Hypertension remains the most common cardiovascular risk factor¹ and according to the WHO report of 2013, developing countries, especially sub-Saharan Africa, are at the epicentre of this epidemic, with 46% of adults in this region having the disease.² In South Africa, an estimated 46% of women and 44% of men above 15 years of age have hypertension.^3,4

Despite the availability of pharmacological treatments and access to health facilities, blood pressure (BP) control rates remain low globally and in South Africa only 24.5% – 57.0% of patients with hypertension are reportedly controlled.^{4,5,6,7,8,9,10,11} The reasons for poor BP control in sub-Saharan Africa are poorly understood and involve multiple, complex and varying factors depending on setting.⁷ This often includes a high burden of treatment (BOT).¹²

Burden of treatment is described as the tasks patients are required to perform to achieve optimal outcomes in the management of their diseases and the effects these on their functionality and well-being.^13,14 Studies outside of South Africa have reported that high BOT is associated with poor chronic disease control, including hypertension.^13,14,15,16 A high BOT therefore has potential for adverse outcomes both for the patient and the healthcare system,^13,14,15,16 such as poor patient adherence to treatment and health advice,^17,18,19 poor disease control,^14,19,20 increased hospitalisation,^21,22 increased mortality and morbidity, increased costs of healthcare,^15,16 and low quality of life.^23,24

In South African primary healthcare (PHC), most patients with chronic diseases of lifestyle have hypertension, and in Sedibeng District more than 60% present with the disease.²⁵ Despite this, no local study provides information on the magnitude of BOT and the effect of high BOT on the prevalent poor BP control amongst patients with hypertension. Knowing this is useful for developing effective and context-specific interventions for improving BP control in South African PHC. The aim of this study was therefore to assess the magnitude of BOT and determine its relationship with BP control among patients on treatment for hypertension at a large PHC facility in Sedibeng District, Gauteng province.

A total of 239 participants were enrolled. Most of the participants were white (54.20%), female (60.08%), aged 45–64 years (54.62%), married or cohabiting (56.30%) and had completed high school or more education (71.85%) (Table 1).

Only 43.28% (n = 103) of participants had a comorbidity with hypertension and of these 63.64% did not consider their hypertension more burdensome than the other comorbidity (Table 2).

The proportions of participants with controlled and uncontrolled BPs are shown in Table 3 and indicate that only 40.34% and 39.92% were controlled to targets at current visit and in the last 3 months, respectively. Participants who were black people and divorced were significantly more likely to have a higher SBP. However, participants who were single and male were significantly more likely to have a higher DBP.

The mean treatment duration was 113.8 months (Table 4). Participants who were widowed (p < 0.01), white (p = 0.03), aged 45–64 years (p = 0.04) and female (p = 0.04) were significantly more likely to have longer mean durations of treatment. There was no significant difference in the duration of treatment between participants with controlled BP and those uncontrolled. There was no significant association between sociodemographic characteristics and BP control.

The BOT scores are shown in Table 5. Most of the participants (75%) reported a low TBOT. The mean TBOT was 19.7 (out of a possible score of 140). Regarding the relationship between TBOT/BOT and BP control, TBOT was not significantly different amongst sociodemographic groups (Table 6). However, participants with uncontrolled BP were significantly more likely to have a higher score in BOT1 component (p = 0.04). Except for single participants who were significantly more likely to score higher than others (p < 0.01), there were no significant differences in TBOT scores across other sociodemographic groups. On further analyses, race was found to be significantly associated with item 3 of the TBQ that enquired how problematic was ‘the efforts you make not to forget to take your medications’ (p = 0.006). Similarly, age and marital status were significantly associated with item 11 (The financial burden associated with your healthcare [e.g. out-of-pocket expenses not covered by insurance] of the TBQ that enquired how problematic was ‘the financial burden associated with your healthcare’) (p = 0.007 and 0.034, respectively).

As far as the authors are aware, this is the first study to assess BOT and determine its relationship with hypertension control in South Africa. We found that most participants had suboptimal hypertension control (60%) but reported none or low TBOT (90%). Comorbidity was common amongst participants (43.3%) and amongst this group most (63.6%) did not consider hypertension to be more burdensome than the other health problems. Although there was no significant association between TBOT and hypertension control, participants with uncontrolled BP were significantly more likely to report higher scores in BOT associated with issues around medication regimen than those with controlled BP (p = 0.04).

