Robot-assisted vs conventional lumbar interbody fusion: A systematic review and meta-analysis of perioperative, radiographic, and clinical outcomes

Table 6 Risk of bias assessment for observational studies (risk of bias in non-randomized studies of interventions)

Ref.	Confounding	Selection bias	Classification of interventions	Deviations from intended interventions	Missing data	Measurement of outcomes	Selection of reported result	Overall risk of bias
Wang et al[1], 2023	Low	Low	Low	Low	Low	Low	Low	Low
Tong et al[2], 2024	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Shafi et al[3], 2022	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Griepp et al[4], 2024	Moderate	High	Low	Low	Low	Low	Low	Moderate
Lin et al[5], 2022	Moderate	Moderate	Low	Low	Low	Low	Moderate	Moderate
Li et al[6], 2025	Moderate	Low	Low	Low	Low	Low	Low	Moderate
Heath et al[7], 2024	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Chang et al[11], 2022	Moderate	Low	Low	Low	Low	Low	Low	Moderate
Lai et al[15], 2022	High	Moderate	Low	Low	Low	Low	Moderate	Moderate
Zhang et al[20], 2019	High	High	Low	Low	Low	Moderate	Moderate	High
Zhang et al[21], 2019	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Chen et al[22], 2021	Moderate	Moderate	Low	Low	Low	Low	Moderate	Moderate
Cui et al[23], 2021	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Li et al[25], 2024	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Han et al[26], 2021	High	Moderate	Low	Low	Low	Moderate	Moderate	High
De Biase et al[27], 2021	High	Moderate	Low	Low	Moderate	Moderate	Moderate	High
Fayed et al[28], 2020	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Yang et al[29], 2019	Moderate	Moderate	Low	Low	Low	Low	Low	Moderate
Schatlo et al[30], 2014	High	Moderate	Low	Low	Low	Low	Low	Moderate
Li et al[31], 2024	Moderate	Low	Low	Low	Low	Low	Low	Moderate
Li et al[32], 2022	Moderate	Low	Low	Low	Low	Low	Low	Moderate