A Narrative Review on the Pathophysiology and Management for Radiation Cystitis

Table 5

Levels of evidence [27].

Level of evidence	Type of evidence
1a	Systematic review (with homogeneity) of randomised control trials
1b	Individual randomised control trials (with narrow confidence intervals)
1c	All or none randomised control trials
2a	Systematic review (with homogeneity) of cohort studies
2b	Individual cohort study or low quality randomised control trials
2c	Outcomes research
3a	Systematic review (with homogeneity) of case-control studies
3b	Individual case-control study
4	Case series (and poor quality cohort and case-control studies)
5	Expert opinion