Classification criteria for spondyloarthropathies

Table 1 Inflammatory back pain criteria sets and mnemonic for assessment of spondyloarthritis international society criteria[11-13,17]

Calin’s criteria for IBP	Berlin criteria for IBP	ASAS IBP criteria mnemonic for criteria “iPAIN”
Age at onset < 40 yr	Morning stiffness of > 30 min duration	Insidious onset
Duration of back pain > 3 mo	Improvement in back pain with exercise but not with rest	Pain at night (with improvement upon getting up)
Insidious onset
Morning stiffness	Nocturnal awakening (second half of the night only)	Age at onset < 40 yr
Improvement with exercise	Alternating buttock pain	Improvement with exercise
		No improvement with rest
Requires the presence of four of five criteria	The sensitivity is 70% specificity 81% if two of the four criteria are fulfilled	The sensitivity is 77.0% and specificity 91.7% if at least four out of five criteria are fulfilled

IBP: Inflammatory back pain; ASAS: Assessment of spondyloarthritis international society; iPAIN: Inflammatory PAIN.