northern finland 1966 birth cohort welfare and health
TRANSCRIPT
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Northern Finland 1966 Birth Cohort Welfare and Health Research Programme
Implementation of the field study
7 April 1997
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Contents
ABSTRACT
1 BACKGROUND AND AIMS OF THE STUDY ...................................................... 4
2 STUDY TOPICS TO BE COVERED ........................................................................ 5
3 FACILITIES ............................................................................................................... 5
4 STAFF......................................................................................................................... 5
5 SCHEDULE ................................................................................................................ 6
6 FIELD WORK ............................................................................................................ 6
6.1 Mailing of invitations and changes in schedule .................................................. 6
6.2 Field work in practice ......................................................................................... 7
6.2.1 Samples and examinations .......................................................................... 8
6.2.1.1 Health check-up sample .......................................................................... 8
6.2.1.2 OATTL sub-sample (appendix 14) ......................................................... 8
6.2.1.3 Psychiatric interview sub-sample (appendix 15) .................................... 9
6.2.1.4 Audiometry sub-sample .......................................................................... 9
6.2.1.5 Osteoporosis sub-sample ........................................................................ 9
6.2.1.6 Twin sub-sample ................................................................................... 10
6.2.2 Division of tasks between field team members ........................................ 10
6.2.3 Description of the most important field tasks ........................................... 12
6.2.3.1 Admission of the study subject, verification of identity and consent for
using the data ........................................................................................................ 12
6.2.3.2 Filling in the “Postal questionnaire” form ............................................ 12
6.2.3.3 Interviews .............................................................................................. 12
6.2.3.4 Filling in the “Questions about work” and “Pen computer questions”
forms 13
6.2.3.5 Measurement of heart rate .................................................................... 13
6.2.3.6 Measurement of blood pressure ............................................................ 13
6.2.3.7 Skin prick test (appendix 12) ................................................................ 14
6.2.3.8 Spirometry............................................................................................. 15
6.2.3.9 Measurement of waist and hip circumferences ..................................... 15
6.2.3.10 Measurement of height and body weight .......................................... 15
6.2.3.11 Measurement of physical performance capacity (appendix 13) ....... 16
6.2.3.12 “Opinions” form and collecting nail samples ................................... 16
6.2.3.13 Audiometry ....................................................................................... 17
6.2.3.14 Food and exercise diaries .................................................................. 17
6.2.3.15 Venous blood sample ........................................................................ 17
6.2.3.16 Processing of blood samples ............................................................. 18
7 PROCESSING OF DOCUMENTS AND SAMPLES, MAINTAINING
CONTACTS AND INFORMATION SERVICE ............................................................. 20
7.1 Study forms ....................................................................................................... 20
7.2 Dispatching of laboratory samples.................................................................... 20
7.3 Maintaining contacts ......................................................................................... 21
7.4 Information to the study subjects ...................................................................... 21
7.5 Information to the press .................................................................................... 22
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APPENDIXES
1. Examination facilities, addresses, telephone numbers and contact persons
2. Schedule by municipalities in the first stage
3. Field work teams
4. Persons in charge of the project and telephone numbers
5. Daily schedule
6. Example of the list of appointments*
7. Example of the sticker list
8. Invitation letter
9. Overall course of field work
10. Contacting the study subjects
11. Written material needed in the study
12. Procedure for skin prick test
13. Instructions for the measurement of physical performance capacity
14. Sub-sample of Oulu Regional Institute of Occupational Health (OATTL), selection
criteria
15. Scid interview, instructions for the field workers
*Appendixes are not available in English or contain personal information and are thus not
included in the version to be appear on the NFBC webpage.
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ABSTRACT
The Department of Public Health Science and General Practice, Faculty of Medicine,
University of Oulu, carries out the Northern Finland 1966 Birth Cohort Welfare and
Health Research Programme with several co-operative partners. About 10000 30-year-old
cohort members will be examined. The follow-up examinations will be carried out during
the year 1997 starting on 21 April in all municipalities of the provinces of Oulu and
Lapland. The aim of the project is to improve the well-being and health of the young
working age population especially in Northern Finland. The study consists of a postal
questionnaire and a health check-up by public health nurses. Height, weight, hip and
waist circumferences, blood pressure, heart rate, spirometry and physical performance
capacity will be measured in the health check-up using methods applicable for
epidemiological studies. Blood tests and allergy skin test are also included to the study
programme. In addition, some further information will be collected from the study
subjects and in interviews. There are also five different sub-samples in the field study:
Oulu Regional Institute of Occupational Health (OATTL), psychiatric interview,
osteoporosis, audiometry and twin sub-samples. The field study will be carried out by
professional nurses in municipal health centres or corresponding facilities. In this plan,
we have also described the field work in practice, processing of measuring results and
samples, and basic principles of information.
1 BACKGROUND AND AIMS OF THE STUDY
The Northern Finland 1966 Birth Cohort Welfare and Health Research Programme is a
continuation of an extensive cohort study started in 1966 by Professor Paula Rantakallio.
This birth cohort consists of the children who were due to be born in the provinces of
Oulu and Lapland in 1966. About 11200 of 12058 liveborn infants were alive and about
7200 still living in the area in March 1997. The data has been collected prospectively
since pregnancy and the data collection has been supplemented at the ages of 1 and 14
years by postal questionnaires and various registers. The cohort will undergo so called
“Northern Finland 1966 Birth Cohort Welfare and Health Research Programme” follow-
up examinations in 1997. At that time, the study subjects will be 30 years old. The study
consists of the postal questionnaire and the health check-up. All surviving members of
the cohort will be mailed a questionnaire. The cohort members living in the provinces of
Oulu and Lapland and a part of them living in other parts of Finland will be invited to a
health check-up.
