Table 1.

Modified grading of qualitative evidence with best evidence synthesis for diagnostic accuracy and therapeutic interventions

Level I	Evidence obtained from multiple relevant high quality randomized controlled trials
	or
	Evidence obtained from multiple high quality diagnostic accuracy studies
Level II	Evidence obtained from at least one relevant high quality randomized controlled trial or multiple relevant moderate or low quality randomized controlled trials
	or
	Evidence obtained from at least one high quality diagnostic accuracy study or multiple moderate or low quality diagnostic accuracy studies
Level III	Evidence obtained from at least one relevant moderate or low quality randomized controlled trial study
	or
	Evidence obtained from at least one relevant high quality non-randomized trial or observational study with multiple moderate or low quality observational studies
	or
	Evidence obtained from at least one moderate quality diagnostic accuracy study in addition to low quality studies
Level IV	Evidence obtained from multiple moderate or low quality relevant observational studies
	or
	Evidence obtained from multiple relevant low quality diagnostic accuracy studies
Level V	Opinion or consensus of large group of clinicians and/or scientists.

Source: Manchikanti et al[82].