Post vaccination acute kidney injury and other renal complications after COVID-19 and influenza vaccination

Table 1 Risk of bias assessment of included studies using the risk of bias in non-randomised studies - of interventions tool

Ref.	Vaccine	Confounding	Selection of participants	Exposure classification	Deviations from intended interventions	Missing data	Outcome measurement	Selection of reported results	Overall risk of bias
Kamei et al[10], 2023	COVID-19	Serious	Moderate	Low	Moderate	Low	Low	Moderate	Serious
Waldman et al[11], 2023	COVID-19	Serious	Serious	Low	Low	Moderate	Low	Moderate	Serious
Sanders et al[12], 2022	COVID-19	Serious	Moderate	Low	Low	Moderate	Low	Moderate	Serious
Wan et al[13], 2022,	COVID-19	Low	Moderate	Low	Low	Moderate	Moderate	Low	Moderate
Yechezkel et al[14], 2023	COVID-19	Moderate	Moderate	Low	Low	Moderate	Moderate	Low	Moderate
Choi et al[15], 2024	COVID-19	Moderate	Low	Low	Low	Low	Serious	Moderate	Moderate
Lionaki et al[16], 2024	COVID-19	Moderate	Moderate	Low	Low	Low	Moderate	Low	Moderate
Poster Abstracts[17], 2022	COVID-19	Serious	Moderate	Low	Low	Moderate	Low	Moderate	Serious
Carrillo et al[18], 2023	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Chen et al[19], 2023	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Diebold et al[20], 2022	COVID-19	Low	Low	Low	Low	Low	Low	Low	Low
Canney et al[21], 2022	COVID-19	Low	Low	Low	Low	Low	Low	Low	Low
Ota et al[22], 2023	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Wang et al[23], 2024	COVID-19	Low	Low	Low	Low	Low	Low	Low	Low
Sun et al[24], 2024	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Nagatsuji et al[25], 2024	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Aoki et al[26], 2024	COVID-19	Serious	Serious	Low	Low	Moderate	Low	Moderate	Serious
Zhang et al[27], 2024	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Low	Moderate
Mazza et al[28], 2025	COVID-19	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Thepveera et al[29], 2025	COVID-19	Moderate	Moderate	Low	Low	Moderate	Low	Moderate	Moderate
Tsai et al[30], 2025	COVID-19	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Huang et al[31], 2025	COVID-19	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Ishimori et al[32], 2023	Influenza	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Hao et al[33], 2023	Influenza	Moderate	Low	Low	Low	Moderate	Moderate	Moderate	Moderate
Moghaddasi et al[34], 2013	Influenza	Serious	Serious	Low	Low	Moderate	Low	Moderate	Serious
Fernández-Ruiz et al[35], 2015	Influenza	Serious	Moderate	Low	Low	Moderate	Low	Moderate	Serious
Cohet et al[36], 2016	Influenza	Low	Low	Low	Low	Low	Moderate	Low	Low
Dos Santos et al[37], 2016	Influenza	Low	Low	Low	Low	Moderate	Low	Low	Low
Miskulin et al[38], 2018	Influenza	Moderate	Low	Low	Low	Moderate	Low	Moderate	Moderate
Klifa et al[39], 2019	Influenza	Serious	Serious	Moderate	Low	Moderate	Moderate	Moderate	Serious
Ishimori et al[40], 2021	Influenza	Moderate	Moderate	Low	Low	Moderate	Moderate	Low	Moderate
Kumar et al[41], 2023	Influenza	Moderate	Moderate	Low	Low	Moderate	Low	Low	Moderate
Levison et al[42], 2022	Influenza	Low	Low	Low	Low	Low	Low	Low	Low
Shih et al[43], 2018	Influenza	Moderate	Low	Low	Low	Low	Low	Low	Moderate
Cho et al[44], 2024	Influenza	Low	Low	Low	Low	Low	Low	Low	Low
Zhuo et al[45], 2026	Influenza	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Chen et al[46], 2025	Influenza	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Liao et al[47], 2022	Influenza	Moderate	Low	Low	Low	Low	Low	Low	Moderate
Sheth et al[48], 1979	Influenza	Serious	Serious	Low	Moderate	Moderate	Moderate	Moderate	Serious
Jeffs et al[49], 2015	Influenza	Low	Low	Low	Moderate	Low	Low	Low	Low
Chen et al[50], 2022	Influenza	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Pabico et al[51], 1974	Influenza	Serious	Moderate	Low	Moderate	Low	Low	Moderate	Serious
Reynales et al[52], 2012	Influenza	Serious	Moderate	Low	Low	Low	Moderate	Low	Serious
Gwynn et al[53], 2020	Influenza	Serious	Moderate	Low	Moderate	Low	Moderate	Moderate	Serious
Ishimori et al[54], 2020	Influenza	Moderate	Moderate	Low	Moderate	Low	Low	Low	Moderate
Zawiasa-Bryszewska et al[55], 2025	Influenza	Moderate	Moderate	Low	Moderate	Moderate	Moderate	Low	Moderate

COVID-19: Coronavirus disease 2019.