Table 1 Baseline characteristics of included studies
Study | Duration | Country | DII Measurement (FFQ) | Median DII score | COVID-19 Cases | Total participants | Mean/ median age (years) | Sex: male (proportion) | OR | 95% CI | OR (severity) | 95% CI | Adjusted for | Study Quality (NOS score) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Zhao et al. 2023 | January 2020 to February 2021 | UK | 45- items | −0.43 | 11,288 | 196,154 | 57 | 0.553 | 1.05 | 1.03–1.06 | 1.11 | 1.05–1.16 | Age, sex, race/ethnicity, deprivation index, history of heart disease, cancer, type 2 diabetes, smoking status, physical activity, sleep duration | 7 |
Moludi et al. 2021 | June to July 2020 | Iran | 138-items | 0.80 | 60 | 120 | 59.3 | 0.7 | 3.06 | 1.07–8.72 | 1.14 | 0.95–1.36 | Age, sex, BMI, diabetes, blood pressure | 6 |
Firoozi et al. 2022 | March 2020 to June 2020 | Iran | 116-items | -0.51 | 133 | 455 | 40.3 | 0.547 | 2.86 | 2.30–3.55 | Age, sex, weight,BMI, waist-to hip circumference rate, educational level, smoking | 6 | ||
Tavassoli et al. 2023 | May 2020 to January 2021 | Iran | 168-items | -0.08 | 100 | 200 | 39 | 0.50 | 1.08 | 0.92–1.27 | Age, sex, diabetes disease, pulmonary disease, BMI | 5 | ||
Mohajeri et al. 2022 | Up to July 2021 | Iran | 138-items | -1.25 | 500 | 1000 | 41.5 | 0.51 | 1.63 | 1.54–1.72 | Age, sex, chronic heart disease, hypertension, diabetes, dysplidaemia, educational level | 5 |