Monday, 16 January 2017

Cardiopulmonary Resuscitation for older people: the mirage of numbers

New England Journal of Medicine published a study in March 2013, promoted by a group of researchers from the American Heart Association. It was a study performed with a sample of 6,972 people over 64 years who had been discharged in the period 2000-2008 after having survived a cardiac arrest during hospitalization. According to the study, 58.5% of the patients were still alive one year after discharge from hospital. The results, however, were significantly worse in the subgroup of 84 years plus (49.7%) and those who had suffered severe neurological sequels (42.2%) or had been in a vegetative coma (10.2%). The conclusions of this study, therefore, are favourable for the practice of cardiopulmonary resuscitation (CPR) during the cardiac arrest of the elderly. GeriPal, a blog of geriatrics and palliative care represented them in the "icon-box" that you can see above.

In June of the same year, the NEJM itself published a couple of letters to the director stressing that the data presented by American Heart Association researchers, whilst true, were also misleading. In another "icon-box", GeriPal summarized the same results but viewed from a global perspective, which could be explained as follows: out of 100 people aged 64 and over who received CPR during hospitalization, 49 did not survive the resuscitation attempts and 34 died during the subsequent stay. This means that 83 of the patients (49 + 34) showed as discharged dead and therefore only 17 were discharged alive. Of the latter, 7 died before the end of the year, while 10 were still alive, some of them with moderate to severe neurological injuries. Note that 59% of the survival rate shown in the first “icon-box” appears to relate the 10 people who survived the first year of discharge with the 17 who were discharged alive.

The first title features "Among older people who have survived a CPR, almost 60% are still alive at the end of a year," while the second title with data extracted from the same study, says: "Among the elderly who have received CPR, the survival rate for the year is 10%". If, as a matter of fact, I have to go in and decide if I authorize, a priori, of CPR manoeuvres, I would like the data they showed me not to be manipulated with a deceptive game of denominators.

Jordi Varela

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