|Year : 2022 | Volume
| Issue : 3 | Page : 269-275
Is the rule of halves in hypertension valid uniformly across India? A cross-sectional analysis of national family health survey-4 data
Mohd Maroof1, Nafis Faizi2, Pruthu Thekkur3, Sonika Raj4, Sonu Goel5
1 Assistant Professor, Department of Community Medicine, Rani Durgavati Medical College, Banda, Uttar Pradesh, India
2 Assistant Professor, Department of Community Medicine, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, India
3 Senior Operational Research Fellow, Centre for Operational Research, International Union Against Tuberculosis and Lung Disease (The Union), Paris, France
4 Public Health Masters Program, School of Medicine, University of Limerick, Limerick, Ireland
5 Professor, Department of Community Medicine and School of Public Health, Postgraduate Institute of Medical Education and Research, Chandigarh, India
|Date of Submission||10-Dec-2021|
|Date of Decision||20-May-2022|
|Date of Acceptance||03-Jun-2022|
|Date of Web Publication||22-Sep-2022|
Professor of Health Management, Department of Community Medicine and School of Public Health Post Graduate Institute of Medical Education and Research, Chandigarh; Adjunct Clinical Associate Professor, Public Health Masters Program School of Medicine and Health Research Institute (HRI), University of Limerick
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Hypertension is widely prevalent across India. The rule of halves is commonly used to describe the attrition and gaps in the care cascade of hypertension management across detection, availing treatment, and having controlled blood pressure (BP) on treatment. Objectives: Using nationally representative data, we aimed to assess the rule of halves in hypertension management in different states of India and across sociodemographic, health system, and personal factors. Methods: A descriptive analysis of secondary data from the National Family Health Survey-4 was conducted. We included 770,662 individuals (112,122 men and 658,540 nonpregnant women) of 15–49 years of age. The proportion of individuals not aware of hypertension status among those with high BP, known hypertensives not availing of treatment, and uncontrolled BP among those on treatment were expressed as percentage with a 95% confidence interval (CI). Results: Of those with high BP, 48.5% (95% CI: 47.8%–49.3%) were not aware of their hypertensive status. Among known hypertensives, 72% (95% CI: 71.2%–72.8%) had not availed treatment for hypertension. Among those on treatment, 39.8% (95% CI: 38.7%–40.9%) had uncontrolled hypertension. Conclusion: The rule of halves of India shows that the National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases, and Stroke has made relatively good progress with the detection of hypertension and achieving BP control among those on treatment. However, with three-fourth of known hypertensives not availing treatment, more dividends from the detection of hypertension efforts could be realized. The program needs to especially focus on ensuring the treatment for those detected with hypertension.
Keywords: Awareness, hypertension, India, National Family Health Survey-4, noncommunicable disease, rule of halves
|How to cite this article:|
Maroof M, Faizi N, Thekkur P, Raj S, Goel S. Is the rule of halves in hypertension valid uniformly across India? A cross-sectional analysis of national family health survey-4 data. Indian J Public Health 2022;66:269-75
|How to cite this URL:|
Maroof M, Faizi N, Thekkur P, Raj S, Goel S. Is the rule of halves in hypertension valid uniformly across India? A cross-sectional analysis of national family health survey-4 data. Indian J Public Health [serial online] 2022 [cited 2022 Nov 26];66:269-75. Available from: https://www.ijph.in/text.asp?2022/66/3/269/356602
| Introduction|| |
Noncommunicable diseases (NCDs) are the leading cause of death, with 80% of deaths occurring in low- and middle-income countries such as India. Globally, disability-adjusted life years (DALY) due to hypertension increased by 88.9%, amounting to 39.41 million in 2016. The great India blood pressure (BP) survey puts the overall burden of hypertension in India at 30.7%.
Hypertension is the most common cardiovascular disorder but is often silent and invisible. Its amenability to treatment underscores the enormous health and economic benefits of its screening and adequate management. Unfortunately, due to poor primary health care, absence of continuum of care, unawareness, and sociodemographic inequities, many people even after the age of 40 years have never got their BP measured or do not seek appropriate treatment and rule of halves still has significance in India. Given the nature of this major risk factor, undetected hypertension and inadequate management have a significant social cost, as money spent on its complications accounts for one-fifths of total health expenditure.
