Research Article

Increased Sphingosine Kinase 1 Expression Is Associated with Poor Prognosis in Human Solid Tumors: A Meta-Analysis

Table 4

Risk of bias assessment using the GRADE instrument.

Quality assessmentQualityImportance
No. of studiesStudy designRisk of biasInconsistencyIndirectnessImprecisionOther considerations

OS
29Observational studiesNot seriousSeriousNot seriousNot seriousPublication bias strongly suspected; strong association; all plausible residual confounding would suggest spurious effect, while no effect was observed⨁⨁◯◯
Low
Our confidence in the effect estimate is limited

DFS
11Observational studiesSeriousSeriousNot seriousNot seriousStrong association; all plausible residual confounding would suggest spurious effect, while no effect was observed⨁⨁◯◯
Low
Our confidence in the effect estimate is limited

Question: “Is Upregulation of SPHK1 associated with poor prognosis in human solid tumors?”.