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CHAPTER 7
Collecting All the Required Data from RERF
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In order to evaluate cancer-risk and dose-response from the
A-Bomb Study (1950-1982), we needed to assemble the raw data from
RERF. Since RERF had not published all of them, this task was not
routine. It involved four sets of source-material:
* (1)
The Written Technical Report (TR) :
-----------------------------------
The RERF Technical Report for the 1950-1982 cancer follow-up
is TR-1-86 by Preston and Pierce (Pr86). TR-1-86 is also called
Life Span Study (LSS) Report 10. An abbreviated version of TR-1-86
was published in the journal RADIATION RESEARCH in 1987 (Pr87a).
Analysts using these publications, however, need to avoid
three erroneous entries in their Table l:
ERROR No.1: Hiroshima subjects in the 1-9 kerma-rad
dose-category are given as 15,391. This is an error. The correct
number is 15,931.
ERROR No. 2: The mean dose for Hiroshima in the 300-399
kerma-rad dose-category is given as 364.4. This is an error. The
correct value is 346.4.
ERROR No. 3: The mean dose for Hiroshima in the 400+ kerma-rad
dose-category is given as 524.2. This is a small error. The
correct number is 524.4.
This book uses the correct numbers, of course; they will be
seen as entries in our special Table 26-H, which also comes from
RERF.
Welcoming Input from Readers :
------------------------------
In mentioning these slips in the the RERF report, we intend no
criticism. We certainly hope that anyone who notices such slips in
THIS book will inform us, so that we may correct them before
another printing and can thus prevent trouble for others who may
use our numbers "downstream." Other types of comment also are
welcome.
* (2)
The Corresponding Floppy Diskette :
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Most commendably, RERF has started to make available floppy
diskettes which contain far more data than do the written reports.
For the 1950-1982 follow-up, we used the RERF diskette entitled
"Cancer and Non-Cancer Mortality, R10ALL.DAT" (R-Ten-All). The
diskette reports the observations for the 91,231 A-bomb survivors
in the Life Span Study, but omits the "Not in City" or NIC group
(see Chapter 5).
On the diskette, the 1950-1982 data are arranged in 1,280 rows
of entries. The number 1,280 is the product of 2 cities, times 2
sexes, times 5 age-bands, times 8 dose-classes, times 8 four-year
follow-ups.
Except for Chapter 17 in this book, we always deal with the
aggregate or cumulative observations from 1950-1982. Therefore, we
have summed the entries for the eight separate follow-ups, and
this reduces the file from 1,280 to 160 rows, or subsets.
We have reproduced these 160 rows of raw data in this book's
Chapter 26 as Master Table 26-A,B,C,D as follows:
Table 26-A : Hiroshima Males (40 lines).
Table 26-B : Nagasaki Males (40 lines).
Table 26-C : Hiroshima Females (40 lines).
Table 26-D : Nagasaki Females (40 lines).
* (3) Previously Missing Data --
Persons, True Doses, True Ages ATB
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We (and other analysts) also need the actual numbers of
persons initially in each of the 160 subsets, their true mean
doses, and their true mean ages ATB. These three crucial types of
data are not provided on the RERF diskette.
We requested the missing data from RERF, and we received it as
nine printout sheets, which are reproduced in Chapter 26 as Tables
26-E through 26-M. This information is not available (as we go to
press) anywhere else in the literature. Except for reduction in
size and addition of some identifying titles, the sheets are
exactly what RERF provided (final version, August 29, 1988).
We would like to express our appreciation for the excellent
cooperation of Dr. Donald A. Pierce, who was Chief of RERF's
Department of Statistics at that time.
Initial Persons :
-----------------
The RERF diskette provides person-years (PYR), but not the
number of persons initially in each subset in 1950. Therefore the
persons in our Master Table 26-A,B,C,D come from the special
Tables 26-E through 26-M (where they are called "cases").
True Mean Doses :
-----------------
The diskette provides fictitious or nominal doses. It uses the
mean dose of an entire dose-group whether or not it really
describes a particular subset of that dose-group. Therefore, the
true mean kerma-doses in Master Table 26-A,B,C,D (Column G) were
added by us from the special Tables 26-E through 26-M.
True Mean Ages At-Time-Of-Bombing :
-----------------------------------
The diskette provides fictitious or nominal ages ATB. It uses
the midpoint of an age-band whether or not the midpoint really
describes a particular subset of that age-band. Therefore the true
mean ages ATB in our Master Table 26-A,B,C,D (Column D) were put
there by us from the special Tables 26-E through 26-M.
The data which we received from RERF, on the true mean ages
ATB, apply to RERF's customary eight dose-groups. It is easy to
see in Table 26-E (and even easier in Table 4-A) that true mean
age ATB is not the same in all eight dose-groups. In view of
RERF's new practice of subdividing Dose-Groups 2 and 3, the
following point deserves emphasis.
A Warning about Subdivision :
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If a dose-group is divided into halves (its lower dose-range
and its upper dose-range), its two cohorts will probably have
different mean ages. When Dose-Group 2 is divided, it is
impossible to predict whether the people falling into its lower
dose-range are younger, or older, than the people falling into its
upper dose-range. The same uncertainty exists about any division
of Dose-Group 3.
For the reasons explained in Chapter 11, and demonstrated in
Chapter 13, no analysis of risk or dose-response could be properly
done with subdivided groups in the absence of the necessary
adjustments for age-differences.
The problem does not arise in this book, because we use the
customary undivided dose-groups for which true age-data now have
been provided by RERF. In our judgment, the number of cancer cases
and the dosimetry in this database do not permit subdivision (see
Chapter 8, Part 4).
* (4) Missing Data for DS86 Subsets --
Neutron and Gamma Components of Dose
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Our approach to application of the new dosimetry was described
in Chapter 6. In order to use our approach, we needed to obtain
data which have not been published by RERF: The DS86 neutron and
gamma components for each subset of persons shown in RERF
Technical Report TR-12-87, Appendix Table 2 (Shi87).
We requested this information from J.W. Thiessen, M.D., the
Vice-Chairman of RERF and representative of the (U.S.) Department
of Energy, Office of Health and Environmental Research (Doe87,
p.xvii). He graciously provided it in December 1988.
The printouts from RERF are reproduced in Chapter 26 as our
Tables 26-N and 26-"O". Chapter 10 shows the steps which lead from
the special Tables 26-N and 26-"O" to the entries in Columns I
(Eye) and J of the Master Table 26-A,B,C,D.
A Word of Appreciation :
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RERF holds in trust, for humans everywhere, a unique database
of great importance for human health. With regard to the courtesy
and attention which RERF gives to meeting requests from outside
analysts, RERF sets a fine standard indeed for other research
institutions.
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