What did the committee discuss regarding the stratification of the recommendation by age?
The committee discussed at length the stratification of the recommendation by age, including the biological plausibility of the finding that NP monitoring had a differential effect depending on age. The committee suggested that the metabolism of NPs may change with age, and this could make NP monitoring less useful in older patients. The committee also agreed that age could be a surrogate for comorbidity, and this could explain the benefit of a more aggressive NP monitoring strategy in younger people (i.e. with fewer comorbidities). Supporting this hypothesis, one of the existing meta-analyses conducted a post-hoc analysis suggesting that the reduced mortality associated with NP monitoring was primarily seen in patients without previous cerebrovascular accident/transient ischemic attack, diabetes or COPD, and that the benefit of NP monitoring was absent in patients with any one of those comorbidities. Peripheral vascular disease was also found to be a relevant comorbidity explaining some of the association between the treatment affect and age.