The general aim of the study is to improve the health and well-being of the young
working age population. Risk factors connected with working and functional capacity,
social welfare and illnesses are aimed to be studied through previously collected data.
Data will be used for medical and public health studies that relate to causes and
prevention of illnesses.
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2 STUDY TOPICS TO BE COVERED
In the first stage, all the cohort members living in the provinces of Oulu and Lapland will
undergo the health check-up. There are about 7200 study subjects. A part of study
subjects living elsewhere in Finland will be examined in the second stage at the end of
the year 1997. Cohort members living elsewhere will receive only a postal questionnaire.
The study programme is divided into the following sections:
1. postal questionnaire (to all cohort members)
2. health check-up sample
3. sub-sample of OATTL
4. psychiatric interview sub-sample
5. audiometry sub-sample
6. osteoporosis sub-sample
7. twin sub-sample
3 FACILITIES
The study will be carried out mainly in municipal health centres or other corresponding
facilities allocated by the health centre. In the city of Oulu the empty ward number 11 of
the clinic of obstetrics and gynaecology in the Oulu University Hospital (OYS) will be
used for the purpose. The health centres and the Oulu University Hospital have been
asked to reserve two rooms for examinations, a room for taking and handling blood
samples, and a waiting room. The examination rooms will be used only by the field
workers while the sample room and the waiting room can be used for other corresponding
purposes, too. The rooms should be provided with the necessary furniture and equipment:
chairs, desks, telephone. A licence to use laboratory equipment (centrifuge, refrigerator,
freezer) has been requested. The actual instruments (sphygmomanometers, scales, etc.)
will be brought in by the field workers. The field teams should double-check the facilities
and laboratory equipment in good time by phone before going to the health centre in
question (appendixes 1 and 2).
4 STAFF
The public health staff at the Department of Public Health Science and General Practice
(KTTYL), University of Oulu, will plan and implement the study. Most important co-
operative partners are: several other departments of the University of Oulu, the
University of Lapland, Oulu Regional Institute of Occupational Health (OATTL),
National Public Health Institute, National Research and Development Centre for Welfare
and Health (STAKES), and Ministry of Social Affairs and Health. In addition, the Health
and Social Health unit of the Oulu Polytechnic has co-operated in the training of the field
workers. The labour administrations in Oulu and Rovaniemi have helped with
employment services.
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The field work will be carried out by four teams, each consisting of two public health
nurses (or corresponding professionals) and one laboratory analyst. The study teams in
Oulu also have a third public health nurse (appendix 3). Local health care institutes will
provide a student as occasional assistance. Administrative assistant Tuula Ylitalo at
KTTYL will keep record of appointments, and she should be contacted in case there is a
need to re-schedule an appointment in any municipality.
At KTTYL, the relevant persons in charge from the study’s point of view are: docent
Marjo-Riitta Järvelin (executive researcher of the project), researcher Lic.Med. Paavo
Zitting (field leader of the project), application designer Markku Koiranen (in charge of
ADP), secretary Tuula Ylitalo (in charge of appointments), and laboratory analyst Kaisa
Harjukelo (in charge of laboratory tests) (appendix 4).
5 SCHEDULE
The training of the field workers will take place at the end of March (3 days) and on 1-11
April 1997 at the Health and Social Health unit of the Oulu Polytechnic and at KTTYL.
The subjects of the preliminary study will be examined at the Oulu University Hospital
(OYS) on 14-18 April. Field work will start on 21 April 1997 in all four teams: Oulu,
Northern Ostrobothnia, Southern Ostrobothnia, and Lapland (appendix 2). In the first
stage, the study will continue until the end of June, and after the holiday season, from the
end of July until all study subjects have been examined. The estimated duration of field
work will be 5-6 months. The exact date of termination will be found out by the end of
June.
Appointments will be scheduled for 8.00 – 11.30 on Mondays to Fridays (appendix 5).
After the scheduled appointments there may be some postponed appointments, which will
take 30-60 minutes. The field workers will further spend 1-2 hours recording, calling
people, etc., which means that their working day will end at about 15.00. The study
schedules must always be checked on the working list sent in advance as there may be
some changes of appointments.
6 FIELD WORK
6.1 Mailing of invitations and changes in schedule
The cohort members are mailed a letter of invitation (appendix 8) to attend a health
check-up and a postal questionnaire with instructions to fill it in. The addresses are
obtained from the central census register.
The letter of invitation is mailed 2 - 4 weeks before the appointment. The letter explains
the purpose of the examination and gives the place, date and time of the appointment. A
notice for the subject’s employer will be enclosed.
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About 20 persons per team are scheduled for each day. About 70% are expected to
attend, which will mean 14-15 examinations daily. Appointments are scheduled at ten-
minute intervals during 8.00 – 11.30.
Invitations and questionnaires are mailed from KTTYL. The teams are provided for
appointment lists (= working lists), which indicate, by municipality and date, the names,
ID codes, social security codes and addresses of the subjects invited as well as the times
of appointment and the sub-samples the subjects are known to belong to (appendix 6).
The subjects can change the time of appointment by calling the KTTYL telephone
number given in the letter of invitation (08-5375659, secretary Tuula Ylitalo). As far as
possible, a new appointment is arranged for the same day as the original one. If this is not
possible, a new appointment is scheduled for another day. The teams call Tuula Ylitalo at
KTTYL for changes in their appointment lists the previous weekday afternoon.
