TABLE 2

Risk of bias assessment summary using the Quality in Prognosis Studies tool

First author [ref.]Study participationStudy attritionPrognostic factor measurementOutcome measurementStudy confoundingStatistical analysis reporting
Holverda [21]LowModerateLowLowModerateLow
Boerrigter [18]LowLowLowLowModerateLow
Thirapatarapong [11]LowModerateLowLowHighLow
Adir [12]LowLowModerateLowHighModerate
Skjørten [28]LowLowLowLowLowLow
Xiong [29]LowLowLowLowModerateLow
Blanco [10]LowModerateModerateLowModerateLow