A structured questionnaire adapted from the WHO STEPwise approach to non-communicable diseases (NCDs) risk factors survey (STEPS instrument)40 was used. The questionnaire was translated into the local language (Kiswahili) and then independently back-translated to English for validation. We obtained information about socio-demographic characteristics and potential risk factors for high BP. We also collected information about parent/guardian’s vital status, occupation and ownership of common household items which were used to generate categories of participant’s wealth index. We collected data using handheld electronic devices (TECNO Android Tablets) programmed to check for accuracy and consistency of entered data.

After the interviews, we conducted physical examination to collect anthropometric measurements. Height was measured in an upright standing posture on bare foot and without head ornament, using a portable stadiometer (SECA 213, SECA GmbH & co. KG., Hamburg, Germany) at a precision of 0.1 cm. Waist and hip circumference were measured over a single layer of clothing using a tape measure (SECA 201, SECA GmbH & co. KG, Hamburg, Germany) at a precision of 0.1 cm. Weight was measured with a participant in an upright standing posture, in light clothing and on bare foot, using a digital weight scale (SECA 876 flat scale, Seca GmbH &co. KG., Hamburg Germany) at a precision of 0.1 kg. The weight and height measurements were used to calculate the body mass index (BMI) which was categorized into underweight, normal weight, overweight or obesity using the WHO’s BMI for age Z-scores41.

We obtained AOBP measurements using a validated monitor (OMRON Model BP791IT—HEM-7222-ITZ, Omron Health care Inc., Lake Forest, Illinois, USA) while participants were seated in an upright position with an appropriate cuff size as determined from the participant’s right mid-upper arm circumference (MUAC). The BP measurement procedure was fully explained and done after resting for at least 5 min in a booth, the participant started the BP machine and three consecutive BP measurements and counts for heart beats per minute were automatically obtained at an interval of 1 min and precision of 0.1 mmHg. The first AOBP measurements obtained on ‘Day 1’ was used to screen for high BP (step 1) using the screening algorithm of the 2017 American Academy of Pediatrics (AAP) guideline18. Participants aged ≥ 13 years and whose AOBP measurement were ≥ 120/80 mmHg, or those aged < 13 years and whose AOBP measurement was ≥ 90th percentile for their age, height and sex screened positive for high BP. Additional two AOBP measurements were obtained on the same day 1 and their average were compared to reference table for age, sex and height (step 2). If average AOBP measurements were high (≥ 90th percentile for age, sex and height) on day 1, repeat AOBP measurements were obtained after about one month (‘Day 2′) using same procedure (step 3). The average of last two AOBP measurements obtained on Day 2 was used to obtain final BP percentiles using BP reference tables which takes into account participant’s age, sex and height [also available in a Statistical Analysis System (SAS) code] in the guideline18. Participants with final systolic and/or diastolic AOBP measurement ≥ 90th percentiles for their age, sex and height were regarded as having sustained high BP and were eligible for 24-h ABPM (step 4).

After physical examination and AOBP measurements, we collected 5 mL of venous whole blood for malaria, hemoglobin electrophoresis, and serum creatinine tests. While in the field, we used two drops of blood to test for malaria using rapid diagnostic test (ACCESS BIO, 65 Clyde Road, New Jersey, USA), and five drops of blood for preparing dried blood spot (Whatman 903 filter paper) samples. The remaining blood sample was transported to the central laboratory at the National Institute for Medical Research (NIMR—Mwanza) for further processing and testing. We also collected about 40 mL of urine sample for urine tests including 10 mL which was used for urine strip analysis (ACON laboratories Inc, San Diego, California—USA) at the field. We communicated abnormal results to the respective participants in presence of their parents/guardians. Additionally, participants with sickle cell trait or disease were counseled on what the results meant, what to expect and what they were supposed to do to modify the course of their disease as well as on the importance of screening for the disease before marriage.

Note: The content above has been extracted from a research article, so it may not display correctly.

Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.

We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.