Prevalence of hypertension is high due to late detection and poor blood pressure control, with the resultant complications leading to high morbidity and mortality among adult population. As informal sectors like traders have insufficient access to structured health services, exploring the effectiveness of blood pressure education on knowledge of hypertension and blood pressure status is timely. Using a non-randomised experimental study design, this study assessed the effect of health education on knowledge and prevalence of hypertension among market traders in Abakaliki Ebonyi State, Southeastern Nigeria.
This study found that low proportion (one fifth) of the participants in the intervention and control group had overall good knowledge of hypertension at the beginning of the study. Knowledge of specific domains of hypertension like risk factors, complications, treatment and prevention was also low. This finding is comparable to similar studies of traders in Imo State Nigeria,19 and in sub-urban community of Auchi Edo State Nigeria20 and Egypt21 where comprehensive knowledge was lacking. The poor knowledge may be due to limited access to adequate health information as most informal sectors lack structured occupational health services.11 Interestingly, all the participants had heard about hypertension (awareness rate of 100%) which can be explained by the high proportion of participants that have at least a secondary education, and coupled with the fact that the study was carried out in urban setting where effect of electronic media-their main source of information is better felt. Unfortunately, the high awareness did not reflect on their level of knowledge; meaning that awareness alone does not imply knowledge.
After the blood education intervention, a significant increase was noted in the mean knowledge score and in the proportion of participants with overall good knowledge of hypertension in the intervention group (64% increase) but not in the control group. This finding is in concordance with a quasi-experimental study conducted in Nigeria12 where significant increase in knowledge level was reported after 3 months post programme. Similar studies carried out in China22 and Canada23 also reported that the overall knowledge of hypertension significantly improved among those that received educational programme. This improvement in knowledge of hypertension indicates the effectiveness health education intervention and as such, should be sustained.
This study found more than a third of the sampled trades have hypertension (38.8% and 36.2% in the intervention and control groups respectively); indicating high prevalence. This finding is comparable to previous studies on market traders in Enugu10 and Lagos24 which reported similar results. Much higher prevalence (66.4%) was reported in Ekiti, Southwestern Nigeria25 which may be explained by the older age group (> 40 years) studied, as aging has been linked to higher risk of hypertension.26 Contrary to our finding, similar studies have reported low prevalence of less than 20% among market traders in rural communities of Ijebu Ode, Ogun State27 and Osun State Nigeria28 which were attributed to minimal appearance of factors predisposing to western lifestyle in these rural communities.28 The high prevalence of hypertension noted in this study may be attributed to presence of risk factors of hypertension such as sedentary lifestyle and high salt and fatty diets which is often associated with market traders.10 This finding indicates high burden of undiagnosed hypertension which needs to be addressed as early detection is linked to possible prompt treatment and aversion of complications.
After the intervention, there were significant decrease in mean systolic and diastolic blood pressure and in the prevalence of hypertension among the intervention group but not in the control group. Similar studies in Nigeria,12 India29 and China13 reported that blood pressure variables improved significantly after health education intervention. Another study which evaluated the impact of workplace health promotion program on employees’ blood pressure reported that the systolic and diastolic blood pressure in the intervention subgroup decreased significantly, whereas no change was observed among the control group over the 6-year period.30 This shows that adequate health education and screening programme on hypertension can enhance risk modification leading to improved blood pressure status, increase detection rate and reduce cardiovascular risks.
In this study, the odds of having hypertension was three times higher among those that are 40 years and above compared to those below 40 years. The finding is consistent with results of previous studies which reported that aging was associated with increased prevalence of hypertension.21,31 Age has been recognized as a non-modifiable risk factor attributing to increased cardiovascular risk such as hypertension,32,33 an assertion supported by studies among adults in Kenya34 and occupational groups in India35,36 Potential reasons for this could be changes in the blood vessels causing arterial stiffness, decreased elasticity and vascular resistance which occurs with increasing age.37,38
The study found that those that are single are two and half times more likely to have hypertension compared to those that are married. This finding is consistent with previous studies which reported that divorced, separated and never married individuals have higher prevalence of hypertension compared to their married counterpart.39,40,41 The mechanism underlying the effect of marital status on hypertension are not entirely understood. Studies suggested explanations including psycho-pathological factors, neuroendocrine pathway, biological mediators and health behaviour.42 Another study viewed that married men have better sleep, less stress, better moods and have better diet compared to never married men.43
Those with good knowledge of hypertension were found to be three times less likely to have high blood pressure compared to those with poor knowledge. This finding is comparable to earlier studies in Nigeria3 and Pakistan44 which reported good knowledge as predictor of hypertension. Sufficient knowledge about hypertension in patient has been associated with greater treatment adherence and better management and blood pressure control.45,46 Studies have shown that gaps in knowledge in the form of health illiteracy are key hindrances to effectively prevent and treat hypertension and facilitates individuals to progress to poor health outcomes.47,48 Our finding indicates that improving knowledge can have positive influence on beliefs, attitude and behaviour towards management and control of hypertension. Good knowledge of hypertension will go a long way in helping to decrease its prevalence in Nigeria and Africa as a whole since situations may not be different in other parts of the continents.
Limitations of the study
The main limitation of the study was the short duration for the study as one cannot tell to what extent the effects of the intervention can be sustained nor the long-term impact of the intervention on prevention and control of hypertension.