Observational Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Crit Care Med. Mar 9, 2022; 11(2): 102-111
Published online Mar 9, 2022. doi: 10.5492/wjccm.v11.i2.102
Association of latitude and altitude with adverse outcomes in patients with COVID-19: The VIRUS registry
Aysun Tekin, Shahraz Qamar, Romil Singh, Vikas Bansal, Mayank Sharma, Allison M LeMahieu, Andrew C Hanson, Phillip J Schulte, Marija Bogojevic, Neha Deo, Simon Zec, Diana J Valencia Morales, Katherine A Belden, Smith F Heavner, Margit Kaufman, Sreekanth Cheruku, Valerie C Danesh, Valerie M Banner-Goodspeed, Catherine A St Hill, Amy B Christie, Syed A Khan, Lynn Retford, Karen Boman, Vishakha K Kumar, John C O'Horo, Juan Pablo Domecq, Allan J Walkey, Ognjen Gajic, Rahul Kashyap, Salim Surani, The Society of Critical Care Medicine (SCCM) Discovery Viral Infection and Respiratory Illness Universal Study (VIRUS): COVID-19 Registry Investigator Group
Aysun Tekin, Romil Singh, Mayank Sharma, Diana J Valencia Morales, Rahul Kashyap, Salim Surani, Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, United States
Shahraz Qamar, Post-baccalaureate Research Education Program, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, United States
Vikas Bansal, Marija Bogojevic, Simon Zec, John C O'Horo, Ognjen Gajic, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, United States
Allison M LeMahieu, Andrew C Hanson, Phillip J Schulte, Division of Clinical Trials and Biostatistics, Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN 55905, United States
Neha Deo, Alix School of Medicine, Mayo Clinic, Rochester, MN 55905, United States
Katherine A Belden, Division of Infectious Diseases, Thomas Jefferson University Hospital, Philadelphia, PA 19107, United States
Smith F Heavner, Prisma Health, Greenville, SC 29605, United States
Margit Kaufman, Englewood Health, Englewood, NJ 07631, United States
Sreekanth Cheruku, Divisions of Cardiothoracic Anesthesiology and Critical Care Medicine, Department of Anesthesiology and Pain Management, UT Southwestern Medical Center, Dallas, TX 75390, United States
Valerie C Danesh, Center for Applied Health Research, Baylor Scott and White Health, Dallas, TX 75246, United States
Valerie M Banner-Goodspeed, Department of Anesthesiology, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States
Catherine A St Hill, Allina Health, Minneapolis, MN 55407, United States
Amy B Christie, Department of Critical Care, Atrium Health Navicent, Macon, GA 31201, United States
Syed A Khan, Division of Critical Care Medicine, Mayo Clinic Health System, Mankato, MN 56001, United States
Lynn Retford, Karen Boman, Vishakha K Kumar, Society of Critical Care Medicine, Mount Prospect, IL 60056, United States
John C O'Horo, Division of Infectious Diseases, Mayo Clinic, Rochester, MN 55905, United States
Juan Pablo Domecq, Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, United States
Allan J Walkey, Pulmonary Center, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Evans Center of Implementation and Improvement Sciences, Boston University School of Medicine, Boston, MA 02118, United States
Salim Surani, Department of Pulmonary and Critical Care Medicine, Texas A&M University, Bryan, TX 77807, United States
Author contributions: Tekin A and Kashyap R prepared the first draft of this manuscript; Qamar S, Singh R, Bansal V, Sharma M, Bogojevic M, and Deo N contributed to the design of the study and the data collection; LeMahieu AM, Hanson AC, and Schulte PJ conducted the analysis of the data; Zec S, Valencia Morales DJ, Belden KA, Heavner SF, Kaufman M, Cheruku S, Danesh VC, Banner Goodspeed VM, St. Hill CA, Christie AB, and Khan SA contributed to data collection; Retford L and Boman K helped with the data retrieval; Kumar VK, O’Horo JC, Domecq JP, Walkey AJ, Gajic O, and Surani S reviewed, edited, and provided critical feedback on the manuscript.
Institutional review board statement: The study approval was obtained by the Mayo Clinic IRB.
Conflict-of-interest statement: None of the authors have any conflict of interest to disclose.
Data sharing statement: Data would be available from Dr. Aysun Tekin and Dr. Rahul Kashyap.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Salim Surani, FACP, FCCP, MD, MPH, Doctor, Professor, Department of Pulmonary and Critical Care Medicine, Texas A&M University, 8447 Riverside Pkwy, Bryan, TX 77807, United States. srsurani@hotmail.com
Received: October 4, 2021
Peer-review started: October 4, 2021
First decision: December 9, 2021
Revised: December 21, 2021
Accepted: February 23, 2022
Article in press: February 23, 2022
Published online: March 9, 2022
Processing time: 149 Days and 9.7 Hours
ARTICLE HIGHLIGHTS
Research background

The coronavirus disease 2019 (COVID-19) has taken the world by storm. Several factors were attributed to the spread of the virus including altitude and latitude. We studied the relationship of location with unfavorable patient outcomes in COVID-19.

Research motivation

There were variations in the case and fatality rates in different regions of the world. Using a large cohort, we aimed to assess if latitude or altitude had an impact on the disease course of the COVID-19 on the individual patient level.

Research objectives

To study the association of certain aspects of location with unfavorable outcomes in COVID-19.

Research methods

An observational study using the Virus COVID-19 Registry was used to analyze for mortality within 28 d of admission and hospital length of stay. Adjusting for baseline parameters and admission date, multivariable regression modeling was utilized.

Research results

Twenty-two thousand one hundred eight patients from 21 countries were included. Mortality within 28 d of hospital admission was found to be 25%. The median number of hospital-free days among all included patients was 20 days. Despite the linear association between mortality within 28 d of hospital admission and hospital-free days and increasing latitude being significant, indicating that adverse disease outcomes were more frequent in locations further away from the Equator, the association was not significant after adjusting for baseline characteristics. A non-linear association between altitude and 28-day mortality was seen.

Research conclusions

There seemed to be an association of latitude with mortality within 28 d of admission and hospital-free days, which was nonsignificant when adjusted for baseline characteristics.

Research perspectives

The differences observed in previous epidemiological studies may be due to ecological fallacy rather than implying a causal relationship with environmental factors at the individual level.