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FRA-LIL: Lille/PRIME Study Contributors from the MPC: Philippe Amouyel and Annie Bingham

© National Institute for Health and Welfare and the MORGAM Project investigators Last updated: 18 November 2005 For more information, please contact Kari Kuulasmaa (firstname.lastname@thl.fi)

Contents

• Cohort identification
• Cohort recruitment and the baseline examination
• End-points followed up
• End of follow-up period
• Follow-up procedures
• Diagnostic procedures
  • at baseline
  • during follow-up
• References
• Updates

Cohort identification

• Country: France
• MPC: 59 - PRIME/Lille
  • Administrative centre: INSERM U508-Institut Pasteur de Lille
  • Key personnel: Philippe Amouyel (Principal Investigator), Michèle Montaye, Brigitte Lemaire, Stéphanette Beauchant, Dominique Cottel, Catherine Graux, Nadine Marecaux, Chantal Steclebout, Sabine Szeremeta
• RUs: 
  • 01: Lille. A group of 86 towns in northern France. The area is urban, tertiary sector, with declining textile industries. The population is characterized by low socio-economic status, high mortality and high unemployment.
• RUAs:
  • FRA-LILa
• Cohorts: 
  • Cohort 21: 50-59 years old men from the RUs, who were examined in the baseline survey in 1991-1993.

Cohort recruitment and the baseline examination

The target was to recruit 2500 men aged 50-59 years. The cohort was recruited to broadly match the social class structure of the background population. The recruitment was based firstly on industry and various employment groups, excluding those with more than 10% of their workforce of foreign origin. Secondly the recruitment was based on health screening centres. This provided the opportunity to recruit unemployed and retired persons to the cohort. Eligible subjects were contacted by letter stating the aim of the study and asking to agree to an annual follow-up. The size of the cohort is 2633 men. Two thirds of them were recruited at a health screening centre and one third through occupational medicine.

The baseline examinations were carried out in 1991-1994. The PRIME baseline procedures are described in reference [1].

DNA are available for the members of the Cohort.

End-points followed up

• Deaths: yes
• Definite non-fatal MI: yes
• Possible non-fatal MI: no
• Unstable angina pectoris: yes
• Silent MI: no
• Cardiac revascularization: yes
• Stable angina pectoris: yes
• Non-fatal stroke events: yes
• Thromboembolic events: no

End of follow-up period

• Fatal events: Five years after the date of examination of each person
• Non-fatal events: Five years after the date of examination of each person

Follow-up procedures

Sources of data

• Person himself
• Relatives
• General practitioner, specialist or occupational medicine department
• Municipal corporation of the place of birth of the person: This is a source of information on the vital status of the person.

Procedure

Each year, on the anniversary of the initial examination, each subject was followed-up by means of a questionnaire sent to his home. Some of the answers to this questionnaire led to further enquiry.

The procedure for contacting the subjects was:

1. Mail an Annual Follow-up Questionnaire, the letter of introduction and a stamped pre-addressed envelope, on the anniversary of the initial PRIME examination.
2. Remail if no reply is received within 5 weeks.
3. If there is still no answer try to make contact by telephone.
4. If all this fails, contact:
   • his doctor(s) (general practitioner and/or specialist)
   • his Occupational Medicine Department
5. If this is unsuccessful make a home visit and, if necessary, talk to neighbours.
6. If still no information:
   • after 6 months have elapsed repeat from step 2 onwards
   • after 12 months try again
7. If no answer is obtained, contact the city hall of the town where the subject was born to verify that he is still alive.
8. If the person is alive, classify him as "lost to follow-up".
9. After 5 years try to establish if the subject is alive or dead. Write to the city hall of the town where the subject was born.

Whenever there was suspicion of an event, clinical information was sought directly from the hospital or general practitioner notes. All details of electrocardiograms, hospital admissions, enzymes, surgical operations, angioplasty, treatment etc. were collected. Death certificates, which were only available for subjects still living in the Urban Community of Lille at the time of the death, were checked for supporting clinical and post-mortem information on cause of death. Whenever necessary, the circumstances of death were obtained from the practitioner or the family.

Diagnostic procedures

At baseline:

