asas_axial_spa: ASAS Criteria for Axial Spondyloarthritis (SpA)

In cliot: Clinical Indices and Outcomes Tools

ASAS Criteria for Axial Spondyloarthritis (SpA)

Description

Applies the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial spondyloarthritis. These criteria are applicable to patients with back pain for >= 3 months and age of onset < 45 years. Classification is achieved through either the "Imaging Arm" (Sacroiliitis + >=1 SpA feature) or the "Clinical Arm" (HLA-B27 + >=2 other SpA features).

Usage

asas_axial_spa(back_pain_gt_3mo, age_onset_lt_45, sacroiliitis_imaging, hla_b27,
               inflammatory_bp, arthritis, enthesitis_heel, uveitis, dactylitis,
               psoriasis, crohns_colitis, good_nsaid_response, family_history_spa,
               elevated_crp_esr)

Arguments

back_pain_gt_3mo	Numeric (0 or 1). Back pain duration >= 3 months. (Entry Criterion).
age_onset_lt_45	Numeric (0 or 1). Age at onset of back pain < 45 years. (Entry Criterion).
sacroiliitis_imaging	Numeric (0 or 1). Active (acute) inflammation on MRI highly suggestive of sacroiliitis associated with SpA, OR definite radiographic sacroiliitis according to modified New York criteria.
hla_b27	Numeric (0 or 1). Positive HLA-B27 status.
inflammatory_bp	Numeric (0 or 1). History of inflammatory back pain.
arthritis	Numeric (0 or 1). Arthritis (past or present).
enthesitis_heel	Numeric (0 or 1). Enthesitis (heel).
uveitis	Numeric (0 or 1). Uveitis (past or present).
dactylitis	Numeric (0 or 1). Dactylitis (past or present).
psoriasis	Numeric (0 or 1). Psoriasis (past or present).
crohns_colitis	Numeric (0 or 1). Crohn's disease or ulcerative colitis (past or present).
good_nsaid_response	Numeric (0 or 1). Good response to NSAIDs (back pain relief within 24-48h).
family_history_spa	Numeric (0 or 1). Family history for SpA (in first- or second-degree relative).
elevated_crp_esr	Numeric (0 or 1). Elevated CRP or ESR (after exclusion of other causes).

Value

A list containing:

Classification	"Classified as Axial Spondyloarthritis", "Not Classified", or "Not Applicable".
Criteria_Arm_Met	Indicates if the patient met the "Imaging Arm", "Clinical Arm", or "Both".

References

Rudwaleit M, van der Heijde D, Landewé R, et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection. Ann Rheum Dis. 2009;68(6):777-783. doi:10.1136/ard.2009.108233

Examples

# Example 1: Imaging Arm
# Entry criteria met, Sacroiliitis present, Inflammatory BP present
asas_axial_spa(1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)

# Example 2: Clinical Arm
# Entry criteria met, No imaging findings, HLA-B27 Positive,
# Uveitis present, Family History present (2 clinical features)
asas_axial_spa(1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.