METHODS: Electronic databases were searched until February 2024, for articles reporting on changes in symptom severity in DGBI patients during the COVID-19 pandemic. The proportion of DGBI patients who reported a change in their symptom severity were pooled using a random-effects model, and subgroup analyses were conducted to assess the effect of socio-cultural modifiers on symptom severity in DGBI.

KEY RESULTS: Twelve studies including 3610 DGBI patients found that 31.4% (95% CI, 15.9-52.5) of DGBI patients experienced symptom deterioration, while 24.3% (95% CI, 10.2-47.5) experienced improvement. Countries with high gross domestic product (GDP) had a 43.5% (95% CI, 16.3-75.2) likelihood of symptom deterioration, compared to 9.2% (95% CI, 1.4-42.2) in lower GDP countries. Similarly, countries with low COVID fatality rates had a 60.1% (95% CI, 19.7-90.3) likelihood of symptom deterioration, compared to 18.3% (95% CI, 7.8-36.9) in higher fatality rate countries. Countries with lenient COVID policies had a 58.4% (95% CI, 14.1-92.3) likelihood of symptom deterioration, compared to 19% (95% CI, 8.2-38.1) in countries with stricter policies. Patients in high vaccine hesitancy countries had a 51.4% (95% CI, 19.5-82.2) likelihood of symptom deterioration, compared to 10.6% (95% CI, 2.7-33.4) in low vaccine hesitancy countries.