The finding of prevalent suboptimal hypertension control in this study reiterates those of previous studies in South Africa and elsewhere,^4,5 and highlights the need to develop a scalable and sustainable intervention plan that targets factors that have been associated with poor BP control, including poor lifestyle behaviours (smoking, diet, alcohol, obesity, etc.), weak social support network and high BOT as responsible factors.^4,5,6 However, the current study finds contrary on BOT and suggests that high BOT may not play a significant role in hypertension control in the South African PHC setting. Rather, addressing problems related to medication regimen such as poor access to anti-hypertensives, irrational prescriptions secondary to poor healthcare providers’ adherence to evidence-based guidelines and poor patient adherence to medications and lifestyle changes may be key to improving hypertension control in this setting.²⁷ Medication-related problems often arise from fragmentations within the health system, complex drug regimen, poor communication between the clinician and the patient, patient’s physical or cognitive limitations, socioeconomic status and behaviours that make patients forget, run out or take their medications wrongly.²⁷ Efforts to address poor patient adherence must build on a robust doctor–patient relationship and respond to individual patient’s reason(s) for non-adherence, be sensitive to non-verbal cues, motivate the patient towards desired behaviours, take cognisance of the cognitive capacity of the individual patient, confirm patient’s understanding of the issues and have a reminder system.²⁷ Total BOT is a composite measure, and the finding of a low BOT score and lack of association with BP control are counter-intuitive in that these contradict reports of financial, health system and social barriers to accessing PHC services in South Africa. These barriers include long queues and transit times, high patient load, unavailability of medications, poor staff attitudes and poor physical access.^28,29 However, there are several possible explanations for this: firstly, medical services at the PHC level are free in South Africa³⁰ and may remove significant barriers to accessing care, including for hypertension. Secondly, significant strides have been made by the South African government to ensure that PHC clinics are located within 5 km of most residential areas and this is the case in the research setting. Thirdly, the research setting was peri-urban, and most participants were white and had high school certificate or higher – characteristics that are known to increase patient assertiveness and engagement with healthcare providers,^31,32 and may account for the reported low burden scores with navigating the health system.

Fourthly, hypertension is symptomless (even when poorly controlled)² and patients may not perceive a need for social support until complications that are physically debilitating ensue. In addition, most of the participants (56.30%) in this study were married or cohabiting and were likely to enjoy the benefits of social companionship. These may make participants report low BOT scores because social companionship ameliorates stress inherent in living alone, mitigates high BOT and improves treatment adherence and outcomes.^5,6,17 Not surprisingly, in this study, divorced and single participants were significantly more likely to have a higher mean SBP and DBP, respectively. However, this study did not find any association between BP control and marital status, which may imply that there may be factors within the marriage institution such as social support whose absence or presence drives this association rather than the marriage itself. Nonetheless, where social companionship is lacking, such as in the elderly with hypertension who live alone, community-based health peer groups and home visits by community health workers could be used to promote social and treatment support, ameliorate BOT and consequently improve BP control.

Comorbidity was common in this study; previous multi-morbidity studies and BOT outside our context reported it to impose a high BOT, worsen treatment adherence and result in poor disease control.^1,2,3,4,5 There is a need for BOT studies and multi-morbidity to be carried out in our context. However, this highlights the need for healthcare professionals to screen for co-existing illnesses and BOT, not only for clinical risk stratification and treatment.¹⁶ If a high BOT is found, resources for social and treatment support need to be recruited. However, healthcare professionals do not often respond to poor disease by assessing BOT.^16,19 Rather, they escalate and make treatment regimens more complex.^16,19 Clinicians should aim to understand the impact of the BOT imposed on their patients by the physical demands of the disease and comorbid condition(s), the complexity of drug prescriptions and the need for self-care. Reflecting on these may result in healthcare professionals being more patient-centred and rational in their prescribing behaviour.

The TBOT is low amongst patients with hypertension and does not have significant association with BP control. However, the association of poor BP control with higher BOT1 scores highlights the need for strengthening healthcare providers’ adherence to evidence-based guidelines, simplifying drug regimen and promoting patient adherence to treatment in South African PHC. The limitations of this study necessitate that longitudinal and nationally representative quantitative studies on BOT and BP control are required. Qualitative studies are also needed to gain an in-depth understanding of BOT, especially in the African context. The escalation of TBOT and adverse outcomes with comorbidity requires the inclusion of multi-morbid patients in these studies. Because the TBQ was adopted from a developed country, there is a need for tests of validation and appropriateness in African context.