Concepts important to patients with psoriatic arthritis are not adequately covered by standard measures of functioning

Objective To explore whether the concepts important to patients with psoriatic arthritis (PsA) are covered by self-report instruments assessing functioning. Methods We conducted a qualitative focus group study with PsA patients about their problems in daily functioning. Focus groups were tape recorded and transcribed verbatim. The transcribed texts were divided into meaning units, and concepts contained in these meaning units were extracted. Self-report instruments assessing functioning in PsA were identified in a structured literature search. Using the International Classification of Functioning, Disability and Health (ICF) as a common frame of reference, we determined whether each concept identified in the focus groups was covered by each of the instruments. Results Thirty-one patients participated in 6 focus groups. The following 9 instruments were included in the present analysis: Arthritis Impact Measurement Scale Short Form; Bath Ankylosing Spondylitis Disease Activity Index; Disabilities of the Arm, Shoulder, and Hand Questionnaire; Dermatology Quality of Life Index; Dougados Functional Index; Health Assessment Questionnaire (HAQ); HAQ-S (HAQ adapted for spondylarthropathies); PsA-specific Quality of Life Instrument; and Short Form 36 Health Survey. Of the 54 concepts identified in 590 meaning units in the transcribed data, 19 concepts (35%) were not covered by any of the instruments. Of these, 11 concepts that were linked to the ICF component environmental factors were not covered by any of the instruments, whereas all concepts linked to the ICF component activities and participation were covered by at least 1 of the instruments (but no single instrument covered all concepts). Conclusion The impact of environmental factors, attitudes towards individuals with health problems, and loss of leisure time may represent important aspects addressing participation that are currently not covered in the instruments assessing functioning in PsA.