Picture this, it’s a frigid January morning and you’re rushing to catch the bus that will transport you to another day in first grade. You almost make it out the door until your mother demands that you cannot leave the house without a winter jacket or you will suffer the consequences of catching a cold. A recent study suggests that this myth we were all so skeptical of as children, may actually be true. Through an analysis of the seasonal patterns through cold and warm weather patterns, the findings suggested that the amount of emergency department (ED) visits and inpatient (IP) admissions are influenced strongly by the colder seasons. In this study, researchers from Emory University found that the cold weather, especially the cold shock waves, impacts pneumonia and influenza hospitalizations specifically in the area where the study was performed, Atlanta, Georgia. Becoming educated on the relation between colder weather rolling around and illnesses circulating can provide us with information on how to remain healthy throughout those colder months.
As curiosity arose about the relation of colder weather to the human immune system, a study was organized to further that research. The study was led by researchers Morgan A. Lane, Maria Walawender, Erik A. Brownsword, Siyan Pu, Eri Saikawa, Colleen S. Kraft, and Robert E. Davis. It was published on March 20, 2022, on ScienceDirect titled “The Impact of Cold Weather on Respiratory Morbidity at Emory Healthcare in Atlanta”. It examined data over the years 2009 to 2019 in the Emory Healthcare data warehouse through the ED and IP data. In the analysis, we looked at the cases of pneumonia and influenza during the winter months and the peaking pattern. Specifically, the study was done on the influenza virus and observed patients eighteen years and older while also taking into consideration demographic data such as age, sex, race, and ethnicity.
To examine the statistics curated from this study, the researchers used the Charlson Comorbidity Index (CCI), a system created to predict a patient’s risk of death within one year of hospitalization (Lane et al. 2022). The index they used was categorized into mild, moderate, or severe conditions on a scale from 1 to 3. An individual with a score of 3 was put in the high-risk group. They also used the international classification of disease data which is used to code and classify mortality data from a death certificate (CDC 2021). The cold days were defined as the days where the temperature was at least one standard deviation below the 30-year mean from the years 1981 to 2010. The cold waves were declared at a minimum of three cold days along with two days in a row where that lowest temperature was not once exceeded. They found that in 2010 there were ten cold waves which was the highest frequency found over the course of the entire research span (Lane et al., 2022). In 2012 and 2016 there was only one cold wave. During the study, the data suggested that there was a spike in ED visits as a result of these cold shocks, not necessarily during them. “The odds of an ED visit during a cold wave were decreased by 7-8% as compared to the odds during the control periods” (Lane et al. 2022). Directly after the cold wave, the number of visits went up by 11%. The research study concluded that the colder weather did have an influence on ED visits and IP admissions from 2009 to 2019. At the beginning of the cold wave, the visits and admissions decreased but peaked right after as a result of everyone’s immune systems adjusting to combat the cold. This is very similar to other research studies that show cold weather having a lagging effect on respiratory diseases, giving the illnesses times to incubate for 1 to 6 days after infection (Spiga et al. 2016).
This study is important on a larger scale because it will allow our healthcare systems to prepare better for the impact of cold waves on staff. For example, increasing the number of staff on deck during those peak times (Lane et al. 2022). As a result, we will be able to balance treating the stationary patients during these peak times as well as the individuals who come in from the cold shock. It is also important to prioritize those who are compromised. This is extremely important information for the general public to be aware of to personally be able to prepare for these times when the risk of infection is at its highest. If this information is more accessible to the general public, people will care for their bodies more attentively when they know they are at higher risk of infection.
This study was organized very well, and the outcome was extremely impressive. They simply observed the statistics of patients at three hospitals in Atlanta without getting involved in any of the individuals’ personal lives or disclosing any information about their specific conditions. As someone who is not necessarily educated in anything related to this field and in general, I was still able to understand the outcome and steps of this study. I do believe that in the future this study could be replicated but not repeated the same since it was over a specific period and solely in Atlanta. I do think there are limitations with this study because Atlanta, compared to other global areas, is a warmer climate year-round, so looking at statistics of cold shocks strictly is risky. On the other hand, when your body adjusts to living in a certain environment, the cold shock is relative to the weather you are used to. This makes me wonder how this study would differ if it was performed in a colder climate. I think this source is very reliable and I thought it was a great idea for them to study the data for that organized length of time.
It would be very beneficial for these researchers to perform this study again but in a different location. This would allow them to compare the information they retrieve to their previous study done in Atlanta and see how the influence of the climate differs. They can also adjust this study to be more specific to a certain sickness and possibly a shorter period. Research studies such as this one open our minds to being more conscious of how to care for our bodies. It also makes us more inclined to be aware of when our bodies are most vulnerable to catching a cold. If this information is taken differently, it is a fear that people will overreact and not go out during these peak times which will result in weakened immune systems in the long run. This study provides us with valuable information and allows us to conclude that adding an extra layer of clothing as we are leaving our homes in colder weather might do more than we think when preventing contagious illnesses.
References:
Lane MA, Walawender M, Brownsword EA, Pu S, Saikawa E, Kraft CS, Davis RE. 2022. The impact of cold weather on respiratory morbidity at Emory Healthcare in Atlanta. Science of The Total Environment. 813:152612. doi:10.1016/j.scitotenv.2021.152612. [accessed 2022 Sep 8]. https://www.sciencedirect.com/science/article/pii/S0048969721076907#.
Spiga R, Batton-Hubert M, Sarazin M. 2016. Predicting Fluctuating Rates of Hospitalizations in Relation to Influenza Epidemics and Meteorological Factors. Shaman J, editor. PLOS ONE. 11(6):e0157492. doi:10.1371/journal.pone.0157492.
ICD – Classification of Diseases, Functioning, and Disability. 2019. https://www.cdc.gov/nchs/icd/index.htm.
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