The Hound of the Baskervilles effect: natural experiment on the influence of psychological stress on timing of death
BMJ 2001; 323 doi: https://doi.org/10.1136/bmj.323.7327.1443 (Published 22 December 2001) Cite this as: BMJ 2001;323:1443
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Editor--Phillips et al have uncovered a fascinating relationship
between the day of the month and the mortality rate for Chinese-Americans
and Japanese-Americans. There clearly is an increase in chronic heart
disease deaths of Chinese and Japanese on the fourth day of the month. The
authors attribute this to the similarity in the Chinese and Japanese
languages of the spoken words "death" and "four."
Have the authors considered whether days with a pleasurable
association might have a beneficial impact? Their analysis shows a
decrease in mortality for Chinese and Japanese on days twenty, twenty-six,
and possibly day twelve. Is there any resemblance, either spoken or
pictorially, between the words for those days and words evoking feelings
of relaxation, wellness, or happiness?
John H. Glaser
4 Woodpark Circle,
Lexington, MA 02421, USA
E-mail: glaserj@alum.mit.edu
Competing interests: No competing interests
To: The Editor
What's in a Word?
Phillips et al. reported elevated cardiac mortality on the 4th day of
the month for Chinese and Japanese Americans as a group, which may be
related to cultural ambiguity about number 4 because the words 4 and death
are homonyms. An interesting corollary might be whether this also applies
to the 4th hour (am/pm) and/or the 4th month of the year?
The Japanese language, however, has four alternative pronunciations
for 4 that are not homonymic--more accurately, homophonic--with death.
Accordingly, some Japanese practice linguistic "prevention" by avoiding
the anxiety-laden term insofar as possible. The Mandarin and Cantonese
speakers, apparently, have no such option. It might, therefore, be of
interest to ascertain whether there is a difference between the Chinese
and Japanese patients in terms of day 4 mortality.
One of the responders raised the interesting issue of Gregorian vs.
traditional calendars. It would seem, at a guess, that if the negative
connotation is tied to the number 4 alone, the nature of the calendar
would be immaterial.
Sincerely,
RB Worobec
Team Leader,
Medical Sciences & Biotechnology Team,
Library of Congress,
Washington, DC 20540
USA
Competing interests: No competing interests
Although a number of methodological issues should be considered
regarding this research paper, overall, if the findings are accurate, then
they probably do not surprise anybody. If we ask any member of the public
for their view, we are likely to receive the response, 'Of course unlucky
days are stressful'.
Perhaps the most important issue to have been raised by these
findings is that health practitioners may need to take beliefs and
superstitions into account when treating patients.
Competing interests: No competing interests
Another alternative, similar but different to ben Shlomo's, is as
follows. Philips and colleagues say: "It is unlikely that the fourth day
is objectively more hazardous than the six days surrounding it because no
increased mortality on the fourth was found in white controls." But in
these days of genetic medicine, the hypothesis might have been considered
that perhaps the fourth day is objectively more hazardous to Japanese and
to Chinese than to Europeans.
A further point which is difficult for me to understand as a Jew, is
that all dates with respect to which my people have religious or folk
beliefs about being unlucky or lucky or whatever, are dates in the Jewish
traditional lunar calendar. The Japanese and the Chinese also have
traditional calendars. It is surprising that they should have any beliefs
whatsoever about the fourth day of the Gregorian month.
Competing interests: No competing interests
In their briliant observation Phillips et al. documented an
association of higher rate of mortality from heart diseases in Chinese and
Japanese Americans during the 4th of every month. In their introduction
they refer to the traditional Chinese and Japanese "superstitious" affect
towards it. Philosophically, if not practically, one can not rule out the
possibility that the accumulating experience of these two large nations
gave solid reason to this belief. What if indeed some constituting,
traumatic events in the history of these nations took place on the fourth
of a given calender and the collective memory later perpetuated and
reinforced the effect.
