Table 2.

Results of Quality Appraisal using the Quality In Prognosis Studies (QUIPS) Tool Summary

Author, year	Study participation	Study attrition	Prognostic factor measurement	Outcome measurement	Study confounding	Statistical analysis/reporting
Bruggeman 2007, Australia [28]	moderate	high	moderate	low	moderate	Low
Cristancho 2016, USA [15]	low	high	moderate	low	high	moderate
Deng, 2005, Taiwan [29]	low	high	high	high	high	high
Langer 2015, USA [30]	moderate	high	low	low	high	moderate
Lenze, 2007, USA [13]	low	low	low	low	moderate	moderate
Lenze, 2008, USA [31]	low	moderate	low	low	low	moderate
Lenze, 2005, USA [32]	low	low	low	low	high	high
Liu 2018, Taiwan [33]	low	moderate	moderate	low	moderate	high
Matheny, 2011, USA [34]	low	high	moderate	low	low	high
Shyu 2009, Taiwan [10]	low	low	moderate	low	high	high
Van der Ree, 2020, Netherlands [14]	low	moderate	low	low	high	low
Voshaar 2007, the Netherlands [35]	low	moderate	moderate	low	high	moderate