The rule of halves in hypertension was coined in the 1970s. It pertains to the notion that most hypertensives are unaware of their hypertensive status while most of the aware hypertensives are untreated, and most of the treated hypertensives have inadequately controlled blood pressure. Isolated studies in India have documented its presence in hypertension,,,, but have been limited in sample size, design, and context. India is a hugely populous federal union comprising 28 states and eight union territories, where health is a state subject and variations are expected in disease burden as well as health system response. In 2010, the National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases, and Stroke (NPCDCS) recommended screening of hypertension for all people of 30 years and above. The rule of halves thus is also a measure of impact for the NPCDCS program. For a comprehensive status of rule of halves in hypertensive management, we analyzed the results of the National Family Health Survey-4 (NFHS), which was conducted in 2015 − 2016 and involved 601,509 households across every state and union territory of India.
This study takes stock of the pattern of rule of halves across the different states of India and its implications across sociodemographic, health system, and personal factors.
| Materials and Methods|| |
The NPCDCS program is the major program for NCDs, providing early diagnosis and management of hypertension along with other NCDs through NCDs cells at the different levels of health-care system. The care provision for diabetes and hypertension is available at the primary health centers, making it accessible and affordable.
Due to the epidemiological transition toward NCDs, the program recommends screening of all individuals ≥30 years for hypertension to ensure the early detection and adequate management for limiting untoward life-threatening cardiovascular diseases. The program covered only 100 districts in 2010 − 2012, later by 2015, it was implemented in about 200 districts, and currently, it has been universalized in the country.
We did a cross-sectional analysis of the data from the NFHS-4 conducted during January 2015 − December 2016. The data were requested and received from the Demographic and Health Surveys (DHSs) Program. The NFHS-4 was carried out in two rounds using the stratified two-stage sampling method. The survey covered all 29 states, 07 union territories, and 640 districts in India as per the 2011 census. A total of 601,509 households with 699,686 women and 112,122 men (random subsample of 15% of households) were interviewed using the four survey questionnaires (Household Questionnaire, Woman's Questionnaire, Man's Questionnaire, and Biomarker Questionnaire) surveyed in 17 local languages using computer-assisted personal interviewing. We included 770,662 individuals (112,122 men and 658,540 nonpregnant women) of 15–49 years of age for our analysis.
NFHS-4 was conducted under the stewardship of the Ministry of Health and Family Welfare, coordinated by the International Institute for Population Sciences, Mumbai, and implemented by 14 field agencies, including three Population Research Centers. Technical assistance for NFHS-4 will again be provided by ICF International, the USA with the major financial support from the United States Agency for International Development and Ministry of Health and Family Welfare, Government of India. The entire methodology details can be obtained from the official report of NFHS-4.
Data access and variables
Datasets for the analysis were downloaded from the DHS data source after providing the title and study brief. The variables used in the study were unknown hypertension, not taking treatment, and uncontrolled BP; sociodemographic factors (state, area of residence-rural/urban, age, sex, education, current marital status, BPL card, and wealth index); health system factors (health scheme/insurance coverage and place of treatment); and personal factors (diabetes, smoking, alcohol, and body mass index). The case definitions of the variables as used in the study were as follows:
The BP was measured three times at an interval of 5 min each. The first reading was discarded and the average of the last two was taken. Hypertension was labeled if the average systolic BP was ≥140 mmHg or average diastolic BP was ≥90 mm Hg or both.
The respondent was labeled as aware if he/she answered yes for the question “Told had high BP on two or more occasions by doctor or other health professional.” The aware hypertensives were identified as “known hypertensives” in this research.
The respondent was labeled as taking treatment if he/she answered yes for the question “Currently taking a prescribed medicine to lower BP.”
The respondent was labeled as control if he/she answered yes for the question “Currently taking a prescribed medicine to lower BP,” and if average systolic BP was ≤140 mmHg and average diastolic BP was ≤90 mmHg.(average - average of last two readings).
The study was ethically approved by the Institute's Ethical Committee, Postgraduate Institute of Medical Education and Research, Chandigarh (PGI/IEC/2021/001139).
