Did the study address a clearly focused issue? | Y | Y | Y | Y | Y | Y | N | Y | Y | Y | Y | Y | Y |
Was the cohort recruited in an acceptable way to minimise selection bias? | NA | Y | Can’t tell | NA | N | Y | NA | NA | NA | NA | Y | Y | NA |
Was the exposure and outcome accurately measured to minimise bias? | Y | Y | Can’t tell | Can’t tell | N | Y | Can’t tell | Y | Y | Y | Y | Can’t tell | Y |
Have the authors identified all important confounding factors? | Y | Can’t tell | Can’t tell | Y | N | Can’t tell | N | Y | Y | Y | Y | Y | Y |
Have the authors taken confounding factors into account in the design and/or analysis? | Y | N | Can’t tell | Can’t tell | N | N | Can’t tell | Y | Y | Y | Y | Y | Y |
Was the follow up of subjects complete and long enough? (Not relevant for all studies) | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
Were the results precise? | Y | Y | Can’t tell | Y | Can’t tell | Y | N | Y | Y | Y | Y | Y | Can’t tell |
Do you believe the results? | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Can the results be applied to the local population? | Y | N | Y | Y | N | Y | N | Y | Y | Y | Y | Y | Y |
Do the results of this study fit with other available evidence? | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
Total score /10 | 8/10 | 6/10 | 4/10 | 6/10 | 3/10 | 7/10 | 2/10 | 8/10 | 8/10 | 8/10 | 9/10 | 8/10 | 7/10 |