ARTICLES
people who did not have NDE had become more
emotionally affected, and in some, fear of death had
decreased more than at 2-year follow-up. Their interest
in spirituality had strongly decreased. Most patients who
did not have NDE did not believe in a life after death at
2-year or 8-year follow-up (table 5). People with NDE
had a much more complex coping process: they had
become more emotionally vulnerable and empathic, and
often there was evidence of increased intuitive feelings.
Most of this group did not show any fear of death and
strongly believed in an afterlife. Positive changes were
more apparent at 8 years than at 2 years of follow-up.
In a study of mortality in patients after resuscitation
outside hospital,18 chances of survival increased in
people younger than 60 years and in those undergoing
first myocardial infarction, which corresponds with our
findings. Older people have a smaller chance of cerebral
recovery after difficult and complicated resuscitation
after cardiac arrest. Younger patients have a better
chance of surviving a cardiac arrest, and thus, to
describe their experience. In a study of 11 patients after
CPR, the person that had an NDE was significantly
younger than other patients who did not have such an
experience.19 Greyson7 also noted a higher frequency of
NDE and significantly deeper experiences at younger
ages, as did Ring.1
Discussion
Our results show that medical factors cannot account
for occurrence of NDE; although all patients had been
clinically dead, most did not have NDE. Furthermore,
seriousness of the crisis was not related to occurrence or
depth of the experience. If purely physiological factors
resulting from cerebral anoxia caused NDE, most of our
patients should have had this experience. Patients’
medication was also unrelated to frequency of NDE.
Psychological factors are unlikely to be important as fear
was not associated with NDE.
The 18% frequency of NDE that we noted is lower
than reported in retrospective studies,1,8 which could be
because our prospective study design prevented self-
selection of patients. Our frequency of NDE is low
despite our wide definition of the experience. Only 12%
of patients had a core NDE, and this figure might be an
overestimate. When we analysed our results, we noted
that one hospital that participated in the study for nearly
4 years, and from which 137 patients were included,
reported a significantly (p=0·01) lower percentage of
NDE (8%), and significantly (p=0·05) fewer deep
experiences. Therefore, possibly some selection of
patients occurred in the other hospitals, which
sometimes only took part for a few months. In a
prospective study17 with the same design as ours, 6% of
Good short-term memory seems to be essential for
remembering NDE. Patients with memory defects after
prolonged resuscitation reported fewer experiences than
other patients in our study. Forgetting or repressing
such experiences in the first days after CPR was unlikely
to have occurred in the remaining patients, because no
relation was found between frequency of NDE and date
of first interview. However, at 2-year follow-up, two
patients remembered a core NDE and two an NDE that
consisted of only positive emotions that they had not
reported shortly after CPR, presumably because of
memory defects at that time. It is remarkable that people
could recall their NDE almost exactly after 2 and
8 years.
Unlike our results, an inverse correlation between
foreknowledge and frequency of NDE has been
shown.1,8 Our finding that women have deeper
experiences than men has been confirmed in two other
studies,1,7 although in one,7 only in those cases in which
women had an NDE resulting from disease.
The elements of NDE that we noted (table 2)
correspond with those in other studies based on Ring’s1
classification. Greyson20 constructed the NDE scale
differently to Ring,1 but both scoring systems are
strongly correlated (r=0·90). Yet, reliable comparisons
are nearly impossible between retrospective studies that
included selection of patients, unreliable medical
records, and used different criteria for NDE,12 and our
prospective study.
Our longitudinal follow-up research into trans-
formational processes after NDE confirms the
transformation described by many others.1–3,8,10,13–16,21
Several of these investigations included a control group
to enable study of differences in transformation,14 but in
our research, patients were interviewed three times
during 8 years, with a matched control group. Our
findings show that this process of change after NDE
tends to take several years to consolidate. Presumably,
besides possible internal psychological processes, one
reason for this has to do with society’s negative response
to NDE, which leads individuals to deny or suppress
their experience for fear of rejection or ridicule. Thus,
social conditioning causes NDE to be traumatic,
although in itself it is not a psychotraumatic experience.
As a result, the effects of the experience can be delayed
for years, and only gradually and with difficulty is an
NDE accepted and integrated. Furthermore, the
longlasting transformational effects of an experience that
lasts for only a few minutes of cardiac arrest is a
surprising and unexpected finding.
63 survivors of cardiac arrest reported
a
core
experience, and another 5% had memories with features
of an NDE (low score in our study); thus, with our wide
definition of the experience, 11% of these patients
reported an NDE. Therefore, true frequency of the
experience is likely to be about 10%, or 5% if based on
number of resuscitations rather than number of
resuscitated patients. Patients who survive several CPRs
in hospital have a significantly higher chance of NDE
(table 3).
We noted that the frequency of NDE was higher in
people younger than 60 years than in older people. In
other studies, mean age at NDE is lower than our
estimate (62·2 years) and the frequency of the
experience is higher. Morse10 saw 85% NDE in children,
Ring1 noted 48% NDE in people with a mean age of
37 years, and Sabom8 saw 43% NDE in people with a
mean age of 49 years; thus, age and the frequency of the
experience seem to be associated. Other retrospective
studies have noted a younger mean age for NDE:
32 years,9 29 years,6 and 22 years.11 Cardiac arrest was
the cause of the experience in most patients in Sabom’s8
study, whereas this was the case in only a low percentage
of patients in other work. We saw that people surviving
CPR outside hospital (who underwent deeper NDE
than other patients) tended to be younger, as were those
One limitation of our study is that our study group
were all Dutch cardiac patients, who were generally
older than groups in other studies. Therefore, our
frequency of NDE might not be representative of all
cases—eg, a higher frequency could be expected with
who survived cardiac arrest in
a
first myocardial
infarction (more frequent NDE), which indicates that
age was probably decisive in the significant relation
noted with those factors.
THE LANCET • Vol 358 • December 15, 2001
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