Date of Award

January 2023

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Inci Yildirim


Introduction: Climate change may have a negative impact on respiratory illnesses, such as influenza. Diurnal temperature range (DTR), an indicator of climate change, is the difference between the maximum and minimum temperature within a day or a week. As the climate warms, global DTR decreases, though there might be regions where DTR increases instead. Previous literature conducted in non-U.S. regions found both positive and negative associations between DTR and influenza infections. A group especially vulnerable to the effects of DTR are children less than 5 years of age due to their less-developed thermoregulation capability. This study thus aimed to explore the association of DTR with pediatric influenza hospitalization rates in different U.S. states from 2009 to 2019 to further understand this relationship.

Methods: Utilizing weekly influenza hospitalization rates from the Center for Disease Control and Prevention (CDC)’s FluSurv-NET surveillance system and meteorological data from the National Oceanic and Atmospheric Administration (NOAA), we employed a distributed non-linear lag model and a generalized additive model using a quasi-Poisson distribution to examine the complex non-linear relationship between the two variables, adjusting for relative humidity, mean temperature, and precipitation.

Results: New York’s Albany and Rochester, Michigan, and California exhibited positive associations between DTR and pediatric influenza hospitalization rate (relative risk at maximum DTR was 3.06 (95% confidence interval (CI): 1.532 – 5.893), 1.97 (95% CI: 1.018 –3.812), 2.07 (95% CI: 1.185 – 3.601), and 1.69 (95% CI: 1.054 – 2.707), respectively). Additionally, there was a respective 1,403% (p = 0.007), 475% (p = 0.045), 569% (p = 0.011), and 344% (p=0.030) change in hospitalization rate for every 1°C increase in DTR.

Conclusions: Our results can be used to inform the development of an early warning system that can alert the potential impact of a significant increase in DTRs. With regard to climate change, if global DTR decreases as the climate warms, then our results suggest that hospitalization rates will decrease as well, though in regions where DTR increases, hospitalization rates might increase. Further research on the relationship between temperature variability and respiratory infections that utilizes more granular data and that considers other important meteorological factors, influenza strain type, and vaccination history is needed.


This is an Open Access Thesis.

Open Access

This Article is Open Access