Accuracy of a smartphone application for blood pressure estimation in Bangladesh, South Africa, and Tanzania

Charles Festo; Valerie Vannevel; Hasmot Ali; Tigest Tamrat; Getrud J Mollel; Tsakane Hlongwane; Kaniz A Fahmida; Kelsey Alland; María Barreix; Hedieh Mehrtash; Ronaldo Silva; Soe Soe Thwin; Garrett Mehl; Alain B Labrique; Honorati Masanja; Ӧzge Tunçalp

doi:10.1038/s41746-023-00804-z

Accuracy of a smartphone application for blood pressure estimation in Bangladesh, South Africa, and Tanzania

NPJ Digit Med. 2023 Apr 17;6(1):69. doi: 10.1038/s41746-023-00804-z.

Authors

Charles Festo^#¹, Valerie Vannevel^#^{2

3

4}, Hasmot Ali^#⁵, Tigest Tamrat^#⁶, Getrud J Mollel¹, Tsakane Hlongwane^{2

3

4}, Kaniz A Fahmida⁵, Kelsey Alland⁷, María Barreix^#⁸, Hedieh Mehrtash^#⁸, Ronaldo Silva⁸, Soe Soe Thwin⁸, Garrett Mehl⁹, Alain B Labrique^{7

9}, Honorati Masanja¹, Ӧzge Tunçalp⁸

Affiliations

¹ Ifakara Health Institute, Dar es Salaam, Dar es Salaam, United Republic of Tanzania.
² South African Medical Research Council Maternal and Infant Health Care Strategies Unit, Pretoria, South Africa.
³ Research Centre for Maternal, Fetal, Newborn and Child Health Care Strategies, University of Pretoria, Pretoria, South Africa.
⁴ Department of Obstetrics and Gynaecology, Kalafong Provincial Tertiary Hospital, Pretoria, South Africa.
⁵ The JiVitA Maternal and Child Health and Nutrition Research Project, Nasirabad, Keranipara, Rangpur, 5400, Bangladesh.
⁶ UNDP/UNFPA/UNICEF/World Bank Special Program of Research, Development and Research Training in Human Reproduction (HRP), Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland. tamratt@who.int.
⁷ Center for Human Nutrition, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
⁸ UNDP/UNFPA/UNICEF/World Bank Special Program of Research, Development and Research Training in Human Reproduction (HRP), Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
⁹ Department of Digital Health and Innovations, World Health Organization, Geneva, Switzerland.

^# Contributed equally.

Abstract

Undetected and unmonitored hypertension carries substantial mortality and morbidity, especially during pregnancy. We assessed the accuracy of OptiBP^TM, a smartphone application for estimating blood pressure (BP), across diverse settings. The study was conducted in community settings: Gaibandha, Bangladesh and Ifakara, Tanzania for general populations, and Kalafong Provincial Tertiary Hospital, South Africa for pregnant populations. Based on guidance from the International Organization for Standardization (ISO) 81,060-2:2018 for non-invasive BP devices and global consensus statement, we compared BP measurements taken by two independent trained nurses on a standard auscultatory cuff to the BP measurements taken by a research version of OptiBP^TM called CamBP. For ISO criterion 1, the mean error was 0.5 ± 5.8 mm Hg for the systolic blood pressure (SBP) and 0.1 ± 3.9 mmHg for the diastolic blood pressure (DBP) in South Africa; 0.8 ± 7.0 mmHg for the SBP and -0.4 ± 4.0 mmHg for the DBP in Tanzania; 3.3 ± 7.4 mmHg for the SBP and -0.4 ± 4.3 mmHg for the DBP in Bangladesh. For ISO criterion 2, the average standard deviation of the mean error per subject was 4.9 mmHg for the SBP and 3.4 mmHg for the DBP in South Africa; 6.3 mmHg for the SBP and 3.6 mmHg for the DBP in Tanzania; 6.4 mmHg for the SBP and 3.8 mmHg for the DBP in Bangladesh. OptiBP^TM demonstrated accuracy against ISO standards in study populations, including pregnant populations, except in Bangladesh for SBP (criterion 2). Further research is needed to improve performance across different populations and integration within health systems.

Grants and funding

001/WHO_/World Health Organization/International