Feasibility and acceptability of a contextualised physical activity and diet intervention for hypertension control in a rural adult population of South Africa

Introduction:

Over half the population of adults from rural South Africa are hypertensive. Most strokes and ischaemic heart diseases in rural and remote South Africa are because of hypertension, which is a modifiable risk factor. Apart from pharmaceutical treatment, lifestyle changes such as increasing physical activity and reducing dietary salt have been strongly advocated for the control of hypertension. Despite the known benefits of physical activity and diet modifications for hypertension control, adults in rural South African settings still have high levels of uncontrolled hypertension. There is a lack of culturally sensitive, community‐based, lifestyle interventions to control hypertension among rural South African adult populations. We designed, implemented, and evaluated a contextual intervention which recommends adjusting daily routine physical activity and dietary behaviour of adults with hypertension - HYPHEN (HYpertension control using PHysical activity and diEt in a rural coNtext). This study aims to evaluate the feasibility and acceptability of HYPHEN in a rural South African community setting.

STUDY ONE

Methodology: The first study involved establishing a profile of the frequency, intensity, duration, and domain (work or non-work) of self-reported physical activities of rural South African adults living with hypertension. Four hundred and twenty-nine adults diagnosed/self-report with hypertension aged 40 years and above completed the International Physical Activity Questionnaire Long-Form (IPAQ-LF) via telephone interview.

Results: Fifty eight percent of participants were women of which 44% were in paid/unpaid work, while 64% of men were in paid/unpaid work. Men reported greater (duration and frequency) vigorous physical activity at work compared to women. Walking frequency as mode of transport was higher for working men and women compared with those not in work. Women reported high frequency of moderate-intensity physical activity inside the house and outside the house compared to men. Non-working men and women spent more time sitting during the week compared to their working counterparts.

Conclusion: Sex, work status, and gender roles are related to physical activity among hypertensive adults living in rural South Africa. Further exploration of socioeconomic and cultural factors influencing physical activity in rural African populations is required so that appropriate contextual interventions can be developed and evaluated.

STUDY TWO

Methodology: The second study was a qualitative study to explore the social and cultural beliefs, perceptions and practices regarding physical activity and diet as a hypertension control intervention for adults living in a rural sub-district in South Africa. Nine focus group discussions were conducted with hypertensive adults using a semi-structured interview guide.

Results: Participants had a lack of knowledge about blood pressure values. Perceived causes of hypertension were related to psychosocial factors such as family and emotional-related issues. Physical activity practices were influenced by family and community members’ attitudes and gender roles. Factors which influenced dietary practices mainly involved affordability and availability of food. To control their hypertension, participants recommend eating certain foods, emotional control, taking medication, exercising, praying, correct food preparation, and performing house chores.

Conclusion: Lifestyle interventions to control hypertension for adults in a rural South African setting using physical activity promotion and dietary control must consider the beliefs related to hypertension control of this population.

STUDY THREE

Methodology: The third study was the design of a contextualised physical activity and diet intervention using behaviour change models. The intervention comprised of three components: a structured group education session, individualised physical activity education, and individualised dietary education over a period of 10 weeks. Participants were recruited via telephone.

Results: Feasibility parameters included recruitment of 30 participants with a self‐report hypertension diagnosis over one week, 80% participants retained to completion, 80% engaged with weekly monitoring calls. Acceptability was assessed qualitatively via face-to-face interviews to explore perceived expectations, benefits, motivation, and barriers concerning the intervention. Fidelity parameters included measures of adherence, dosage, quality of intervention delivery, and participant responsiveness. Secondary measures included blood pressure, body mass index, waist‐ hip ratio, urinary sodium, accelerometer‐measured physical activity, and 24‐hour diet recall.

Conclusion: This study offers a person-centred, sociocultural approach to hypertension control through adaptations to physical activity and dietary intake. This study will determine whether HYPHEN is feasible and acceptable and will inform changes to the protocol/focus that could be tested in a full trial.

STUDY FOUR

Methodology: The fourth study sought to evaluate the feasibility and acceptability parameters of HYPHEN.

Results: The evaluation demonstrated high level of feasibility, acceptability, and fidelity. Thirty (100% of target) participants were successfully recruited over two days, 28 (93%) participants were retained, and 28 (93%) provided complete data. Qualitative data demonstrated high acceptability. Fidelity measures demonstrated that adherence was high, dosage of intervention lasted as planned, no deviation was observed from the planned educational content, and all participants engaged with weekly telephonic calls.

Conclusion: Although deemed feasible and acceptable, some amendments are required to the intervention procedures that were carried out before a full trial can be rolled out.

Implications

This study provides the first known evaluation of a contextualized physical activity and diet intervention for hypertension control in rural South Africa. This study shows that a contextually developed intervention for hypertension control has a promise of success if rolled out in a larger trial.