# Pain Complaints and Intubation Risk in COVID-19 Patients: A Retrospective Cross-Sectional Analysis

## TL;DR

This study finds that hospitalized COVID-19 patients who report pain are less likely to need intubation, suggesting pain complaints may be a sign of better prognosis.

## Contribution

The study is the first to show a negative correlation between pain complaints and intubation risk in hospitalized COVID-19 patients using a large dataset.

## Key findings

- Pain complaints in hospitalized COVID-19 patients were associated with a lower likelihood of intubation.
- Specific pain types like myalgia and headache showed the strongest negative correlation with intubation.
- The study used over 2.4 million data points to analyze the relationship between pain and intubation.

## Abstract

Purpose

In late 2019, the SARS-CoV-2 virus spread to become a worldwide pandemic with continued impact today. The disease severity is categorized based on age, comorbid conditions, and respiratory symptoms, but the clinical significance of pain reports and their correlation with life-sustaining treatment is not addressed much in the literature. The purpose of this study is to investigate the relationship between pain reports in patients with COVID-19 and the likelihood of intubation.

Methods

A retrospective cross-sectional analysis was performed compiling representative billing codes for pain complaints using the Epic Cosmos data set, a HIPAA limited data set of more than 226 million patients from 236 health systems using Epic software. For validation of this method, three months of institutional-specific Cosmos billing code data were compared to chart-reviewed pain complaints at a university health system. After validation, the data was broadened to include the entire Cosmos database from February 1, 2020 through April 15, 2023 for patients with confirmed COVID-19 infections seen in emergency rooms or an inpatient ward. Using billing codes, these patients were divided into different pain groups: abdominal pain, chest pain, myalgia, headache, or none of these, and then further subdivided based on intubation status. Lastly, patients were divided by age: <18 years, 18 to <40 years, 40 to <50 years, 50 to 65 years, and ≥65 years of age. Pearson's chi-square analyses were performed to investigate the relationship between pain symptoms and intubation and further performed to assess variations by age subgroup. Odds ratios (ORs) of the data were calculated in the same manner.

Results

We investigated 2,491,770 data points in our analysis of COVID-19 positive emergency room and inpatient cases. When comparing the presence of all pain types combined and intubation by the chi-square test, the p-value (p) was <0.00001, suggesting that a relationship exists between pain and intubation. OR analysis showed that those with pain complaints were less likely to be intubated with OR 0.58 (95% confidence interval (CI) 0.57 to 0.59, p <0.0001). Pain subgroups similarly showed reduced likelihood of intubation: abdominal pain, OR of 0.61 (95% Cl: 0.59 - 0.62), chest pain, OR of 0.86 (95% Cl: 0.85 - 0.88), myalgia, OR of 0.26 (95% Cl: 0.24 - 0.27) and headache, OR of 0.31 (95% CI: 0.29 - 0.32).

Conclusions

Due to the wide variability in COVID-19 infection symptoms, it is difficult to identify a single risk factor that correlates with an increased likelihood of intubation. Our cross-sectional examination of 2.4 million data points for COVID-19 patients in the emergency department or inpatient settings found that pain complaints were negatively correlated with emergency intubation. Given this, the absence of pain reports in hospitalized COVID-19 patients may imply poor prognosis; however, further research is needed to determine whether the absence of pain is indeed a poor prognostic indicator and if so, hospitalized COVID-19 patients without pain warrant close monitoring.