Prevalence of near-death experiences in people with and without REM sleep intrusion

Abstract

Background The origin and prevalence of near-death experiences are unknown. A recent study suggested a link with REM sleep intrusion but was criticized for its selection of control participants. We therefore assessed the association of REM intrusion and near-death experiences with different methods. Methods Using a crowd-sourcing platform, we recruited 1,034 lay people from 35 countries to investigate the prevalence of near-death experiences and self-reported REM sleep intrusion. Reports were validated using the Greyson Near-Death Experiences Scale (GNDES) with ≥7 points as cut-off for near-death experiences. Results Near-death experiences were reported by 106 of 1,034 participants (10%; 95% CI [8.5–12%]). Evidence of REM intrusion was more common in people with near-death experiences (n = 50∕106; 47%) than in people with experiences with 6 points or less on the GNDES (n = 47∕183; 26%) or in those without such experiences (n = 107∕744; 14%; p = < 0.0001). Following multivariate regression analysis to adjust for age, gender, place of residence, employment and perceived danger, this association remained highly significant; people with REM intrusion were more likely to exhibit near-death experiences than those without (OR 2.85; 95% CI [1.68–4.88]; p = 0.0001). Discussion Using a crowd-sourcing approach, we found a prevalence of near-death experiences of 10%. While age, gender, place of residence, employment status and perceived threat do not seem to influence the prevalence of near-death experiences, we confirmed a possible association with REM sleep intrusion.

Prevalence of visual snow syndrome in the UK

“…We recruited an unprimed sample of adult laypeople (aged ≥ 18 years) from the UK matched for age, gender and ethnicity according to UK census data [17,18], using the online platform Prolific Academic (https://pro lific.ac/; Table 2). Like Amazon's Mechanical Turk, Prolific Academic is a crowdsourcing online platform to recruit human subjects that can be used for research purposes [19][20][21] and that compares favorably in terms of data quality, including honesty and diversity of participants [22]. Representative population samples from the UK and the USA (but no other countries) are available for an additional fee, i.e.…”

Migraine aura, a predictor of near-death experiences in a crowdsourced study

“…Like Amazon’s Mechanical Turk, Prolific Academic is a crowdsourcing online platform to recruit human subjects that can be used for research purposes (Kondziella, Dreier & Olsen, 2019; Kondziella, Cheung & Dutta, 2019) and that compares favorably in terms of data quality, including honesty and diversity of participants (Peer et al, 2017). Participants were recruited without any filters except for English language and age ≥18 years, and we excluded participants who had been enrolled in our previous study on NDE and REM intrusion (Kondziella, Dreier & Olsen, 2019). The study was announced under the headline “Survey on near-death experiences and headache” using the following text: “We wish to explore the frequency with which near-death experiences occur in the public.…”

“…From all participants, we collected information about age, gender, place of residence and employment status (data provided automatically by Prolific Academic); if they had frequent headaches; if yes, if these headaches could last longer than 4 hours and were associated with visual or non-visual aura (Kaiser et al, 2019); if participants ever had an NDE; if yes, if this experience occurred in a truly life-threatening situation or in a situation that just felt so; if the experience was neutral, pleasant or unpleasant; and all participants with an NDE were asked to provide information about all 16 items of the GNDES, the most widely used standardized tool to identify, confirm and characterize NDE in research (Greyson, 1983). Like in our previous study (Kondziella, Dreier & Olsen, 2019), NDE was defined by a GNDES score ≥7. Participants with an NDE (and those who claimed an NDE but scored 6 or less points on the GNDES) were also given the opportunity to describe this in their own words (optional).…”

“…Using a very high population size (300,000,000), a confidence level of 95% and a margin of error of 5%, we estimated the required sample size to be 384 participants. However, since previous studies have estimated the frequency with which NDE occur in the public to be 5-10%, including our own on NDE and REM intrusion (Kondziella, Dreier & Olsen, 2019), we decided to enroll approximately 1000 participants to identify an estimated number of 100 individuals with an NDE.…”

“…We countered this in our survey with a crowdsourced approach in which the control group originated from the same population as the NDE group (i.e. unprimed lay people) (Kondziella, Dreier & Olsen, 2019). Our survey was announced under the headline “Survey on Near-Death Experiences and (Related Experiences)”, but we did not provide further information about the content of the study.…”