Blood pressure self-measurements (section: physical state) were performed by Lifelines participants aged 18 years and older during:

• 4A Visit 1

The Hingmed DBP-01P automated blood-pressure monitor was used for self-measurements.

Blood pressure was measured in the right arm, unless the participant indicated to have one of the following contra-indications:

• Lymph node surgery on the right breast or armpit
• Complaints of fluid accumulation in the right arm
• A dialysis shunt in the right arm

If the contra-indication did not apply to the left arm, blood pressure was measured in the left arm. If it did apply to the left arm as well, blood pressure could not be measured.

• Blood pressure was measured during visit 1, after anthropometry self-measurement and before the measurements performed by a research nurse in the examination room.
• When registering at the reception desk, participants received a barcode that could be used to identify themselves at the self-measurement boot.
• Instructions were given via software on a laptop. Participants were instructed to remove clothing with long sleeves and to take a seat on the chair. They were asked to adjust the height of the table using an electronic control panel, so that the arm could be placed in the blood pressure device in a relaxed position. A bell was present in the boot to request assistance from an employee.
• The Hingmed DBP-01P measuring device was connected to the laptop on which instructions were given, and recordings were processed automatically.
• A maximum of 5 attempts could be used to collect 3 consecutive measurements.

For assessment 4A, the average systolic and diastolic blood pressures were calculated using the second and third successful measurement.

A validation study was performed to compare the results of the blood pressure self-measurements, with the results from the measurements performed by a research nurse. More information will follow.