JMIR Publications

ABSTRACT

Background:

The outbreak of the COVID-19 pandemic was followed by reduced utilization of routine diagnostic exams. Along with other pandemic-related factors, this may have influenced detected clinical conditions.

Objective:

The study aimed to analyze the impact of COVID-19 on the use of outpatient medical imaging services and clinical findings therein, specifically focusing on the time period after the launch of the Israeli COVID-19 vaccination campaign. In addition, the study tested whether the observed gains in clinical findings may be linked to exposure to COVID-19 infection, hospitalization (indicative of COVID-19 complications), or vaccination.

Methods:

Our dataset included 572,480 ambulatory medical imaging patients in a national health organization, from January 1, 2019 to August 31, 2021. We compared different measures of medical imaging utilization and clinical findings therein, before and after the surge of the pandemic, to identify significant changes. We also inspected the changes in the rate of abnormal findings during the pandemic after adjusting for changes in medical imaging utilization. Finally, for imaging classes that showed increased rates of abnormal findings, we measured the causal associations between COVID-19 infection/hospitalization/vaccination and the risk for abnormal finding. To allow adjustment for a multitude of confounding factors, we used causal inference methodologies.

Results:

After the initial drop in the utilization of routine medical imaging due to the first COVID-19 wave, the number of these exams has increased, but with lower proportions of older patients, patients with comorbidities, women, and vaccine-hesitant patients. Furthermore, we observed significant gains in the rate of abnormal findings, specifically in musculoskeletal Magnetic Resonance (MR-MSK) and brain Computed Tomography (CT-brain) exams. These results also persisted after adjusting for the changes in medical imaging utilization. Estimated causal associations included: COVID-19 infection increasing the risk for an abnormal finding in a CT-brain exams (odds ratio [OR] of 1.4, with 95% confidence interval [CI] 1.1 to 1.7); and COVID-19-related hospitalization increasing the risk for abnormal findings in an MR-MSK exam (OR 3.1, 95% CI 1.9 to 5.3).

Conclusions:

The increase in the number of ambulatory imaging exams during the COVID-19 period was heterogenous, implying greater tendency to avoid medical imaging exams among patients at higher risk for COVID-19 complications: older patients, patients with comorbidities, and non-vaccinated patients. The observed gains in the rate of abnormal findings in MR-MSK and CT-brain could not be explained by the changes in the use of these exams. Our results suggest that patients with previous COVID-19 infection and hospitalization may have contributed to the observed gains in abnormal findings in MR-MSK and CT-brain exams, respectively.