Key Points:
- The global burden of hypertension is high and increasing, with high rates of underdiagnosis and undertreatment.
- This study implemented a multi-pronged implementation package of HTN treatment within the capital of Nigeria.
- Results showed significant improvement in BP control and successful uptake of the implementation package, specifically anti-HTN medication prescription.
- The investigators hope to scale up this intervention to all the major geopolitical regions within Nigeria.
The global burden of hypertension (HTN) is elevated and increasing: 1.4 billion adults around the world have HTN, according to World Health Organization (WHO) data. Despite the resultant high burden of HTN-related diseases, the global HTN cascade of care is not well implemented, with high rates of underdiagnosis, and therefore, undertreatment. Based on the WHO HEARTS technical package and Kaiser Permanente’s model, Ojji et al established the Hypertension Treatment in Nigeria (HTN) study to evaluate implementation and effectiveness of a multilevel implementation package across 60 primary care facilities in Abuja, Nigeria.
The study intervention took place across 60 primary care facilities in the region. The intervention comprised five components: 1) a standard treatment protocol (based on WHO recommendations), 2) patient registration and enrollment in a patient panel, 3) prioritization of fixed-dose combination anti-HTN therapy (single pill combination of lisinopril-hydrochlorothiazide), 4) team-based care led by community health workers, and 5) home blood pressure monitoring and health coaching. Also of note, medications were provided at free cost initially for 18 months, followed by a reduced cost sharing model thereafter.
The study’s methodology involved four months of quantitative and qualitative research to assess service availability, readiness, and acceptability of the intervention as above. This was followed by nearly one-year of baseline data collection among HTN patients (defined as SBP > 140, DBP > 90, or patients on BP lowering medication). Afterward the program was implemented with continual evaluation.
Co-primary effectiveness outcomes were change in the slope of monthly HTN treatment and control (BP<140/<90) between pre and post implementation. Secondary effectiveness outcomes were mean SBP and DBP and rates of combination medical therapy prescription. Co-primary implementation outcomes included several factors related to uptake of the intervention and cost of the implementation package. Safety outcomes included symptoms of low blood pressure, changes in serum potassium and serum creatinine, and serious adverse events.
Over 21,038 participants were enrolled with balanced populations in pre-implementation and implementation arm. The treatment rate (95% CI) increased from 76% (73%-78%) at baseline to 97% (97%-97%) in the latest 3-months (p<0.0001). The treatment rate increased from 91% to 97% during the implementation period (p<0.0001). The treatment rate changed by 1% per month during the pre-implementation period, and 0.1% during the implementation period; these rates are statistically different (p<0.0001). The control rate (95% CI) increased from 23% (20%-27%) at baseline to 56% (55%-56%) in the latest 3-months (p<.0001). The control rate increased from 37% to 56% during the implementation period (p=0.0001). The control rate changed by 1.6% per month during the pre-implementation period, and 0.5% during the implementation period; these rates are statistically different (p=0.008). 22% of participants enrolled in HomeBP were controlled at the beginning of enrollment period; this increased to 47% at the end of the enrollment period. Control among the HomeBP participants reached 54% as of October 2023.
The proportion of protocol fixed dose combination medications prescribed increased from 43% at baseline in 2020 to 90% in the last 3 months (p=0.003 non-linear); there was an increase from 83% to 90% during the implementation phase (p<.0001 non-linear). The proportion of FDC prescribed increased by 0.3% per month in the pre-implementation phase, and 0.4% during the implementation phase; these slopes are not statistically significantly different (p=0.95).
The trial found that there was significant increase in both treatment rates and control rates from pre-intervention to post-intervention. Regarding co-primary implementation, there was a statistically significant increase in the primary health centers of anti-HTN prescription. Secondary outcomes analysis is ongoing, with a mixed-methods approach.
In summary, the HTN Program led to significant increase in monthly average treatment and control of HTN, though changes were greatest in pre-implementation period, as well as significantly improved BP over the study period. There was also an increase in fixed-dose combination anti-HTN therapy, from baseline 43% to 97%. The team now seeks to scale up their HTN program and HEARTS implementation to Nigeria’s 6 geopolitical region.