Table 4 Key outcome measures in common use for assessment of psoriatic arthritis

Disease activity

Composite measures

   ACR 20, 50, 70 response

Percentage improvement in tender and swollen joint counts in addition to improvement in three out of five measures: physician's and patient's assessment of disease activity, patient's assessment of pain, acute phase reactant, and functional questionnaire

[116]

   PsARC

Improvement by >1 point in both physician's and patient's assessment of disease activity in addition to >30% reduction in tender and swollen joint counts

[117]

Skin disease

   PASI 50, 75

Percentage improvement in severity and extent of skin involvement

[118]

Minimal disease activity

Having five of the following seven criteria: tender joint count <1; swollen joint count <1; PASI <1 or body surface area <3; patient pain VAS <15; patient global disease activity VAS <20; health assessment questionnaire <0.5; and tender entheseal points <1

[119]

Radiograph scoring

Sharp score

Joint erosion + joint narrowing scores

[120]