The analysis was done for 112,122 men and 658540 nonpregnant women 15–49 years of age. Sampling weights were computed during the analysis to account for the differential probabilities of participation and selection in the survey. Stratification and clustering at the level of PSUs were accounted with weights before calculating the percentages with a 95% confidence interval (CI) for the above-mentioned outcomes of interest. Data analysis was performed using IBM SPSS Statistics version 20.0 (IBM Corp., Armonk, NY, USA) for the data management and statistical analysis.
| Results|| |
The result was analyzed for 770,662 individuals (112,122 men and 658,540 nonpregnant women) of 15–49 years of age. The rule of halves pertains to three levels: awareness, treatment, and control of hypertension. We found that 48.5% (95% CI: 47.8%–49.3%) hypertensives did not know their hypertensive status; among known hypertensives, 72% (95% CI: 71.2%–72.8%) did not seek treatment; and among hypertensives on treatment, 39.8% (95% CI: 38.7%–40.9%) had uncontrolled hypertension [Figure 1].
Rule of halves across the states
The proportion of hypertensives not knowing their hypertension status ranged between 40% and 50%, with most of the states with a larger population having this proportion >50%. Only Haryana, Tamil Nadu, Telangana, Mizoram, and Jammu and Kashmir fared better with <40% unknown hypertensives. As far as treatment of known hypertensives is concerned, 72% of known hypertensives in India did not seek treatment. Except Goa, every state in India had more than 50% of known hypertensives not seeking treatment. While the treatment seeking was poor, majority of those on treatment (60.2%) had controlled hypertension in India. Among the states, Punjab and the North-eastern states of Sikkim, Arunachal Pradesh, Assam, Manipur, and Nagaland had more than 50% uncontrolled hypertensives among those on treatment [Table S1].
Knowledge on hypertension status across sociodemographic characteristics
Among the sociodemographic factors, more males were unknown hypertensives (63.1% [61.5%–64.7%]) as opposed to females (45.8% [45%–46.5%]). Unknown hypertensives were more seen in the age group of 15–19 years (51.3% [49.5%–53.1%]) and 40–49 years (51.3% [50.5%–52.2%]), residents of rural localities (51.5% [50.6%–52.3%]), and lower in people having higher education (41.2% [39.6%–42.8%]) and complete secondary education (42.1% [40.3%–43.8%]). While only (42.5% [41.1%–43.8%]) of the individuals belonging to the richest wealth index had unknown hypertensive status, unknown hypertensives were (62.6% [61.4%–63.8%]) in those of poorest wealth index. Christians (44.1% [41.1%–47.1%]) and Sikhs (45.3% [42.6%–48.8%]) had lower unknown hypertensives as opposed to others. Current married had the lowest unknown hypertensives (47.7% [47%–48.5%]) as compared to others [Table 1].
Among the health system factors, families with members not covered with a health scheme or health insurance had more unknown hypertensives (51% [50.3%–51.7%]). Regardless of preference to private or public treatment, unknown hypertensives prevalence was similar with a prevalence of 47.6% [46.6%–48.6%] among those who preferred public and 48.9% [48%–49.8%] among those who preferred private treatment [Table 2].
Among the personal factors, lowest unknown hypertensives were found among obese people (53.8% [52%–55.6%]) as opposed to others, whereas higher unknown hypertensives were seen among alcoholics (61.5% [58.9%–64.1%]), nonsmokers (86.9% [86.1%–87.7%]), and nondiabetics (48.8% [48%–49.6%]) [Table 3].
Treatment seeking among hypertensive across sociodemographic characteristics
More than 50% of individuals were not seeking treatment across all sociodemographic variables [Table 1]. Similarly, more than 50% of individuals were not seeking treatment across all health system variables [Table 2]. Similarly, more than 50% of individuals were not seeking treatment across all personal variables excluding diabetes, where <50% diabetes did not seek treatment [Table 3].
Blood pressure control among hypertensive across sociodemographic characteristics
Among the sociodemographic factors, uncontrolled hypertension was highest in the age group of 40–49 years (48.9% [47.3%–50.4%]). Uncontrolled hypertension in males was >50% (51.2% [47.8%–54.6%]), whereas in females, it was <50% (38.4% [37.2%–39.5%]). Uncontrolled hypertension was <50% in both rural and urban areas. Sikhs and Jain had uncontrolled hypertension >50%, whereas rest all had <50% uncontrolled hypertension. Uncontrolled hypertension was found in <50% across all education groups, marital status, and socioeconomic class [Table 1].
Among health system factors, uncontrolled hypertension was seen in <50% among those on treatment in both public (40.3% [38.7%–42.2%]) and private (39.1% [37.6%–40.7%]) facility. Similarly, uncontrolled hypertension was seen in <50% irrespective of health scheme/insurance coverage [Table 2].