The subjects who fail to turn up or to make a new appointment are re-invited by the field
workers over the telephone (appendix 10). The field workers should try to contact the
non-attendees on the same day and to make a new appointment immediately either for the
same day or for another suitable day. The new appointment should also be included in the
appointment list. KTTYL should be informed about the change in the same afternoon to
keep the person responsible for appointments aware of the new appointments.
The subjects who fail to turn up for the examination and have not been booked for a new
appointment by the local team over the phone are marked on the appointment list and
reported to KTTYL on the following afternoon. They are mailed a re-invitation to attend
the examination in a nearby larger locality (Oulu, Raahe, Rovaniemi, Kemi, Kajaani,
Kuusamo, Tornio) at the end of the examination programme regardless of the subject’s
place of residence.
If the field team is able to contact a subject who has failed to attend the examination and
is still unwilling or unable to attend, the reason for this should be discreetly elicited and
recorded on the working list. During the telephone call, the subject is asked if he/she
could fill in the postal questionnaire despite of his/her non-attendance. If he/she agrees, it
is marked on the working list. KTTYL is informed about the matter in the afternoon
during 13.00 – 15.00, so that they can dispatch the questionnaire, the consent form and a
return envelope.
6.2 Field work in practice
The staff at the reception/information desk of the health centres and the Oulu University
Hospital (OYS) are requested to help the study subjects find the right waiting room.
The general course of field work is described in appendix 9. Each subject is first seen by
the laboratory analyst (LA) for about 15 minutes. After filling in the questionnaires in the
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waiting room, the subject is seen by the first study nurse (SN1) and then by the second
study nurse (SN2). At the end, the subject fills in the “Pen computer questions” form,
after which SN2 discharges him/her. In Oulu the subject is discharged by SN3. The
average time the subject spends with each study nurse is about 15 minutes (30 – 45
minutes in total). About 15 minutes is spent with the laboratory analyst in addition to the
filling in the questionnaires (15 – 30 minutes). The subject should reserve more than an
hour for the visit.
At the beginning of the health check-up, the subject is asked to return the consent forms.
A list of stickers has been printed for each subject to identify the forms and laboratory
samples (appendix 7).
In addition to the notes made on the forms, blood pressure measurements are recorded
separately and forwarded to KTTYL weekly along with the other documents.
6.2.1 Samples and examinations
6.2.1.1 Health check-up sample
All members of the cohort (7200) living in the provinces of Oulu and Lapland and, later
on, a part of members living elsewhere in Finland.
1) Postal questionnaire: return, checking and filling in when needed
2) Health check-up:
- interviews
- additional questions
- blood pressure and heart rate
- skin prick test
- spirometry
- height and weight
- hip and waist circumferences
- physical performance capacity
- questionnaires to be filled in at home
3) Laboratory tests:
- blood samples
- nail sample
6.2.1.2 OATTL sub-sample (appendix 14)
- 200 first successive study subjects who arrive to the health check-up are chosen to the
specified study on working and functional capacity. They come from the following
municipalities: Oulu 100, Haukipudas 20, Kempele 20, Kiiminki 12, Ii 8, Muhos 8,
Liminka 8, Tyrnävä 8, Ylikiiminki 8 and Lumijoki 8
- Equal number of men and women
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- Equal number of employed and unemployed within each sex
- No people with handicaps are chosen
- Brief oral information about the study is given
- Exercise and food diaries for 7 days, instructions and portion pictures are given in an
envelope to be filled in at home and returned to OATTL
- Appointment is given for the examinations at OATTL
- Appointment is included in the invitation letter in the envelope (with instructions for the
subject) and it is marked in the separate appointment list, too
- ID codes of subjects who refuse the study and the reason for refusal are recorded on a
separate list which follows the appointment list
- Appointment lists are faxed to OATTL on Fridays, Leena Maljanen fax. 08-5376000
6.2.1.3 Psychiatric interview sub-sample (appendix 15)
- In the municipalities of Oulu, Oulunsalo, Liminka, Hailuoto, Ylikiiminki and Muhos
- About 500 subjects are chosen based on the so called SCL-25 question which is the
postal questionnaire question number 30 charting mental symptoms
- When checking the postal questionnaire SN1 also checks that question number 30 has
been answered completely. In case of need, for example visual impairment, the subject is
helped to fill in the questionnaire
- In case the sum of the answers is 39 points or more, an appointment for the interview
(SCID interview) is arranged and recorded on the separate list
- In addition to above mentioned, the first person whose total points are under 39 is
chosen to the interview. If he/she refuses, the next one is chosen etc.
- If the subject refuses the interview, his/her ID code and reason for refusal are recorded
on the back of the list
- It is desirable that at least some of the subjects could be interviewed on the same day; if
the same day is out of the question, a new appointment is scheduled for one of the next
few days
- The subject is given an invitation to an interview in a plastic folder/envelope (time of
the appointment included) and a questionnaire to be filled in beforehand (SCID II) which
is a part of the interview
- Finally, the subject is directed to the examination site or the ward number 73 that is
located in the middle clinics of the Oulu University Hospital (OYS)
6.2.1.4 Audiometry sub-sample
- About 1300 subjects recorded on the appointment list
- SN2 (SN3 in Oulu) interviews them and conducts the audiogram at the end of the field
study
- The audiogram in Oulu is conducted by the nurses of the Hearing Center
6.2.1.5 Osteoporosis sub-sample
- All the subjects in Oulu
- SN3 measures the bone density in the wrist
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- The instrument prints out a sheet which is enclosed with the examination form
- The subjects can be told that the bone researcher will analyse all the results later on and
gets in touch in case the result is so abnormal that additional examinations are required
6.2.1.6 Twin sub-sample
- About 300 twins, recorded on the appointment list
- They get a separate questionnaire with the postal questionnaire. It is checked and
returned with other forms to KTTYL
6.2.2 Division of tasks between field team members
LA:
- Verifies the subject’s identity
- Asks if the subject has filled in the postal questionnaire beforehand. If the subject has
not filled in the form at all or almost at all, he/she is asked to do this in the waiting room.
