Aim: The aim of this paper was to develop and evaluate a patient-specific index for physiotherapy in Parkinson's disease (PSI-PD).
Methods: In the PSI-PD, patients 1) select problematic activities out of a predefined list, with one self-report item; 2) rank selected items in order of importance; and 3) rate severity for each ranked item. To examine test-retest reliability, a cohort of patients was asked to complete the PSI-PD twice. Afterwards, validity was evaluated using a telephone interview.
Results: The PSI-PD was completed twice by 81 patients. Test-retest agreement for the selection of activity limitations was 73% to 94%. Items ranked by patients were categorized into domains, of which gait, transfers and dexterity were rated most frequently (41%-70%). Test-retest agreement for ranked domains ranged from 74% to 82%. Interviews confirmed that the PSI-PD reliably identified problem areas.
Conclusions: The PSI-PD is a relevant, reliable and valid instrument to identify limitations in everyday activities that are important for both PD patients and physiotherapists.