The SA Journal Diabetes & Vascular Disease Vol 16 No 1 (July 2019)

SA JOURNAL OF DIABETES & VASCULAR DISEASE

RESEARCH ARTICLE

VOLUME 16 NUMBER 1 • JULY 2019

hypertension in PHC facilities. The aim of this study was to determine

the prevalence and determinants of CV risk factors among patients

with hypertension in a large, peri-urban PHC facility in Gauteng

province, South Africa.

Methods

This cross-sectional study was conducted in a large community

health centre (CHC) south of Johannesburg. At the time of the

study, from March to May 2012, the CHC provided ambulatory

curative, preventative and rehabilitation services, and served as a

referral centre for five smaller clinics. In the out-patient department

(OPD), there were three doctors, three PHC nurse clinicians and five

staff nurses.

In this facility, patients with hypertension are booked by

appointment for their monthly follow-up visits. A day before the

appointment, an administrative clerk retrieves patients’ medical

records from the archives for all patients booked. On the day of

the clinic visit, patients collect their files and proceed to sit in the

waiting hall, from where a nurse invites a group of 10 patients for

measurement of vital signs at the nurses’ station. Thereafter, the

patients are directed to a doctor or PHC nurse clinician, depending

on the complexity of the presenting problem.

In 2011, an estimated 1 974 patients with hypertension attended

this CHC. Assuming an annual increase of 10%, the estimated

patients with hypertension for the year 2012 was rounded off

to be 2 100. To determine the sample size, the researchers used

the Raosoft sample size calculator.

The required sample size

was calculated to be 328, based on a 5% margin of error, 95%

confidence level and a response distribution of 50%.

Patients were recruited into the study by the first author and

two staff nurses who were trained as research assistants. During

the sampling, a research assistant approached patients as they

presented for measurement of vital signs at the nurses’ station.

Every third patient with hypertension was sampled for recruitment

until the sample size was attained. If the third patient refused, the

next willing patient (fourth or fifth) who met the inclusion criteria

was approached and recruited.

To be selected, a patient had to consent to participate in the

study, be 18 years or older and have attended the CHC for at least

two months of hypertension treatment. Patients who participated

in the pilot study, emergencies, those with mental impairment and

those who presented after hours were excluded. Patients willing

to participate in the study were taken to an adjacent room where

the researcher and the second research assistant obtained informed

written consent.

ThefollowingCVriskfactorswereconsideredinthisstudy,informed

by relevance to PHC and financial costs: advancing age, gender,

obesity, left ventricular hypertrophy (LVH) on electrocardiograph

(ECG), tobacco and alcohol use, diabetes, physical inactivity, hyper-

cholesterolaemia, family history of hypercholesterolaemia and past

family history of fatal CV events.

After obtaining informed consent, the first author and second

research assistant (when interpretation was necessary) administered

the questionnaire, performed anthropometric and clinical

measurements, and performed ECGs in an adjacent room.

A structured researcher-administered questionnaire was

developed

de novo

in English, based on the literature. Each

questionnaire had a serial number identical to the corresponding

participant’s file number, in case of need for retrieval. Personal

identifying information was not collected. The questionnaire

collected information on:

• Sociodemography: age, gender, marital status, educational

attainment, employment status and ethnic group, tobacco use

(cigarette smoking, exposure to second-hand smoke and snuff

use) and alcohol consumption. Current smoking was defined

as self-reported active smoking within the last year before

examination.

Current alcohol use was defined as a patient

who regularly consumed alcohol (regardless of the type) in the

past 12 months.

• Clinical co-morbidity: self-reports of diabetes mellitus, family

history of hypercholesterolaemia and family history of fatal CV

events (defined as death of a close family member due to heart

attack or stroke before the age of 55 years in men or 65 years

in women).

• Engagement in physical activity: level of involvement and

duration of time spent on physical activity, whether at the

workplace, during leisure time or as household chores.

Engagement in physical activity was defined as reporting

moderate-intensity activities in a usual week for ≥ 30 minutes

per day, ≥ five days per week; or vigorous-intensity activities in

a usual week, ≥ 20 minutes per day, ≥ three days per week or

both.

The following examples of physical activities were used

to categorise participants. Moderate-intensity physical activity:

brisk walking, dancing, gardening, housework, domestic

chores, walking domestic animals, active involvement in games

and sport with children. Vigorous-intensity physical activity:

running, walking up hill, fast cycling, aerobics, competitive sport

and games such as soccer, hockey basketball, fast swimming

and heavy shovelling or digging.

Anthropometric measurements included abdominal circumference,

weight, height and body mass index (BMI). These were done using

equipment and procedures as recommended in the South African

hypertension guideline of 2011.

Each instrument was calibrated

before use and research assistants were trained to minimise inter-

rater differences. Measurements were done using:

• Weight and height: Seca

scale, manufactured by Seca

in Germany (model: 767-1321004, serial number:

1767002071575). Heights and weights were measured in

metres and kilograms to two decimal points. The research

assistant used the technique recommended by de Onis

et al

for weight and height measurements. Thereafter, the researcher

computed the BMI in kg/m

. Obesity was considered if BMI was

> 30 kg/m

• Waist circumference: flexible, non-elastic metric tape. The

research assistant used a flexible non-elastic tape measure

154 cm long and 15 mm wide, with 1-cm graduation intervals

for the waist circumference measurement. The measurement

was recorded at the end of a normal expiration at the midpoint

between the lower margin of the last palpable rib and the top

of the iliac crest on the mid-axillary line, with the tape parallel

to the floor at the level at which the measurement was done.

Each measurement was repeated twice and if the measurements

came within 1 cm of one another, the average was calculated.

If there was > 1 cm difference, the two measurements were

repeated. Central obesity was present if waist circumference

was ≥ 102 cm in men and ≥ 88 cm in women.

In the Asian

population, central obesity was considered in men if the

abdominal circumference was ≥ 90 cm and in women if the

waist circumference was ≥ 80 cm.