Among the personal factors, uncontrolled hypertension was higher in obese (48% [45.3%–50.7%]) and overweight (47.5% [45.3%–49.6%]) people, uncontrolled hypertension was >50% among alcoholics (53.9% [48.5%–59.3%]), and ~50% in diabetics (50% [46.3%–53.7%]) and nonsmokers (49.8% [46.3%–53.3%]) [Table 3].
| Discussion|| |
The objective of the article was to take stock of the rule of halves situation in India across different states and their implications with respect to sociodemographic, health system, and personal factors.
About 48.5% (47.8%–49.3%) of hypertensives did not know about their hypertensive status. While this is less than half (50%), the proportion in most large Indian states was more than 50% [Figure 1]. In terms of unknown hypertensives, the rule of halves is present in most parts of India, as has been the case in the past in Karnataka, urban Chennai, and Pondicherry in the South as well as in the rural North. However, the nationwide presence of such a wide proportion of unknown hypertensives is a matter of concern. Further, about 72% of the known hypertensives were not seeking treatment. The poor treatment seeking behavior despite the awareness of hypertension reflects a missed opportunity with implications on economic and productivity loss. Whether this is a missed opportunity due to inadequate advice by the health workers who diagnosed hypertension or because of other health system factors such as poor accessibility and affordability for continued care is difficult to ascertain from the survey. Among those who were seeking treatment, the prevalence of uncontrolled hypertension was 39.8%, lower than the traditional 50% for the rule of halves. In essence, the rule of halves is present in India in terms of unknown hypertensives and untreated hypertensives, more so in the latter. However, among the treated hypertensives, the rule of halves is not present.
Some of the studies from around the world, and also from the parts of India, suggest a shift from the rule of halves. Unknown hypertensive males had a higher proportion than females, the exact reasons for which could not be assessed in this research. Expectedly, rural population, lower educational status, and wealth index had a higher proportion of unknown hypertensives. Unknown hypertensives were higher in the 15–19 years age group other than 40 to 49 years age group, reflecting the rising trend of hypertension among young adults as reflected in the other research as well. This also questions the well-held belief that hypertension is restricted to later ages or with co-morbidities alone. Among the health system factors, the families without health insurance or scheme coverage had a higher proportion of unknown hypertensives reflecting the implications of an inaccessible or unaffordable health system. While we did find no difference between people's preference for private or public treatment, this preference is generic and could be a response to any disease treatment-chronic or infectious as well as hospitalization or OPD-based treatment, as is the case in hypertension. Interestingly, among personal factors, alcoholics, nondiabetics, and nonsmokers had a higher proportion of unknown hypertensives, whereas the lowest was among the obese. This clearly reflects the awareness and recognition of hypertension among the risk groups is poor except for the obese.
The fact that most known hypertensives are not taking treatment across all the socio-demographic variables, is a matter of huge concern. Similarly, even among personal factors, diabetics were the only people who sought treatment in a proportion more than 50%. Clearly, untreated hypertensives who know about their hypertension status need more information and awareness about the dangers of hypertension and the benefits of timely management of this silent and asymptomatic killer.
On the other hand, uncontrolled hypertension was more in males and 40–49 years' age group population apart from obese/overweight people, diabetics, and alcoholics. While the latter conditions do have an implication on BP treatment and control, it is difficult to ascertain the reasons behind a higher proportion of males and 40–49 years' age group having more untreated hypertensives.
Our study has three significant implications. First, most hypertensives in the larger states of India have undiagnosed hypertension, and its nationwide presence is very high at 48.5%. Moreover, this is despite the fact that the highest prevalence age group of the elderly (>49 years) was not being included in the study. Second, the higher proportion of unknown hypertensives in younger age groups is a matter of concern, as the NPCDCS only screens for hypertension at 30 years and above. Third, screening of hypertension or awareness of hypertension status is clearly not beneficial when most of the known hypertensives (72%) are not seeking any treatment. Fourth, the NFHS can consider an additional question (whether the doctor had asked you to start treatment for hypertension in the past) for those with a past history of high BP to better depict the care cascade in hypertension management.
| Conclusion|| |
There have been improvements in the detection of hypertension post-NPCDCS program. However, the presence of untreated but known hypertensives across all sociodemographic and personal factors needs to be addressed with urgency. Given the huge benefits for the patient, social cost, and health expenditure, more urgent intervention is needed to ameliorate the condition. The program needs to especially focus on ensuring treatment for those detected with hypertension.
