Table 1 Key outcome measures in common use for assessment of axial disease in ankylosing spondylitis

Disease activity

BASDAI

Self-administered VAS questionnaire: fatigue, axial pain, peripheral joint pain, tenderness, stiffness

[99]

ASAS 20, 40, 70

Percentage improvement in three out of four domains: patient global, pain, function and inflammation

[100, 101]

ASAS 5/6

> 20% improvement in all four ASAS domains + one of CRP or metrology

[101]

Partial remission

< 20% activity in all four ASAS domains

[100]

ASDAS

Includes CRP

[102]

Physical function

BASFI

Self-administered VAS questionnaire: 10 questions about day-to-day tasks

[103]

Dougados index

Self-administered VAS questionnaire: 20 questions about day-to-day tasks

[104]

HAQ-S

Self-administered questionnaire scoring difficulty of 25 day-to-day tasks

[105]

Metrology

BASMI

Five clinical measurements: cervical rotation, tragus to wall distance, lateral lumbar flexion, modified Schober's, intermalleolar distance

[106]

EDASMI

Four clinical measurements: cervical rotation, lateral lumbar flexion, chest expansion, and internal rotation of the hip

[107]

Spine X-ray score

mSASSS

Disease of anterior vertebral corners on a lateral cervical and lumbar radiograph

[108]

Spine MRI score

Berlin Score

Vertebral junction disease by quantifying bone marrow oedema

[109]

ASspiMRI-a

Vertebral junction disease by quantifying bone marrow oedema and erosions

[110]

SPARCC Index

Vertebral junction disease by quantifying bone marrow oedema

[111]

Work

AS-WIS

A simple 20-item questionnaire to measure work instability in AS

[112]

WPAI-SHP

Quantitative measure of reduced productivity, both at work and during nonwork activities

[113]

Questionnaire

Health-related quality of life

ASQoL

Addresses symptoms, function and disease-related concern

[114]

SF-36

Physical and mental health assessment

[115]