CRD Summary: The authors concluded that sustained treatment with growth hormone improves several cardiovascular parameters in adults with chronic heart failure, but more randomised evidence is needed. Although these conclusions are supported by the data presented, they fail to reflect that, for a large majority of outcomes, the randomised studies found no evidence of benefit from growth hormone.

CRD Commentary: The objectives and inclusion criteria were clear. Relevant sources were searched and efforts were made to retrieve unpublished studies. Steps were taken to minimise error and bias in the validity assessment and data extraction by having more than one reviewer make decisions independently; however, it is not clear whether this also applied to the study selection process. Relevant quality criteria were considered, but few details about the individual studies were reported. The design of the open studies was not clear: these studies were apparently uncontrolled and it is unclear whether it was appropriate to pool their findings with the RCTs. The analyses based solely on RCTs seem more likely to be reliable, but it is difficult to interpret the clinical significance of the positive findings in view of the very large number of outcomes measured, the lack of pre-specified primary outcomes and the small sample sizes. It is also unclear whether the RCT-only analyses were statistically homogeneous. Although the authors’ conclusions are supported by the data presented, they fail to reflect that, for a large majority of outcomes, the randomised studies found no evidence of benefit from GH.