While this research appraises the nationwide presence of rule of halves alongwith reflections on states, it also has its limitations. First, the survey results are applicable only to individuals aged between 15 and 49 years (reproductive age group) and cannot be generalized to all the age groups. Hypertension could be more in the older age groups and the results must be seen with the lens of adults of 15–49 years age in India only, excluding older adults. Secondly, the health system determinants are not captured well in the survey to critically determine its association with hypertension diagnosis or management. Thirdly, the individuals were ascertained as “known hypertensives” if they had answered “yes” for the question “Told had high BP on two or more occasions by doctor or other health professional.” Although unlikely, a miscommunication about prehypertensive state by the health provider could lead to false assumption of known hypertension. Since all the individuals labelled as “known hypertensives” were considered eligible for treatment, the proportion “not on treatment” was calculated with “known hypertensives” as the denominator. Such miscommunication on prehypertensive state could have a bearing on the estimation of “not availing treatment”.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Global Burden of Disease Collaborative Network. Global Burden of Disease Study 2016 (GBD 2016) Reference Life Table. Seattle, United States of America: Institute for Health Metrics and Evaluation (IHME); 2017.
Ramakrishnan S, Zachariah G, Gupta K, Shivkumar Rao J, Mohanan PP, Venugopal K, et al.
Prevalence of hypertension among Indian adults: Results from the great India blood pressure survey. Indian Heart J 2019;71:309-13.
Faizi N, Ahmad A, Khalique N, Shah MS, Khan MS, Maroof M. Existence of rule of halves in hypertension: An exploratory analysis in an Indian village. Mater Sociomed 2016;28:95-8.
Wilber JA, Barrow JG. Hypertension – A community problem. Am J Med 1972;52:653-63.
Shanthirani CS, Pradeepa R, Deepa R, Premalatha G, Saroja R, Mohan V. Prevalence and risk factors of hypertension in a selected South Indian population-the Chennai Urban Population Study. J Assoc Physicians India 2003;51:20-7.
Hadaye R, Kale V, Manapurath RM. Strategic implications of changing rule of halves in hypertension: A cross-sectional observational study. J Family Med Prim Care 2019;8:1049-53.
] [Full text]
Ismail IM, Nandy S, Adhikari S, Tm R, Gupta D, Deeptha M, et al.
Time to switch to 'rule of three-quarters' from 'rule of halves' in hypertension? A descriptive study from Dakshina Kannada, South India. Cureus 2021;13:e13142.
Ministry of Health and Family Welfare. National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases & Stroke (NPCDCS) Operational Guidelines (Revised: 2013-17) Directorate General of Health Services Ministry of Health & Family Welfare Government of India 2013; 2017. p. 1-78.
International Institute for Population Sciences (IIPS) and ICF. National Family Health Survey (NFHS-4) 2015-16: India. Mumbai: IIPS; 2017. p. 1-671.
DHS. The DHS Program – Quality Information to Plan, Monitor and Improve Population, Health, and Nutrition Programs. The DHS Program; 2018. Available from: https://dhsprogram.com/
. [Last accessed on 2021 Jun 28].
Joshi SR, Shah SN. Control of blood pressure in India: Rule of halves still very much valid. J Assoc Physicians India 2003;51:151-2.
Deepa R, Shanthirani CS, Pradeepa R, Mohan V. Is the 'rule of halves' in hypertension still valid?-Evidence from the Chennai Urban Population Study. J Assoc Physicians India 2003;51:153-7.
Kar SS, Kalaiselvi S, Archana R, Saya GK, Premarajan KC. Is rule of halves still an occurrence in South India: Findings from community-based survey in a selected urban area of Puducherry. J Postgrad Med 2017;63:232-6.
] [Full text]
Lerner AG, Bernabe-Ortiz A, Gilman RH, Smeeth L, Miranda JJ. The “rule of halves” does not apply in Peru: Awareness, treatment, and control of hypertension and diabetes in rural, urban, and rural-to-urban migrants. Crit Pathw Cardiol 2013;12:53-8.
Marques-Vidal P, Tuomilehto J. Hypertension awareness, treatment and control in the community: Is the 'rule of halves' still valid? J Hum Hypertens 1997;11:213-20.
Rao V, Daniel A. Application of the “rule of halves” for hypertension as an assessment tool in an urban slum at Davangere. Natl J Community Med 2014;5:333-6.
[Table 1], [Table 2], [Table 3]