Is rule of halves still an occurrence in South India: Findings from community-based survey in a selected urban area of Puducherry

BACKGROUND: The objective of the present study was to assess the applicability of the rule of halves in an urban population of Puducherry, South India. We also aimed to find the correlates associated with undiagnosed hypertension to facilitate targeted screening. METHODOLOGY: We derive our observation from a community-based cross-sectional study conducted using the World Health Organization STEPwise approach to surveillance in urban slum of Puducherry during 2014–15. Blood pressure (BP) was measured for all the study subjects (n = 2399), and the subjects were classified as hypertensive using Joint National Committee 8 criteria, systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mmHg and/or known hypertensives and/or treatment with antihypertensive drugs. Controlled hypertension was defined as SBP <140 mmHg and DBP <90 mmHg. RESULTS: Of 2399, 799 (33.3%; 95% confidence interval [CI]: 31.4%–35.2%) adults were found to have raised BP by any means (known and unknown hypertensives). Of the 799, 367 (15.3%; 95%CI: 13.9%–16.8%) of study participants were known hypertensives. Of the known hypertensives, 74.7% (274/367) were put on treatment (drugs and or lifestyle modification), and 80% (218/274) were on regular treatment. Higher proportions of men were found to have undiagnosed hypertension compared to women (26.1 vs. 19.8%, P < 0.001). Similarly, adult from below poverty line (23.8 vs. 20%, P < 0.001), unskilled laborer (26.6 vs. 20%, P < 0.001), and literacy less than middle school (12.3 vs. 23%, P < 0.001) had more undiagnosed hypertension. CONCLUSION: In the selected urban area of Puducherry around one-third of the adult populations are having hypertension, including the 54% of undiagnosed hypertension. Adults from the vulnerable subgroups such as lower level of literacy, below poverty line, and unskilled work are found to have higher proportions of undiagnosed hypertension.