B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
Bernd Grosche Federal Office for Radiation Protection, Germany
The work was carried with the support from the Grant agreement no 323310 (SEMI-NUC) with the EU under the EURATOM FP7 Programme
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• NIIRME, Semey, Kazakhstan • NNC, Kurchatov, Kazakhstan • NIRS, Chiba, Japan • IARC, Lyon, France • BfS, Neuherberg, Germany and • REA, Tokyo, Japan
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• Assumption: 2 cohorts – “historical cohort”, set up by NIIRME – “new cohort”, established by NNC with financial
support from the Japanese Radiation Effects Association (REA). The data from the latter are owned by REA and held by NIRS.
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
Settlement Settlement Settlement Settlement Settlement
Dolon Irtyshsk Semenovka Lokot others
Znamenka Shcherbakty Sosnovka Novopokrovka unknown
Kainar Bolshaya Vladimirovka Izvestka Akbulak
Karaul Mostik Besterek Aigyrjal (Kaskabulak)
Kenes Cheremushki Sarzhal Tailan (Kundyzdy)
Kenjekol Budene Semipalatinsk Bobrovka
Jana-aul Malaya Vladimirovka Kurchatov Isa
Kachiry Kanonerka Pavlodar Tarkhanka
Zhelezinka Semiyarka
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• NIIRME not only holds the historical cohort but a registry of 145,306 individuals (with personal identifiers) considered as being affected by the atomic bomb testing, according to Kazakh governmental legislation
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• register includes individuals being considered as affected by the testing since 1949 as well as their offspring.
• Follow-up of individuals included in the register is conducted on an annual basis – mortality – since 2002 also incidence data
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• Evaluation of individual identifiers • Testing possibilities of record linkage between the two
cohorts • Evaluation of uncertainties in individual record linkage • Establishing SOP document for future merging of the
two cohorts • Decision on data ownership, data access and data
storage
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
NIIRME (file: All_people.xls) NNC (file: person_.xls) Variable Name Description Variable Name Description sysid Random numbers identifying cohort members person_Id Random numbers identifying cohort members
firstname Individual's first name name Individual's first name lastname Individual's last, or family name. Multiple
records exist for individuals who experienced name changes, especially women
fam1-fam4 Individual's last, or family name. Multiple records exist for individuals who experienced name changes, especially women
midlname Individual's patronymic name otch Individual's patronymic name Gender Specifies an individual's sex as male or
female sex Specifies an individual's sex as male or female
birthdt Date of birth for each individual birth_dt Date of birth for each individual
deaddt Date of death death_dt Date of death icd9 Cause of death from international
classification of disease coding, revision 9 PlaceName Individual's settlement of residence local_no A number indexing an individual's location
(settlement) during a specified time period: this number must be linked to a second file to obtain the name of the location (localtable_.xls)
StartDate Start date of period that an individual lived in a settlement
mother_id person_Id of individual's mother, if available
EndDate End date of period that an individual lived in a settlement
father_id person_Id of individual's father, if available
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• linkage exercise based on the two large data sets
• Random sample of 3,000 individuals from each of the data sets
• Using RecLink3 software
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• The structure of individuals is different in the two registries – The NIIRME registry has a person-period
structure (multiple records per person for each period of observation)
– while NNC has a person-level structure (one record per person with multiple time periods)
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
Variable Type Reliability individual ID display n/a First name name 5 Last name name 2 Patronymic name name 3 sex number 6 birth year code 6 birth day display n/a birth month display n/a
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• This criteria yields 45 matches among the 3,000 total records. Based on these records, we conclude the following: – matches that receive a probability above 90%
appear to be true matches; – matches between 75%-89% are possible
matches; – matches below 75% seem unreliable
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• To check whether matches between 75%-89% probably are true matches, it would be necessary to conduct inspection of each individual record.
• Further information that could aid in this task are second or third last name records, as well as settlement records.
• However, settlement is time varying, and substantial work would be required to go through the datasets to identify an individual’s location at the time of relevant bomb testing.
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• Because of the different structures of the data bases, one would be required to link across multiple datasets and identify the time period at which an individual was at a settlement of interest.
• A complete linkage of both data bases is possible, but will be very work intensive. It is estimated that 1 person-year would be needed for a complete linkage.
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• NIIRME data set belongs to NIIRME, is continuously updated, and is open for Kazakh researchers on demand.
• NIIRME wishes to make this data set also available to a broader scientific community – include the respective information into the STORE platform
(http://storedb.org). This work is in progress.
• REA confirmed that the data from the “new cohort” may be used in the frame of SEMI-NUC related research
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• The NIIRME register is a good resource for future cohort studies.
• Focus on individuals from the exposed settlements (zones of “extraordinary” and “maximal” radiation risk)
• Information from historical cohort: – Number of study subjects, duration of follow-up and
dose range (0 to > 600 mGy) sufficient for risk analyses. – Mean dose <100 mGy makes the population of high
interest for today’s research.
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• More information is needed to better understand the construction of the NIIRME register.
• Population from any comparison area should not be used – previous analyses showed a large difference in the baseline risks
between the respective areas (Bauer et al., 2005, for cancer and Grosche et al., 2011, for cardiovascular diseases, respectively).
• Using NNC data might help in case missing information in the NIIRME data base needs to be filled.
• Links to other activities related to SNTS should be tightened.
B. Grosche, SEMI-NUC, Munich, Nov. 2015 SEMI-NUC
• 23,960 families in the registry • 13,692 families with information on 2nd
generation • 10,268 families with information on 3rd
generation