Competing interests: No competing interests
In a large observational study David Phillips and co-workers note an
increase in cardiac mortality on the 4th of the month among Chinese and
Japanese Americans, which does not occur in white matched controls. This
increase is particularly marked for inpatient deaths from chronic heart
disease in California (figure 3). They link this observation to their
cultural-linguistic association of the number 4 with death.
This effect may well be real, but some important issues remain
unaddressed. The authors have addressed a hypothesis which to them
clearly relates to one specific day. To be really convincing, we need to
be sure that the day 4 mortality really should be regarded as an outlier,
relative to other dates, and this is not the foregone conclusion that
might be supposed. Directly from figure 3, the most extreme part of the
data, the 95% confidence interval for day 4 mortality overlaps the
intervals for most of the other dates. Moreover, the relevant rate
ratios, 1.07 for all cardiac deaths, 1.13 for chronic heart diseases, and
1.27 restricted to California, are presented with ordinary 95% confidence
intervals, but no p-values, in accordance with normal BMJ policy.
However, the one situation in which p-values are more directly informative
than the corresponding confidence intervals is when we are trying to
assess whether a striking observation might be merely a coincidence. For
cardiac mortality as a whole, the log rate ratio appears to be 0.068, with
standard error 0.021, and z=3.17, p=0.0015. (These figures are
reconstructed from the heavily rounded ones given, and hence are only a
crude approximation.) While a p-value of 0.0015 seems fairly extreme,
this relies heavily on starting with the hypothesis that it is the 4th of
the month that is different. A more conservative (i.e. more convincing to
sceptics) p-value involves a Bonferroni correction by a factor of 28 (the
number of days studied, which are common to all months), giving 0.043,
which though technically statistically significant is far from
extraordinary. It is true that when a similar process is applied to the
more extreme rate ratios of 1.13 and 1.27 above, they remain highly
significant. But it is commonly found that by restricting attention to
subgroups of the data, one can enhance the nominal statistical
significance in this way. It is far from clear whether it was a prior
hypothesis that this effect would be much more marked in California than
elsewhere.
The hypothesis set out by Phillips et al relates exclusively to
cardiac mortality, which conveniently squares with both the data presented
here and the Baskerville link. But if stress associated with this date is
so devastating to Chinese and Japanese, one would expect there would be a
marked effect on accidental and suicide deaths also, which do not appear
to have been examined.
Competing interests: No competing interests
Hound of the Baskervilles: Natural or statistical experiment?
In their paper “Psychology and survival” (The Lancet, 1993, vol. 342,
pp. 1142-1145) Phillips et al. examined the correlation between year of
birth and survival (average age of death, AAD) of Chinese Americans who
died of cancer, heart diseases and pulmonary diseases. They found that the
birth year of “fire” (years ending in 6 or 7), which is “bad” for heart,
does not make a significant change in AAD in the case of chronic ischaemic
heart disease (drop by only 0.14 years) but is more significant in acute
myocardial infarction (drop by 1.22 years), while in “all other heart
diseases” the AAD increases by 0.67 years.
Questions:
- Why does “bad” birth year not have a significant psychosomatic effect
in chronic heart diseases while the number of the day has?
An interesting statistical problem would be to superimpose the two
effects, i.e. birth year and day number. No question, any chinese
astrologist has the answer.
- Have the authors studied the effect of “Day 4” on other sources of
death (cancer etc)?
Also, in case that the birth year counts in the Baskerville effect,
some correction may be needed in this study, because the studied period
of 1973 – 1998 includes three pairs of “bad heart” years (1976-’77, ’86-
’87 and ’96-’97), three pairs of “bad liver” years, two and half pairs of
“bad tumour” years and two pairs of “bad lungs” years. I mean, that period
was (astrologically) worse for heart than for lungs.
George Argyrakos
Agronomist.
Athens, Greece
argyrakos@37.com
Competing interests:
None declared
Competing interests: No competing interests