At this stage, the questionnaire is not reviewed in detail
- Asks the subject to fill in and sign the consent form that allows the data collected during
the health check-up to be used for scientific purposes
- Takes the subject’s sheet of stickers, cuts out the form stickers and fixes a sticker to the
right top corner of the consent form as well as the working and study forms
- Uses a paper clip to attach the other form stickers to the working and study forms
- Asks about the duration of fasting and the quality of the latest meal
- Draws a blood sample from the subject’s left arm
- Puts the identification stickers on the blood tubes and writes the time the blood sample
was taken on one tube
- Makes sure the samples are processed immediately:
- Serum and plasma tubes should be centrifuged within less than 90 min after
drawing the sample
- Ascorbic acid should be precipitated right after centrifugating (within less than
30 min after drawing the sample), and plasma and cells must be separated
immediately
- Serum tube of metal samples should be separated right after centrifugating (into
acid washed tube)
- Gives the study subject the ”Questions about work” form to be completed, or
alternatively, instructs him/her to fill in the ”Pen computer questions” form in the waiting
room
- In the afternoon:
- Delivers the partial blood count tests to the laboratory and collects the results
and attaches (staples/writes) them to the study form
- Makes sure the laboratory samples are processed appropriately
* Separates sera from centrifuged tubes into cryotubes
* Puts stickers on the cryotubes
* Packs the laboratory samples into the dispatch boxes
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- Fills in the dispatch note for each dispatch box and encloses a collated list of the
day’s study subjects with the test tubes
- Takes the first sticker of OYS and puts it on an empty A4 sheet. The stickers of
all study subjects examined the same day are put on the same sheet. The date of
sampling is corrected on the sticker if it differs from the original
- Puts the sticker made for the collated list, for example KTL-LÄH
- Makes sure the samples are taken to the post office/bus station
- Lays out the instruments ready for the next day
- Makes sure test tubes, other laboratory equipment and dispatch boxes are
available in the study facility
- Makes sure the results (also the reference values of manufacturer) of the partial
blood count control tests made in the health centre are dispatched from the
laboratory to KTTYL. Asks the health centre to send the copy of quality control
of each month afterwards
SN1:
- Checks the postal questionnaire and the “Questions about work” form in detail and asks
the subject to fill in the missing items and helps to fill in the form when needed
- Carries out the interviews and asks the questions concerning the skin prick test
- Measures blood pressure twice
- Measures heart rate for 30 seconds twice between the blood pressure measurements
- Performs spirometry
- Makes the prick skin test
- Makes sure that the subjects are included in the lists and makes appointments
- Contacts non-attendees by telephone
- Contacts KTTYL in the afternoon about changes in appointments and other matters
- Is in charge of the team work (team leader)
SN2:
- Measures waist and hip circumferences
- Measures height and weight
- Reads the outcome of the skin prick test
- Conducts the tests of the physical performance capacity in the following order:
1) grip strength
2) step test
3) back muscles
- Fills in and gives the immediate feedback form to the subject
- Instructs the subject to fill in the “Pen computer questions”, or alternatively, “Questions
about work” on paper
- Gives the subject the questionnaire about personality, a return envelope and an envelope
for a nail sample
- Makes sure the arrangements for the further studies of sub-samples are made:
- Gives the food and exercise diaries for 7 days to the subjects of the OATTL sub-
sample, gives an appointment and instructions for the examinations
- Gives an appointment and instructions to the subjects of the psychiatric
interview sub-sample
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- Interviews the subjects of the audiometry sub-sample and conducts the
audiogram (in OYS performed in the Hearing Center)
- Makes sure the subject has seen all team members and all tests have been made and all
documents appropriately filled in. Makes sure the subject has got all the forms to be filled
in at home
- In the afternoon:
- Records the postal questionnaire forms with the bar code pen, and when needed,
the pen computer questions with the pen computer
SN3: (in Oulu)
- Carries out the tasks that belong to SN2 after the “Pen computer questions” forms have
been filled in by the subjects
- Measures the bone density in the wrist
- Checks the forms in detail question by question
- In the afternoon, helps the sample consignee working in OYS
- Makes sure the questionnaires are dispatched to KTTYL
6.2.3 Description of the most important field tasks
6.2.3.1 Admission of the study subject, verification of identity and consent for using
the data
The subject is asked his/her name and date of birth. The subject’s name is marked on the
appointment list to show that he/she has attended. The subject is asked to fill in and sign
the separate consent form. The subject’s sticker sheets are separated from the other
sticker sheets. Identification stickers are fixed to the study form and the consent form.
The rest of the stickers are attached with a paper clip to the front page of the study form.
6.2.3.2 Filling in the “Postal questionnaire” form
The study subjects have received the study form 2-4 weeks before the examination by
mail. They have been asked to fill in the form at home. SN1 checks the form
preliminarily. In case the form hasn’t been filled in, the nurse asks the subject to step
aside and fill in the form, and then return to the first team member. SN1 checks the form
in detail, but in Oulu and Lapland it is done by SN3. This means that the form is checked
in detail question by question. Missing information is filled in, inadequate replies are
supplemented and erroneous responses are corrected. Special attention should be paid to
the questions with “yes-no” answers to make sure that even the “no” alternatives have
been marked.
