To estimate the current US inflammatory back pain (IBP) prevalence using four published case definitions.

Analysis of an IBP data collection instrument specifically designed for the 2009–10 National Health and Nutrition Examination Survey. Subjects were 5103 US adults ages 20–69 with complete data. IBP prevalence as determined by Calin et al criteria, European Spondylarthropathy Study Group (ESSG) criteria, and Berlin criteria 8a and 7b.

Age-adjusted US prevalence of IBP by Calin criteria was 5.0% (95% CI 4.2% to 5.8%). Prevalence of IBP was 5.6% (95% CI 4.7% to 6.5%) by ESSG criteria, and 5.8% (95% CI 5.2% to 6.4%) and 6.0% (95% CI 4.9% to 7.1%) by Berlin Criteria 8a and 7b, respectively. IBP prevalence did not differ significantly by age groups or between men and women. IBP prevalence was significantly lower among non-Hispanic black persons compared with non-Hispanic white persons for the Calin and ESSG IBP criteria. For the ESSG and Berlin 7b criteria, non-Hispanic white persons had significantly higher IBP prevalences compared with Mexican Americans.

IBP is associated with spondyloarthritis. Awareness of the prevalence of IBP may be useful for planning future epidemiological studies as well as development and validation of diagnostic and classification criteria for specific clinically defined diseases.