ILD Associated With Higher Risk of COVID-19 Severity, Mortality

Interstitial lung disease (ILD) was shown to correlate with an increased risk of both COVID-19 severity and mortality, according to a recent meta-analysis.

Interstitial lung disease (ILD) significantly correlated with a higher risk for COVID-19 severity and mortality, according to the results of a recent meta-analysis published in International Immunopharmacology.

This meta-analysis aimed to explore the association between ILD and risk for COVID-19 severity and mortality. Certain factors, such as sex, age, and certain comorbidities, are risk factors for severe COVID-19, and they may then impact the link between ILD and COVID-19 severity and mortality. Therefore, researchers performed this meta-analysis based on risk factors-adjusted effect estimates.

Researchers searched PubMed, Web of Science, and EMBASE for articles published from January 1, 2020, to July 5, 2022. The keywords used were interstitial lung disease, interstitial pneumonia, COVID-19, 2019-nCoV, and SARS-CoV-2.

The meta-analysis included 16 studies and 217,260 patients with COVID-19. Researchers used a random-effects meta-analysis model to compute the poor effect size with 95% CIs.

Interstudy heterogeneity was assessed using the standard Cochran’s Q test and I2 statistics. To evaluate the stability of study results, a leave-one-out sensitivity analysis was used. Subgroup and meta-regression analyses of sample size, age, percentage of male patients, region, study design, setting, methods for adjustment, and factors for adjustment were conducted to assess the cause of heterogeneity. Egger’s linear regression and Begg’s rank correlation analyses were conducted to assess publication bias.

Based on adjusted effect estimates, the meta-analysis indicated preexisting interstitial lung disease and higher risk of COVID-19 severity as significantly associated. Preexisting ILD was also significantly associated with higher risk of COVID-19 mortality.

The subgroup analysis showed consistent results for each of the factors assessed. By region, this analysis also showed ILD to be correlated with a significantly higher risk for COVID-19 severity in Asia and Europe but not in North America.

Sample size, age, and region were indicated to be potential sources of heterogeneity, according to the meta-regression analysis, and the sensitivity analysis indicated the study results to be stable and robust. The Egger’s test and Begg’s test revealed no publication bias.

Limitations of this meta-analysis include the presence of heterogeneity. Also, the factors and methods for adjustment were not entirely consistent across the studies included in the meta-analysis; most studies included were retrospective, which may contain bias; and the number of studies included in the meta-analysis was small.

“In conclusion, this meta-analysis on the basis of adjusted effect estimates demonstrated that preexisting ILD was independently associated with significantly higher risk for COVID-10 severity and mortality," the researchers concluded. "Further prospective cohort studies with bigger sample size should be done to confirm the results in the future."


Wang Y, Hao Y, Hu M, Wang Y, Haiyan Y. Interstitial lung disease independently associated with higher risk for COVID-19 severity and mortality: a meta-analysis of adjusted effect estimates. Int Immunopharmacol. Published online July 27, 2022. doi:10.1016/j.intimp.2022.109088