6.2.3.3 Interviews
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In interview, the subjects are asked the questions that are meant to be asked.
6.2.3.4 Filling in the “Questions about work” and “Pen computer questions” forms
The subject is given the “Questions about work” form on paper. He/she fills in the form
up to the “Test results” section which is filled in by the field workers. The subjects fill in
questions also by using the pen computer (Pen computer questions, Working capacity
index or WCI and 15D). In the first place, the “Questions about work” form should be
filled in before going to SN1, and the “Pen computer questions” in the end, after seeing
SN2. Filling in the forms takes place in the waiting room. If the pen computer is occupied
by the previous subject, the same forms can be filled in on paper alternatively. In the
beginning and later on if needed, the subject is instructed how to use the pen computer.
Completeness of information is checked from the paper forms in the same way as from
the postal questionnaire form.
6.2.3.5 Measurement of heart rate
Heart rate is measured at the right radial artery (arteria radialis) for 30 seconds. The result
is recorded on the study form and the feedback form.
6.2.3.6 Measurement of blood pressure
In the measurement point of blood pressure:
- The subject arrives and sits down
- The cuff is placed on his/her right upper arm
- The number of the person carrying out the measurement is entered on the study form
- Necessary questions are asked (antihistamines, fats, others …)
- The first measurement of blood pressure is made
- The result is recorded on the study form
- Heart rate is measured
- The second measurement of blood pressure is made
- The result is recorded on the study form and the feedback form
A mercury sphygmomanometer is used to measure blood pressure. The measurement is
always carried out with the subject in a sitting position. The subject is asked to sit down
by a desk, the cuff of the sphygmomanometer is placed on his/her right upper arm. Cuff
size is 14 cm x 40 cm. The cuff is wrapped around the upper arm tightly without causing
excessive pressure. It should be possible to inset the index finger between the cuff and the
axillary aspect of the upper arm. Before the cuff is placed, the subject is asked to take off
tight garments, so that there is no other pressure on the arm and no parts of garment
remain under the cuff. The tubes of the cuff should be on the axillary side of the arm to
make the inflatable pad exert pressure on the central part of the brachial artery. The lower
edge of the cuff should be 2-3 cm above the antecubital fossa to leave enough space for
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the stethoscope. When the cuff has been placed and fastened and with the subject sitting
on the chair, he/she is asked the questions to be asked, and the postal questionnaire and
the “questions about work” form are checked in detail. The number of the person
performing the measurement is recorded on the study form.
Before the measurement, the nurse palpates the brachial artery to locate the point with
maximum pulsation. After that, the arm is placed on the desk with the palm upwards and
allowed to relax. While inflating the cuff, the nurse should keep her finger tips on the
radial artery at the wrist. The cuff is quickly inflated to a pressure of about 30 mmHg
above the point where the radial pulse faded. The stethoscope diaphragm is placed lightly
on the antecubital fossa at the point where the maximum pulse was previously palpated.
Too much compression by the stethoscope may cause excessive pressure on the artery
and result in noise.
The cuff is deflated slowly, so that the mercury column drops about 2-3 mmHg at each
heart beat. The pressure should be released evenly. Deflation should never be interrupted
and the cuff re-inflated, but the cuff should always be fully deflated. In case the
measurement fails for some reason, the cuff should be deflated and another measurement
performed immediately.
Systolic blood pressure is the pressure where the first recognizable pulse sound is heard
(Korotkoff’s stage I). Diastolic blood pressure is the pressure where pulse sounds are no
longer heard (Korotkoff’s stage V). If the subject’s diastolic blood pressure can be heard
to point zero, the measurement should be repeated and Korotkoff’s stage IV, i.e. the stage
at which the sounds get weaker, should be recorded as the blood pressure value.
It is important to keep the arm at the level of the heart (at roughly the fourth intercostals
space and at the angle of 0 -40° relative to the body) during the measurement. The
systolic and diastolic blood pressure values are recorded to the nearest 2 mm. The
sphygmomanometer scale should be kept perpendicular to the eye level of the person
conducting the measurement.
The blood pressure values are recorded immediately on the study form. After the first
measurement, the cuff is deflated completely, but left on the arm. When the first blood
pressure values have been recorded, heart rate is measured. After that, the second blood
pressure measurement is made in the same way as the first.
In the afternoon, the blood pressure values are recorded on a follow-up form, which is
mailed to KTTYL weekly along with the other documents.
6.2.3.7 Skin prick test (appendix 12)
Before the skin prick allergy test, the subject is asked the questions given on the study
form. If there are no contraindications, SN1 makes the skin pricks on the skin of the
lower arm. The test result is read by SN2.
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6.2.3.8 Spirometry
At first, it is checked that the subject does not wear any tight garments and that he/she is
sitting upright. After a nose clip has been placed, the subject is asked to inhale deeply.
He/she then places the mouthpiece between his/her teeth and lips and closes his/her lips
tightly around it. After that he/she is instructed to exhale as deeply and forcefully as
possible. Three parallel results (curves) should be obtained: the difference between the
two maximal FEV 1 and FVC values should not exceed 4 %. Taking out the false teeth is
considered case by case. Parameters to be recorded: FVC = forced vital capacity, FEV 1
= forced expiratory volume after 1 second. The results are recorded on the study form and
on the feedback form with examples of reference values for a man and a woman of
average height.
