Table 2.

Risk of bias assessment (using PROBAST) based on four domains across 51 studies that created prediction models for coronavirus disease 2019

Authors	Risk of bias
	Participants	Predictors	Outcome	Analysis
Hospital admission in general population
DeCaprio et al8	High	Low	High	High
Diagnosis
Original review
Feng et al10	Low	Unclear	High	High
Lopez-Rincon et al35	Unclear	Low	Low	High
Meng et al12	High	Low	High	High
Song et al30	High	Unclear	Low	High
Yu et al24	Unclear	Unclear	Unclear	High
Update 1
Martin et al41	High	High	High	High
Sun et al40	Low	Low	Unclear	High
Wang et al43	Low	Unclear	Unclear	High
Wu et al45	High	Unclear	Low	High
Zhou et al46	Unclear	Low	High	High
Diagnostic imaging
Original review
Barstugan et al31	Unclear	Unclear	Unclear	High
Chen et al26	High	Unclear	Low	High*
Gozes et al25	Unclear	Unclear	High	High
Jin et al11	High	Unclear	Unclear	High†
Jin et al33	High	Unclear	High	High*
Li et al34	Low	Unclear	Low	High
Shan et al28	Unclear	Unclear	High	High†
Shi et al36	High	Unclear	Low	High
Wang et al29	High	Unclear	Low	High
Xu et al27	High	Unclear	High	High
Song et al23	Unclear	Unclear	Low	High
Zheng et al38	Unclear	Unclear	High	High
Update 1
Abbas et al47	High	Unclear	Unclear	High
Apostolopoulos et al48	High	Unclear	High	High
Bukhari et al49	Unclear	Unclear	Unclear	High
Chaganti et al50	High	Unclear	Low	Unclear
Chowdhury et al39	High	Unclear	Unclear	High
Fu et al51	High	Unclear	Unclear	High
Gozes et al52	High	Unclear	Unclear	High
Imran et al53	High	Unclear	Unclear	High*
Li et al54	Low	Low	Unclear	High
Li et al55	High	Unclear	High	High*
Hassanien et al56	Unclear	Unclear	Unclear	High*
Tang et al57	Unclear	Unclear	High	High
Wang et al42	Low	Unclear	Unclear	High
Zhang et al58	High	Unclear	High	High
Zhou et al59	High	Unclear	High	High*
Prognosis
Original review
Bai et al9	Low	Unclear	Unclear	High
Caramelo et al18	High	High	High	High
Gong et al32	Low	Unclear	Unclear	High
Lu et al19	Low	Low	Low	High
Qi et al20	Unclear	Low	Low	High
Shi et al37	High	High	High	High
Xie et al7	Low	Low	Low	High
Yan et al21	Low	High	Low	High
Yuan et al22	Low	High	Low	High
Update 1
Huang et al60	Unclear	Unclear	Unclear	High
Pourhomayoun et al61	Low	Low	Unclear	High
Sarkar et al44	High	High	High	High
Wang et al42	Low	Low	Low	High
Zeng et al62	Low	Low	Low	High

PROBAST=prediction model risk of bias assessment tool.

^*Risk of bias high owing to calibration not being evaluated. If this criterion is not taken into account, analysis risk of bias would have been unclear.

^†Risk of bias high owing to calibration not being evaluated. If this criterion is not taken into account, analysis risk of bias would have been low.