To our knowledge, the current study is the first multi-level examination of hypertension risk in low- and middle-income countries. Like most traditional epidemiological studies that had examined traditional well-established individual-level risk factors, we found that increasing age, educational attainment, wealth status, overweight/ obesity, and cigarette smoking were associated with increased risk of hypertension. The findings revealed that differences between neighbourhoods and countries determine hypertension risk. The results show that the prevalence of hypertension is still relatively high in LMICs. Previous studies by Kibria et al.  & Chowdhury et al.  in cross-sectional studies revealed high hypertension prevalence in Bangladesh, Nepal, and other LMICs. The increase in the prevalence of hypertension had been linked to rapid urbanisation and unhealthy lifestyle changes, such as the consumption of unhealthy diets that include fast foods, sedentary behaviour and increased alcohol consumption .
After adjusting and controlling for the effects of the individual-, neighbourhood- and country-level factors, we observed that for every 10-year increase in age, there was an increase in the odds of developing hypertension. Our findings were consistent with Chowdhury et al.  & Hassan et al. . Both studies found that the prevalence of hypertension increases with increasing age and being affected by the place of residence, sex, education, wealth index, working status and body mass index. Ageing increases the risk of infection and diseases, which in turn elevate the risk of mortality .
The odds of developing hypertension increased with increasing levels of educational attainment and wealth index values. Respondents with secondary or higher education levels were more likely to develop hypertension than those with no education. Similarly, respondents from wealthier households were more likely to develop hypertension. Supporting this finding, Kibria et al. , Tareques  & Sanuade et al.  noted that the prevalence of hypertension was higher in urban individuals and those in higher socioeconomic classes (i.e., the highest wealth quintile) than in respondents from rural areas and the lowest wealth quintile. The odds of developing hypertension in higher socioeconomic classes and urban individuals can be attributed to several behavioural factors, such as unhealthy diet, cigarette use, and alcohol consumption are influenced by place of residence, wealth status and level of education . To address these risk factors, behaviour change programmes should be tailored to wealthier populations and individuals with higher educational attainment to reduce the incidence of hypertension in this group.
Our findings also revealed that Marital status is a significant independent predictor of hypertension. We found that currently married or ever married respondents had an increased chance of developing hypertension compared to respondents who reported never being married in LMICs. Supporting this evidence, Tuoyire & Ayetey  & Sanuade et al.  both studies established that being currently married or previously been married status increased the odds of developing hypertension in Ghanaian women. This could result from low income or inability to access health care facilities and much stress from daily struggle.
The association between weight gain and blood pressure has been well studied. We found that individuals who were overweight and obese were almost two and three times more likely to develop hypertension than those with normal body weight. Our result is consistent with studies carried out by Harshfield et al. , Rahman et al. , Taraque et al. , Chowdhoury et al. , Alkibria et al.  & Fottrell et al. . These studies confirmed that being obese or overweight is a traditional risk factor for hypertension. Rahman and colleagues estimated the prevalence of hypertension to be higher in urban areas than in rural areas. People living in urban areas may consume more calories and have sedentary lifestyle patterns that may increase BMI, thereby increasing their risk of developing hypertension.
We noted that individuals who reported financial problems assessing health care were at higher risk of developing hypertension than those financially stable. The lack of universal health insurance coverage has been a significant barrier to accessing health care facilities in most LMICs . The rapid increase in the prevalence of hypertension is due to low and current projected spending on health. Despite the high number of populations in these regions, only 0.4% of global health spending was in LMICs in 2016 .
The results of this study indicate that smoking is a vital determining factor with regard to developing hypertension. We observed that respondents who smoked cigarettes were more likely to have hypertension than those who did not smoke. This finding is consistent with that of Saladini et al. . The study revealed that the odds of developing hypertension are elevated in those who smoke. Tobacco smoking is associated with increased arterial wall stiffness, thereby increasing the risk of developing hypertension .
The study also found that the place of residence plays a significant role in determining the health outcome of individuals. Respondents living in the least deprived areas were more likely to develop hypertension than those in the most deprived areas. Chowdhury et al. , Kibra et al.  & Sanuade et al.  noted that place of residents had significant associations with hypertension in rural and urban regions among older people, wealthier people, females, those with diabetes and overweight individuals. Based on the distributions of these significant factors, it is highly likely that public health awareness campaigns targeted at deprived areas could contribute to controlling hypertension globally.