6.2.3.9 Measurement of waist and hip circumferences
Before the measurement, the subject is asked to take off any tight garments and to wear
only his/her underwear. The subject is instructed to stand with his/her legs slightly apart
and with weight on both legs. The feet should be about 10-15 cm apart. The person
making the measurement should sit down, to have maximum visibility of the area to be
measured. Waist circumference is measured halfway between the iliac crest and the
lowest rib. Hip circumference is measured at the widest point of the hip, with the tape
measure on the pubic bone. The subject should breathe normally and exhale lightly
during the measurement. It is important to keep the tape measure horizontal. This can be
checked by asking the subject to turn 90°. The tape measure reading is recorded on the
study form rounded to the nearest half centimeter. Circumference measurements are not
taken from pregnant women.
The tape measures used for the examination should be checked with a metal measuring
rod weekly. If the tape measure is stretched, it should be replaced. In any case, tape
measures are replaced at 2-month intervals.
6.2.3.10 Measurement of height and body weight
Height and body weight are measured after the measurements of waist and hip
circumferences with the subject in underwear. The study team brings the height measure
to the study site. The height measure is placed against a wall and the accuracy of
measurement is checked every morning. The subject stands on the platform with his/her
feet together and his/her back straight against the wall, looking directly ahead, with the
eyebrows and the openings of the external auditory canals horizontally aligned. The
result is recorded on the study form to 0.1 cm accuracy.
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Body weight is measured with scales to the nearest 0.1 kg with the subject in underwear,
and the result is recorded on the study form. The scales brought by the field team should
be used.
If the subject is unable to move, self-reported height/weight are requested and recorded
on the form. It should also be indicated clearly that no measurements were made. If a
subject able to move refuses to have his/her height/weight measured, the item is left
empty. Pregnant subjects are inquired about their weight before pregnancy, and weight is
not measured.
6.2.3.11 Measurement of physical performance capacity (appendix 13)
The strength of clenching the fist is measured in the test of grip strength. The study
subject stands with the measuring handle in his/her dominant hand close to his/her body.
The handle is adjusted so that the second phalanx of the index finger is perpendicular to
the handle. When ordered, the subject clenches the handle as tightly as possible for 4
seconds. The body must be kept straight and the subject must not clench against his/her
body. The measurement is repeated three times at least at fifteen-second intervals and all
the results are recorded on the study form, the best result also on the feedback form. The
instrument indicates the maximal grip strength.
Step test is performed by stepping onto a 33-cm-high bench for women and a 40-cm-
high bench for men for four minutes. Stepping happens 22½ times a minute at the pace of
metronome. Heart rate is measured with the pulse counter and the measuring handle after
the performance, and the result is recorded on the study form and the feedback form.
The back’s static endurance test is performed in prone position over two step test
benches. In case the subject’s weight is above normal, two seven-cm-high platforms can
be added over the benches. At first, a gymnastic mat is placed to pad the platforms. The
upper body lies outside the benches beyond the pelvis bone crista iliaca anterior superior.
SN2 places a weight (= plumb) so that it touches the back while the subject holds his/her
body horizontal supporting it by hands. SN2 holds his/her feet and the subject holds
his/her body, hands close to his/her sides, in the horizontal level touching the weight
behind his/her back as long as he/she can, for four minutes at the maximum. If the back
fails to touch the weight, the subject is asked to correct his/her position immediately. If
he/she is unable to do this, the test is declared completed. The result is recorded on the
study form and the feedback form.
6.2.3.12 “Opinions” form and collecting nail samples
All the study subjects are given the “Opinions” form to be filled in at home and a small
envelope for the nail sample with printed instructions how to take it. They are also given
a return envelope. The subjects must be pointed out that filling in the questionnaire
thoroughly and taking the nail sample are essential for a successful study. Returning them
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happens by mail to KTTYL. In Oulu, the subjects who are chosen to the psychiatric
interview, get the “Opinions” form, an envelope for the nail sample and a return envelope
from the psychiatric interviewer. The field workers deliver them and ID stickers to
him/her with an appointment form.
6.2.3.13 Audiometry
SN2 (in Oulu SN3) carries out the interview for audiometry. After that the subject is
taken to the measurement of hearing. In OYS, it is performed by the nurses in the
facilities of the ear department in the Hearing Center, elsewhere, by SN2 (in Lapland by
SN3) with the equipment of the health centre. The audiogram equipment has been asked
to be calibrated beforehand in the Hearing Center of OYS.
In the examination, auditory threshold for air-borne sounds of both ears is determined in
the frequencies of 0.25, 0.5, 1, 2, 3, 4, 6 and 8 kHz. The result is recorded in numbers on
the hearing interview form and on the separate feedback form. Each measuring result
with the threshold over 20 dB (or ≥ 25 dB) is interpreted as abnormal. In case the average
(PTA, pure tone average) of speech frequencies (0.5, 1, 2, 4 kHz) exceeds 30dB in the
better ear, the subject can be told then and there to have impaired hearing.
6.2.3.14 Food and exercise diaries
The subjects who belong to the OATTL sub-sample get exercise and food diaries for 7
days. He/she returns them when coming to further studies at OATTL. The subjects must
be pointed out that filling in the diaries thoroughly is essential for a successful study. It
would be worthwhile for the subject to familiarize him/herself carefully with the
instructions and examples before filling in the food diaries. There is no time to read the
instructions during the examination. The nurse is supposed to tell briefly about the
matter, show the equipment, and encourage and motivate the subject to do the work at
home. SN2 gives the diaries with instructions.
