Yes

No

Yes

No

Yes

No

Total Score

15

12

12

12

16

8

15

14