Exploring the impact of different definitions of blood pressure control prevalence among adults receiving integrated HIV-hypertension services in Lilongwe

Ben A Banda¹, Kelvin Balakasi¹, Verwoed Kumwenda¹, Edith Gulule¹, Mayamiko Chimombo¹, Joseph Njala¹, Corrina Moucheraud², Sam Phiri^1,3, Khumbo Nyirenda¹, Risa M Hoffman⁴, Joep J van Oosterhout^1,4

1. Partners in Hope, Lilongwe, Malawi
2. New York University – School of Global Public Health, New York, United States
3. School of Global and Public Health, Kamuzu University of Health Sciences, Lilongwe, Malawi.
4. University of California Los Angeles, Department of Medicine, David Geffen School of Medicine, Los Angeles, USA

Corresponding Author: Joep J. van Oosterhout; joep@pihmalawi.com

Abstract
Introduction
Large variation exists in how blood pressure (BP) control is reported among people with HIV (PWH) and hypertension in the literature from sub-Saharan Africa.
Methods
At a large HIV clinic in Lilongwe, Malawi, we investigated how reported prevalence of BP control would change depending on the approach used to measure it. In a retrospective study, we compared a hypertension control definition based on cross-sectional (one-visit) BP measurements at the individual’s last clinic visit (approach A) with longitudinal observation over one year, where two or three of the most recent BP measurements were used to define control (approach B). Both approaches used the same threshold of <;140/90 mmHg for control.
Results
Among 167 adults on hypertension treatment and antiretroviral therapy, the mean age was 54 years, 62.3% were female, 60.4% overweight/obese, 98.7% had suppressed viral load (<;1,000 copies/mL), 9.6% had diabetes and 79.0% were on ≥2 antihypertensive drugs. Hypertension control was estimated to be 65.3% using approach A and 55.7% using approach B, a 9.6% difference (95% confidence interval 1.7-17.5%; p=0.017).
Conclusion
These findings suggest that use of a single-visit BP overestimates control and indicate that a standardized definition of BP control using longitudinal data will help generalizing results of studies on hypertension control in PWH.