6.2.3.15 Venous blood sample
The laboratory analyst (LA) asks the subject about the duration of fast before the
examination, and records the time rounded to the nearest full hour on the front page of
the study form. After that, she inquires about the quality of the latest meal (if the fast < 8
hours) and records this information on the study form.
LA places the test tubes on a rack. The venous blood samples are drawn from the
antecubital vein of a sitting subject, using the closed vacuum method. The antecubital
fossa is exposed and a tourniquet is applied to the left upper arm. The skin is cleaned with
Neo Amisept. As soon as the needle has been inserted into the vein the tourniquet is
released. A 20G needle is used to draw the blood sample. After drawing the samples, LA
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fixes identification stickers on the test tubes and writes the time of sampling with a felt
pen on the first serum tube.
The blood samples are taken in the following order:
1) Serum gel tube (1 x 10 ml)
2) EDTA tube (1 x 3 ml)
3) The rest of the serum gel tubes (women 2 / men 3 x 10 ml)
4) Trace element serum tube (1 x 7 ml)
5) Lithium-heparinum tube (1 x 5 ml)
6) Trace element – heparinum tube (1 x 7 ml)
7) EDTA tubes (1 x 3 ml and 1 x 10 ml)
The serum gel tubes are turned upside down a couple of times after drawing the sample.
The tubes containing anticoagulants are mixed by turning seven times upside down. The
trace element serum tube is not mixed. The tubes are placed on a rack for further
processing. The samples are processed as described later on.
6.2.3.16 Processing of blood samples
The serum tubes are kept at room temperature for 30 minutes. All the samples that need
to be centrifuged are centrifuged at 1900 G value for 10 minutes at +20°C (Formula for
calculating speed of rotation at the end). The sample tubes are centrifuged within less
than 90 min after drawing the sample unless otherwise advised in each examination.
Serum and plasma samples must be centrifuged.
1) Serum gel tube
In the examination, 3 x 10 ml serum gel tubes are taken from women and 4 x 10 ml from
men, and they are let stand for 30 minutes after drawing the sample. After that the
samples are centrifuged and the serum is separated into a transportation/freezer tube in
the afternoon.
Separated serum is put into nine transportation/freezer tubes after centrifugation
according to the following instructions. The study and subject specific stickers are
attached to the tubes, and they are packed in separate examination specific bags.
Separation of serum gel tubes happens in the following way:
• For assay of insulin 1.0 ml into a tube of OYS. The sample is packed in a dispatch
box to be delivered to OYS and kept in +4°C until the delivery
• For assays of cholesterol and triglyserides, HDL and LDL cholesterols 2 x 1.0 ml
into tubes of OYS
• For analysis of P1NP 1.0 ml serum into a cryotube
• For assays of serum antibodies and cytokine 1.0 ml serum into a cryotube packed
in a dispatch box to be delivered to OYS, KTL Oulu
• For analysis of cotinine 1.0 ml serum into a cryo tubepacked in a dispatch box to
be delivered to OYS, KTL Oulu
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• For S-HORM 2 x 1.0 ml into cryotubes
• 1.5 ml of serum into a cryotube for a long-term deep freezing
2) Trace element serum tube
The trace element serum tube is let stand for 30 minutes. The tube must be kept closed all
the time to prevent the contamination. 2-3 ml of serum is poured into a colourless acid
washed tube after centrifugation
3) EDTA tubes
A) 2 x 3 ml EDTA tubes are mixed by turning them seven times upside down to make the
anticoagulant blend and dissolve evenly in the sample
• 50 μl of blood of the first 3 ml EDTA sample tube is precipitated with 0.5 ml of
perchloric acid for assays of fasting glucose level. The precipitation tube is mixed
with care.
• The rest of the sample tube is dispatched to the laboratory of hematology in
OYS/to the laboratory of the health center in the same day. Eryt, leuk, Hb, Hct
and red blood cell index will be examined.
• 1.5 ml of whole blood is decanted from the other 3 ml sample tube into a cryotube
after the careful mixing.
B) The 1 x 10 ml EDTA tube for assay of B-DNA is mixed and dispatched as such.
4) Trace element – heparinum tube
Natrium heparinum – trace element tube is mixed for assay of metals by turning it slowly
seven times upside down.
5) Lithium – heparinum tube
The 1 x 5 ml lithium – heparinum tube is turned slowly seven times upside down. The
tube is centrifuged immediately after it has cooled down to the room temperature and the
plasma is separated in the following way:
• 1.5 ml of plasma into a cryotube.
100 μl of plasma must be separated for assay of ascorbic acid (within less than 30 min
after drawing the sample) and 900 μl must be stabilized into fridge cold metaphosphoric
acid. The tip of a pipette is rinsed in the plasma in the plasma tube before pipetting.
• 1.5 ml of cells into a cryotube.
FORMULA FOR CALCULATING SPEED OF ROTATION AND EXAMPLE
Formula for calculating speed of rotation (rpm): G = 1,12*10-5r(cm)*rpm2
where acceleration G = 1900
if radius r = 16,5 cm, then 1900 = 1,12*10-5*16,5*rpm2
rpm2 = 1900: (1,12*10-5*16,5)
rpm = 1900: (1,12*10-5*16,5)
rpm = 3206
The serum tubes are centrifuged in a 16,5 cm rotor centrifuge at 3200 rotations per
minute for 10 minutes. The rotor radius is measured from the centre of the rotor hub to
the bottom of the tube.
