Table 5.

GRADE summary of findings table - primary outcomes

*The risk in the intervention group (and its 95 % confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95 % CI).

CI confidence interval, RR risk ratio, OR odds ratio, DNR do not resuscitate, RCT randomized controlled trial

GRADE Working Group grades of evidence

High quality: we are very confident that the true effect lies close to that of the estimate of the effect

Moderate quality: we are moderately confident in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different

Low quality: our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect

Very low quality: we have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of effect

Justifications for grading

1. Half of studies are cohort studies of poor rather than good quality according to the Newcastle-Ottawa scale

2. Statistically significant heterogeneity; however, between large and small effects rather than between positive and negative effects

3. Only included DNR status recorded in the medical chart; may not have included those instances where life support is withdrawn and DNR status is assumed

4. One of the two included trials used cluster randomization, which have artificially narrowed the confidence interval; the resulting pooled estimate may thus be overly precise

5. Marked clinical heterogeneity between populations, confirmed with statistical heterogeneity, with inconsistent results crossing the line of no effect