Further methodological development of the Test Instrument for Profile of Physical Ability (TIPPA) designed for patients with long-term musculoskeletal pain

Abstract In a heterogeneous group of patients with long-term musculoskeletal pain (LMP), there is a need for a short test to assess physical ability. The Test Instrument for Profile of Physical Ability (TIPPA) includes observed physical ability and pain behaviour as well as the individual's self-assessment of his or her ability and experience of exertion. The relation between these four dimensions of the individual is made visible in a profile. The aim of this study was to investigate the inter-rater reliability of pain behaviour, to reconstruct the limits for the grades in the nine physical activities and to investigate the test–retest reliability of these reconstructed grades. The results showed that the percentual agreement between the two physiotherapists who observed LMP patients (n = 7) was 100% for seven of the activities and 86% for the two remaining activities. The reconstruction of the grading system was based on the results of healthy persons (n = 48) and LMP patients (n = 658) performing the nine physical activities. For test–retest of the reconstructed grading system in a patient group (n = 13), no disagreement was found between occasions but a systematic disagreement was found in one activity. This study confirms that the TIPPA instrument is reliable and the grading system discriminates between healthy persons and LMP patients.