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7 PROCESSING OF DOCUMENTS AND SAMPLES, MAINTAINING
CONTACTS AND INFORMATION SERVICE
7.1 Study forms
The information given in the postal questionnaire form is recorded in the field. The
subjects fill in a part of questionnaires (Pen computer questions, TK1, 15D) with the pen
computer so they don’t need to be recorded separately. Only if the subject fills in these
forms on paper, the information in them is recorded also in the field. The teams must
have a pen computer as well as a PC for recording. The afternoons of the examination
days are reserved for this task. The information of each day is recorded on a separate disk
and the copies of the information recorded during the week are made on a backup disk
weekly.
All forms collected during the week (Monday – Friday) are compiled and dispatched in a
delivery box to the Department of Public Health Science and General Practice on Friday
or on the following Monday at the latest. The disks that consist of the information
recorded from the questionnaires during the week are enclosed. The ordinal number of
the delivery, the number of forms, the content of the disk and the date of delivery are
recorded on a separate form. The KTTYL staff keep record of the deliveries received.
7.2 Dispatching of laboratory samples
The samples are packed examination by examination in Minigrip plastic bags in the field
work sites. The sample bags are packed in a sample dispatch box that is carefully taped
closed. The collated lists with the dispatch stickers of the samples in the numerical ID
order are enclosed with the sample dispatch box. Collated lists of small stickers are made
for 1) the freezing at the Oulu University Hospital and for 3) the National Public Health
Institution in Oulu and with bigger stickers for 3) the routines at the Oulu University
Hospital only of the subjects whose date of sampling differs from the planned one. The
date of sampling is corrected with a pen on the stickers. The date of delivery and the
place of samples and examination site are marked in the collated lists.
The laboratory samples are dispatched by mail or bus or with a carrier. The laboratory
analyst makes sure that the samples are delivered daily. The samples are mailed to the
Oulu University Hospital (OYS) in Oulu where the samples are delivered further to the
National Public Health Institution in Oulu. The consignee of samples records the date of
arrival on dispatch notes and files the notes.
The partial blood count test: The results of samples and controls examined by the
laboratory are gathered daily and sent to KTTYL every week. The laboratory is asked to
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send each month’s quality control result of hemoglobin to KTTYL afterwards so that the
result level can be followed.
Hemoglobin, hematocrit, leukocytes, red blood cells, red blood cell indexes, triglycerides,
total cholesterol, HDL and LDL cholesterols, fasting glucose as well as fasting insulin are
analyzed immediately or within 3-4 weeks. The samples to be analyzed immediately are
analyzed in the laboratories of OYS except the partial blood count test that is analyzed in
the laboratory of the field work site outside Oulu. The rest of samples are stored in OYS’
own and the project’s freezers placed in OYS as well as in the deep-freezing spaces of the
National Public Health Institution in Oulu.
The Research Institute of Public Health at the University of Kuopio, MTT Agrifood
Research Finland in Jokioinen, the National Public Health Institute in Oulu, the Oulu
University Hospital, the Departments of Anatomy and Physiology at the University of
Oulu and the National Public Health Institute in Helsinki are planned to be examination
locations of samples in future.
7.3 Maintaining contacts
The SN1 of each field team calls Tuula Ylitalo at KTTYL (tel. 981-5375659) at 13.00 –
15.00 daily to report the names of subjects who attended / did not attend the examinations
that day. On that same occasion, the field team is informed of possible changes in
appointments made at KTTYL. Information is recorded on the working lists at KTTYL
and in the field unit respectively as previously arranged. It is also possible to discuss any
problems encountered in field work, and the phone call can be connected to Paavo Zitting
or Marjo-Riitta Järvelin.
To contact the non-attendees, SN1 tries to call each of them during the same day to invite
them to attend (appendix 10).
The results of blood pressure measurements are recorded separately in addition to being
recorded on the study forms. The collated lists are mailed to KTTYL weekly.
7.4 Information to the study subjects
The study subjects are informed of their blood pressure, heart rate and physical functional
capacity on a feedback form, which also contains briefly the reference values and a
description of the recommended measures.
If diastolic blood pressure is 95 mmHg or higher in both measurements the subject is
considered to have elevated blood pressure. The subject is asked if his/her blood pressure
is being monitored or if he/she gets medical treatment. If the subject is being monitored
or treated, he/she is instructed to continue it as recommended. Otherwise, the subject is
instructed to consult a public health nurse in the health centre for a re-measurement in the
22
near future. If diastolic blood pressure is 120 mmHg or over, the subject is instructed to
consult a doctor soon. If there are concurrent symptoms, such as nausea, vertigo,
headache, etc., the subject is instructed to consult a doctor immediately.
The subjects are informed by mail of their allergy skin test and spirometry test results as
well as of the partial blood count test, cholesterol and fasting glucose values of the
laboratory test at the end of the project (fall/winter 1997). If the subjects ask about the
other laboratory tests, they should be told that these analyses will serve scientific basic
research and it is not known yet what significance they may have for the subject’s health.
No reference values can therefore be given.
Any other questions possibly asked by the subjects should be answered kindly but, if
possible, briefly. The team members should discuss any frequently asked question and
inform KTTYL about them.
Concerning the application of the results, the subjects can be told that the results will be
used for planning similar projects in the future, and that the scientific results of the whole
project will be published primarily in Finnish and international medical journals. The first
results will probably be published about a year after the completion of the project. The
research data will be analyzed and published anonymously. Furthermore, the health care
staff are obliged to keep all information absolutely confidential at all stages of the study.
7.5 Information to the press
The field teams are given a press release for informing mainly the local papers. Any
requests for interviews and photographs by papers should be accepted. For photographs,
however, the subject should also be asked for consent. For more detailed interviews, the
reporters should be referred to KTTYL.