More crucially, the findings add to the body of knowledge by revealing those factors at the contextual level increase hypertension risk in addition to individual-level determinants. Researchers have recently become more interested in exploring the effects of contextual SES on CVD risk variables [11, 13]. Several studies have found that neighbourhood SES traits are inversely related to blood pressure reactivity, suggesting that individual and neighbourhood SES may be independent predictors of blood pressure [22, 29, 30, 33]. According to Matheson et al. , deprivation in the neighbourhood appears to be a stronger predictor of hypertension in women. Women living in high deprivation areas are 10% more likely to report having hypertension than males living in the same areas and women living in the least deprived areas. Liu and colleagues also discovered that variations in the prevalence of high blood pressure can account for between 44 and 53% of the variation in the prevalence of high blood pressure and that individuals living in disadvantaged physical and socioeconomic environments have a significantly higher risk of high blood pressure prevalence .
We found evidence of geographical clustering in the risk of hypertension. Differences between countries and neighbourhoods accounted for approximately 26 and 48% of the variation in hypertension, respectively. We also observed that respondents moving to a different neighbourhood or country with a higher risk of hypertension had an increased chance of developing hypertension. People from the same community are inherently more similar in terms of their current risk of developing hypertension than people from different neighbourhoods, i.e., the contextual phenomenon manifests itself as the clustering of the risk of hypertension within neighbourhoods. Researchers frequently use an ecological perspective to understand the risk of developing a disease [3,4,5]. The disease is viewed as a multidimensional phenomenon including the interaction of individual, family, community, and societal factors88 in this paradigm. The framework considers the many levels of societal organisation as well as their impact on disease. An individual lives in a household unit, which is part of a community that is governed by the policies of a state or national government. Every level of the social hierarchy can impact an individual’s illness risk. The ecological model also promotes a complete public health strategy that tackles not only an individual’s risk of becoming a hypertension risk.
Based on these contextual findings, we might infer that there is some evidence for a possible neighbourhood and country contextual phenomenon shaping a common individual hypertension risk. These results highlight the importance of implementing public health preventive measures at the high-risk person level and at the high-risk neighbourhood level. Interventions that target an individual’s social and physical settings and health care systems are required to eliminate or reduce hypertension risk. These interventions must be multidimensional, i.e., they must take place at multiple levels simultaneously or in close succession . Changes in behaviour, such as eating better foods; legislative changes, such as raising taxes on unhealthy foods or drinks; changes in the delivery of health services; and environmental changes, such as making healthy food more accessible, are all possible outcomes of multi-level interventions . Community-based programmes, which connect communities and health systems and involve a variety of treatments like education and outreach, self-management, and home-based care, have emerged as a viable way to close access gaps [7, 31, 41] According to previous studies, community-based hypertension screening and case management strategies can save money while also improving outcomes [21, 25].
Further research is needed to construct novel risk scores for hypertension that include both individual and contextual factors to identify people at higher risk for developing hypertension and examine opportunities for the improved use of preventive interventions and the targeted delivery of proactive, personalised treatment. The current methods do not account for the underlying contextual factors that contribute to hypertension. There are significant health and economic benefits to early diagnosis, proper care, and effective hypertension control. Treating complications necessitates expensive measures that deplete the budgets of both individuals and governments. Similarly, additional decomposition studies may provide more information about important factors that could explain the differences in the risk of hypertension among high-risk individuals and those living in high-risk locations.
Some study limitations should be considered when interpreting our findings. First, we could not measure the length of time participants had lived in their current neighbourhoods and the degree of their exposure to the environment. Thus, we could not determine whether the associations of neighbourhood characteristics with current hypertension were due to cumulative effects. Second, the data we used were cross-sectional; hence, we were unable to determine causal inferences with regard to the reported associations. Finally, DHS surveys do not collect information on household expenditures or incomes, which are established indicators used to measure wealth. Montgomery et al.  & Filmer  reported that the asset-based wealth index could only be used as a proxy indicator of household economic status. The results obtained from the direct measurement of income and expenditures where such data are available are more reliable and consistent. The number of participants from India included in the analysis was considerably greater than the numbers from other countries; therefore, the characteristics of those respondents may have influenced the risk factors identified.
Despite these limitations, the findings of our study are significant because the data used are from a large, population-based survey with high response rates covering 12 LMICs. The DHS is a nationally representative survey that allows the drawing of conclusions across countries. The DHS data were collected using the same approach in all participating countries, allowing comparisons across countries.
In conclusion, socioeconomic position with regard to individual, compositional and contextual measures was independently associated with the risk of developing hypertension. Based on these findings, it is highly likely that these countries will benefit immensely from multi-level hypertension prevention strategies that address the different contextual risk factors explored in the study. Further studies could explore how these strategies could help reduce the incidence of hypertension and other related comorbidities, such as diabetes, coronary heart failure, obesity, etc., in the general population.