AUTHOR=Hao Chongqi , Zhao Zhiyang , Zhang Peijun , Wu Bin , Ren Hao , Wang Xuchun , Qiao Yuchao , Cui Yu , Qiu Lixia 

TITLE=Application of improved harmonic Poisson segmented regression model in evaluating the effectiveness of Kala-Azar intervention in Yangquan City, China

JOURNAL=Frontiers in Public Health

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1326225

DOI=10.3389/fpubh.2024.1326225

ISSN=2296-2565

ABSTRACT=Background: The Centre for Disease Control and Prevention in Yangquan, China, has taken a series of preventive and control measures in response to the increasing trend of Kala-Azar. In response, we propose a new model to more scientifically evaluate the effectiveness of these interventions. Methods: We obtained the incidence data of Kala-Azar from 2017 to 2021 from the Centre for Disease Control and Prevention (CDC) in Yangquan. We constructed Poisson segmented regression model, harmonic Poisson segmental regression model, and improved harmonic Poisson segmented regression model, and used the three models to explain the intervention effect respectively. Finally, we selected the optimal model by comparing the fitting effects of the three models.The primary analysis showed an underlying upward trend of Kala-Azar before intervention (incidence rate ratio [IRR]: 1.045, 95% confidence interval [CI]:1.027 to 1.063, P< 0.001). In terms of long-term effects, the rise of Kala-Azar slowed down significantly after the intervention (IRR:0.960, 95%CI:0.927 to 0.995, P=0.026), and the risk of Kala-Azar increased by 0.3% for each additional month after intervention (β1+β3=0.003, IRR=1.003). The results of the model fitting effect showed