Cost-Effectiveness of a Digital Health Intervention for Screening and Managing Hypertension at Primary Care Level in Kenya: A Microsimulation Model
Author(s)
James O. Oguta, MSc.
PhD Student, University of Sheffield, Sheffield, United Kingdom.
PhD Student, University of Sheffield, Sheffield, United Kingdom.
OBJECTIVES: To evaluate the longterm cost-effectiveness of a digital-health enabled intervention for managing hypertension at primary healthcare level in Kenya compared to usual care.
METHODS: We developed an individual-level microsimulation model using a synthetic cohort of 100,000 adults aged 35 years and older, derived from the 2015 Kenya STEPS survey. Individuals were simulated over annual cycles for 50 years, tracking cardiovascular risk factors, incidence of myocardial infarction (MI), stroke, and death from CVD or other causes. The intervention effect—defined as the 12-month reduction in systolic blood pressure—was estimated using inverse probability of treatment weighting (IPTW). The WHO CVD risk equations for Eastern Sub-Saharan Africa were used to estimate annual risks of MI and stroke. Costs were assessed from a health system perspective, and health outcomes were reported in disability-adjusted life years (DALYs). Probabilistic sensitivity analysis (PSA) with 1,000 simulations was conducted. The model was implemented in R.
RESULTS: Over the 50-year horizon, the intervention averted 7,160 MI events, 10,060 stroke events, and 9,333 deaths, compared to 4,592 MIs, 7,178 strokes, and 6,186 deaths averted by usual care. Mean per-person health system costs were US$5,836 for the intervention arm and US$5,849 for usual care. The intervention resulted in a mean of 0.34 DALYs averted per person, compared to 0.23 DALYs in the usual care arm. The deterministic incremental cost-effectiveness ratio (ICER) was US$ -118.5 per DALY averted, indicating cost savings. PSA results confirmed robustness, with an average ICER of US$ -124 per DALY averted and a 100% probability of cost-effectiveness at a willingness-to-pay threshold of US$1,000 per DALY (approximately 50% of Kenya’s GDP per capita).
CONCLUSIONS: Preliminary findings suggest that the intervention is cost-saving and more effective than usual care for managing hypertension patients in Kenya. Ongoing model calibration, validation, and stakeholder consultations are expected to refine these estimates further.
METHODS: We developed an individual-level microsimulation model using a synthetic cohort of 100,000 adults aged 35 years and older, derived from the 2015 Kenya STEPS survey. Individuals were simulated over annual cycles for 50 years, tracking cardiovascular risk factors, incidence of myocardial infarction (MI), stroke, and death from CVD or other causes. The intervention effect—defined as the 12-month reduction in systolic blood pressure—was estimated using inverse probability of treatment weighting (IPTW). The WHO CVD risk equations for Eastern Sub-Saharan Africa were used to estimate annual risks of MI and stroke. Costs were assessed from a health system perspective, and health outcomes were reported in disability-adjusted life years (DALYs). Probabilistic sensitivity analysis (PSA) with 1,000 simulations was conducted. The model was implemented in R.
RESULTS: Over the 50-year horizon, the intervention averted 7,160 MI events, 10,060 stroke events, and 9,333 deaths, compared to 4,592 MIs, 7,178 strokes, and 6,186 deaths averted by usual care. Mean per-person health system costs were US$5,836 for the intervention arm and US$5,849 for usual care. The intervention resulted in a mean of 0.34 DALYs averted per person, compared to 0.23 DALYs in the usual care arm. The deterministic incremental cost-effectiveness ratio (ICER) was US$ -118.5 per DALY averted, indicating cost savings. PSA results confirmed robustness, with an average ICER of US$ -124 per DALY averted and a 100% probability of cost-effectiveness at a willingness-to-pay threshold of US$1,000 per DALY (approximately 50% of Kenya’s GDP per capita).
CONCLUSIONS: Preliminary findings suggest that the intervention is cost-saving and more effective than usual care for managing hypertension patients in Kenya. Ongoing model calibration, validation, and stakeholder consultations are expected to refine these estimates further.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EE167
Topic
Economic Evaluation, Epidemiology & Public Health, Medical Technologies
Disease
Cardiovascular Disorders (including MI, Stroke, Circulatory), No Additional Disease & Conditions/Specialized Treatment Areas