Prevalence of axial spondylarthritis in the United States: estimates from a cross-sectional survey

Arthritis Care Res (Hoboken). 2012 Jun;64(6):905-10. doi: 10.1002/acr.21621. Epub 2012 Jan 24.


Objective: The US national prevalence of spondylarthritis (SpA) was estimated for 2 published sets of classification criteria: the Amor criteria and the European Spondylarthropathy Study Group (ESSG) criteria. These 2 SpA criteria sets have been the most widely utilized in previous population-based studies of SpA.

Methods: The US SpA prevalence estimates were based on a representative sample of 5,013 US adults ages 20-69 years who were examined in the US National Health and Nutrition Examination Survey (NHANES) 2009-2010.

Results: The overall age-adjusted prevalence of definite and probable SpA by the Amor criteria was 0.9% (95% confidence interval [95% CI] 0.7-1.1%), corresponding to an estimated 1.7 million persons (95% CI 1.4-2.1 million persons). The age-adjusted prevalence of SpA by the ESSG criteria was 1.4% (95% CI 1.0-1.9%), corresponding to an estimated 2.7 million persons (95% CI 1.9-3.7 million persons). There were no statistically significant sex differences in SpA prevalence. The SpA prevalence among non-Hispanic white persons was 1.0% (95% CI 0.7-1.5%) by the Amor criteria and 1.5% (95% CI 1.0-2.3%) by the ESSG criteria. SpA prevalence could not be reliably estimated in other race/ethnicity subgroups due to sample size imitations.

Conclusion: The SpA prevalence estimates are in the range of SpA prevalence estimates reported elsewhere in population-based surveys and it is likely that SpA may affect up to 1% of US adults, a prevalence similar to that reported for rheumatoid arthritis. The current US SpA prevalence estimates may be lower than the true value because the NHANES 2009-2010 data collection did not capture a complete set of the elements specified in the 2 SpA criteria sets.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Axis, Cervical Vertebra
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nutrition Surveys
  • Prevalence
  • Retrospective Studies
  • Spondylarthritis / epidemiology*
  • Spondylarthritis / ethnology
  • United States / epidemiology
  • White People / ethnology