• History of MI
  • Documented: The MPC systematically searched for all available information (patient records, procedure reports, etc.) each time a subject mentioned a history of any type of CHD in the items of medical questionnaire or indicated the use of medication for CHD. Subjects were then classified into 5 (0 to 4) categories by the PRIME Medical Committee and a relevant ICD-9 code was assigned: 0=no CHD, 1=history of MI (410, 412), 2=CHD, without MI (413, 414), 3=angina pectoris by Rose' questionnaire (see below), 4=major or moderate Q wave in ECG at baseline. Persons with code 1 were considered having a documented history of MI or unstable angina pectoris.
  • Self-reported:  An affirmative answer for the question "Have you ever been told by a doctor that you have had a myocardial infarction (heart attack)?" was considered as self-reported history of MI.
  • ECG: Persons with Minnesota code 1-1 or 1-2 (except 1-2-6) in baseline ECG were considered having an ECG change indicating myocardial infarction (PRIME code 4).
  • Rose questionnaire: As specified in item HISMI4 of MORGAM Form 21.
• History of cardiac revascularisation:
  • Documented: data not available
  • Self-reported: An affirmative answer for either or both of following questions: "Have you ever had a dilatation or unblocking of one or more coronary arteries (angioplasty)?" and "Have you ever had coronary artery surgery (by-pass, etc...)?" was considered as self-reported history of cardiac revascularization.
• History of angina pectoris:
  • Documented: See documented history of MI. Persons with PRIME code 2 and ICD-9 code 413 were considered having a documented stable angina pectoris.
  • Rose questionnaire: As specified in item HISAP2 of MORGAM Form 21, but omitting Questions 6 and 7 (PRIME code 3).
  • Self-reported:  An affirmative answer to the question "Have you ever been told by a doctor that you have had angina?" was considered as self-reported history of angina pectoris.
• History of coronary heart disease, type unspecified: Persons with self-reported history of MI, AP or cardiac revascularization or with PRIME code 2 and ICD-9 code 414 (see documented history of MI) were considered having a coronary heart disease, type unspecified.
• History of stroke:
  • Documented: The procedure was in essence the same as for CHD. Documentation was searched  each time a subject mentioned a  history of stroke in the items of medical questionnaire and the PRIME Medical Committee confirmed or rejected the previous stroke after reviewing all available information. For confirmed strokes a relevant ICD-9 code was assigned. Persons with an ICD-9 code between 430 and 438 were considered having a documented history of stroke.
  • Self-reported: An affirmative answer to an option "Carotid arteries or arteries of the neck" under the question "Have you had any arterial disease involving the following arteries? was considered as self-reported history of stroke.
• History of Diabetes: An affirmative answer to the question "Have you ever been told by a doctor that you had diabetes or threatened diabetes?" was considered as history of diabetes.

During follow-up:

• Deaths: The PRIME "Deaths" Medical Committee assigned the underlying cause of death using all available information from the death certificate, from the autopsy report  and from the general practitioner's, hospital and emergency team's notes. The code was used for the item DEATHDU of MORGAM Form 25. The causes of death from the death certificate were used for the items DEATHDA, DEATHDB and DEATHDC of MORGAM Form 25.
• CHD events: The PRIME Medical Committee independently validated the suspect coronary events using all medical information (see Follow-up procedures above) and assigned a code for each according to a strict protocol. The MORGAM diagnostic category was derived from this according to the following table:

  PRIME Code	PRIME Definition	MORGAM DGNCAT
  31- Myocardial infarction (MI)	Myocardial infarction was defined by one of the following sets of conditions: (1) new diagnostic Q wave or other fresh typical electrocardiographic sign of necrosis; (2) typical or atypical pain symptoms and new (or increased) ischaemia and myocardial enzyme levels higher than twice the upper limit; (3) post-mortem evidence of fresh myocardial infarction or thrombosis.	1=definite MI
  41-Definite coronary death	Definite coronary death was defined as death with a documented coronary event or as sudden death occurring within one hour following symptoms, when significant coronary atheroma was present at autopsy.	2=possible MI or coronary death
  42-Possible coronary death	When a coronary death was suspected, with no other documentation or explanation, it was labelled possible coronary death	5=unclassifiable
  43-Sudden death	Sudden death was defined as death occurring within one hour following symptoms without explanation.
  12-Unstable angina	Unstable angina was defined as a crescendo pain (change in frequency or severity of chest pain on exertion or appearance of chest pain at rest following pre-existing pain on exertion) or chest pain at rest, with either enzyme changes or electrical changes and one of the following criteria: (1) angiographic stenosis over 50%; or (2) a positive scintigraphy (if no angiographic data); or (3) positive exercise stress test (if no angiographic or scintigraphic data); or (4) electrocardiogram changes at rest (if no angiographic, scintigraphic or exercise stress test data),  but without myocardial infarction and no evidence of a non-coronary cause in the clinical history.	4=unstable angina pectoris
  11-Effort angina	Pain only on effort (not at rest and not crescendo) and one of the following criteria: (1) angiographic stenosis over 50%; or (2) a positive scintigraphy (if no angiographic data); or (3) positive exercise stress test (if no angiographic or scintigraphic data); or (4) electrocardiogram changes at rest (if no angiographic, scintigraphic or exercise stress test data),  but without myocardial infarction and no evidence of a non-coronary cause in the clinical history.	8=irrelevant (EVTYPE=1)
  In PRIME, there is no code for those who do not classify into the PRIME category of MI or angina		7=no MI

  Coronary events occurring within 28 days of each other were considered as one event.

• Stroke events: The PRIME Medical Committee independently validated the suspect stroke events using all medical information (see Follow-up procedures above). For each  event where stroke could not be excluded, a PRIME code, specifying the subtype, as well as a three-digit ICD-9 code was given according to the MONICA protocol.

  Stroke events occurring within 28 days of each other were considered as one event.

References

1. Yarnell JW. The PRIME study: classical risk factors do not explain the severalfold differences in risk of coronary heart disease between France and Northern Ireland. Prospective Epidemiological Study of Myocardial Infarction. Q J Med. 1998;91:667-76.

Updates to this document

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