<p>Estimation of Generalized Impact Fraction and Population Attributable Fraction of Hypertension Based on JNC-IV and 2017 ACC/AHA Guidelines for Cardiovascular Diseases Using Parametric G-Formula: Tehran Lipid and Glucose Study (TLGS)</p>

Abstract

An area of interest to health policymakers is the effect of interventions aimed at risk factors on decreasing the number of new cardiovascular disease (CVD) cases. The aim of this study was to estimate the generalized impact fraction (GIF) and population attributable fraction (PAF) of hypertension (HTN) for CVD in Tehran. Patients and Methods: In this population-based cohort study, 8071 participants aged ≥30 years were followed for a median of 16 years. A survival model was used to estimate the 10-and 18-year risk of CVD. JNC-IV and 2017 ACC/AHA guidelines were used to categorize blood pressure (BP). PAF and GIF were estimated in different scenarios using the parametric G-formula. Results: Of 7378 participants included in analyses, 22.7% and 52.3% were classified as hypertensive according to the JNC-IV and 2017 ACC/AHA guidelines, respectively. According to the 2017 ACC/AHA, the 10-year risk of CVD was 5.1% (4.3-6.0%), 8.9% (6.7-12.0%), and 7.1% (6.1-8.4%) for normal BP, elevated BP, and stage 1 HTN, respectively, and 20.8% (18.8-23.0%) for stage 2 of the 2017 ACC/AHA and JNC-IV. The PAF of stage 2 vs stage 1 and vs normal BP for CVD was 17.4% (11.5-21.8%) and 20.4% (14.6-26.4%), respectively. The GIF of 30% reduction in the prevalence of stage 2 HTN to stage 1 and to normal BP for CVD was 5.1% (3.4-6.6%) and 6.1% (4.4-8.0%), respectively. Based on JNC-IV, the PAF and GIF of 30% for CVD were 17.8% (12.7-22.9%) and 5.4% (4.0-6.9%), respectively. Conclusion: By reducing the prevalence of HTN by 30%, a remarkable number of new CVD cases would be prevented. In an Iranian population, the comparison of HTN cases with normal BP showed no association between stage 1 HTN and CVD, whereas elevated BP was a significant risk factor for the incidence of CVD.

Population attributable fraction estimates of cardiovascular diseases in different blood pressure levels in a large-scale cross-sectional study: a focus on prevention strategies and treatment coverage

“…Strikingly, it has been reported that a 10 mmHg lower SBP is associated with a 30–40% lower risk of stroke [32]. In addition, based on the 2017 ACC/AHA guideline, by a 30% reduction in the prevalence of hypertension, 6.1% of CVD cases could be prevented [33]. Also, in 2016, the approximate rate of Iranian participants who were aware of their hypertension were estimated at 37.1% regarding the 2017 ACC/AHA guidelines [24].…”

The potential impact fraction of population weight reduction scenarios on non-communicable diseases in Belgium: Application of the g-computation approach

“…The potential impact fraction (PIF), also called the generalized impact fraction (GIF), is another measure that allows to estimate the fractional reduction of cases that would occur from changing the current level of exposure in the population to some modi ed level (14). The PAF and the generalized impact fraction (GIF), both affected by the strength of the association between the disease and the risk factor as well as the prevalence of the risk factor, estimate the disease risk in the population in case of "complete withdrawal" and "partial reduction" of the exposure (15,16). The application of the traditional PAF or GIF for policymaking in this context is strongly limited by the rigors of complete elimination of the risk factor as well as the disadvantages of traditional methods based on standard regression models (7,17).…”