24-hour urine samples

Based on EHES Manual, Part B. Fieldwork procedures, 2nd edition, 2016 Available at: http://urn.fi/URN:ISBN:978-952-302-701-5 These slides can be used freely, translated and adapted to national use (e.g. concerning the equipment). However, it is important to keep in mind that no changes should be made to the measurement techniques, which need to be standardized.

Exclusion criteria 24-hour urine sample is not collected from participants with any condition that would make urine collection difficult with menstruation who refuse Reasons for exclusion are recorded.

Pregnant participants Results may need to be analyzed separately from those of other participants. Pregnancy should be recorded.

24-hour urine sample collection Motivation of the participant Explain to the participant that 24-hour collection is needed due to large diurnal variation. The participant collects the sample at home. The sample needs to be brought back to the examination site or picked up from the participant’s home. The collection starts in the morning and ends the following morning.

Equipment for collection Plastic beaker with lid for voiding, 1000 ml Plastic collection container with lid, 3000 ml

Equipment for processing and storage Pipet Stirring rod, plastic Freezer Plastic storage tubes, e.g. 3 ml storage tubes Cryo vials must be used if stored at -70°C or colder Storage box for plastic tubes / cryo vials

Instructions to the participants (1) Give the participant A 1000 ml plastic beaker for voiding A labelled 3000 ml plastic collection container with lid written instructions on collection of 24-hour urine sample sample collection recording form (also called laboratory form) Encourage the participant to follow a normal day (eating and drinking) during the collection, but to avoid excessive physical activity and alcohol use.

Instructions to the participants (2) Instruct the participant to start the collection in the morning by discarding the first void. The date and time are recorded. After this all urine is collected by using the beaker. From the beaker the urine is poured into the container. The last void is collected when 24 (±2) hours have elapsed since the beginning of the collection. End of collection (date and time) are recorded.

Instructions to the participants (3) Storing of the sample: During and after the collection, the container is stored in a cool place, preferably refrigerator (+4ᵒC), and sheltered from direct sunlight. The urine must not be frozen (under 0°C) before processed by survey personnel.

Instructions to the participants (4) Explain the delivery of the sample Either deliver the sample to the examination site or laboratory, or agree on a schedule of picking the sample up from the participant’s home (according to the study protocol). The sample should be delivered on the same day when the collection ends.

Sample delivery Check the sample collection recording form with the participant. Record the time and date, when the sample was delivered, in the sample collection recording form.

Processing of the sample Mix the sample well and measure or read the volume. Record the measured volume in the sample collection recording form. Transfer aliquots of 2 ml into storage tubes. Label the tubes and store at -20 ᵒC or -70 ᵒC. Preferably several aliquots are made for storage and future use. The remaining urine is disposed of.

Incomplete samples Check the completeness of the sample. The 24-hour urine sample is considered incomplete, if the volume of the sample is ≤500 ml, the collection time is <22 or >26 hours, or “more than few drops” of urine were missed during the collection. Reasons for judging a sample as incomplete should be recorded.

Acknowledgements Slides prepared by: Laura Paalanen Photographs: Laura Paalanen Experiences and feedback from the EHES network have been utilized in the preparation of these slides Funding: Preparation of the slides is part of the activities of the EHES Coordinating Centre which has received funding from the EC/DG SANTÉ in 2009-2012 through SANCO/2008/C2/02-SI2.538318 EHES and Grand Agreement number 2009-23-01, and in 2015-2017 through Grand Agreement number 664691/BRIDGE Health

Disclaimer The views expressed here are those of the authors and they do not represent the Commission’s official position.