The factor structure of the SF-36 in Parkinson's disease.

RATIONALE, AIMS AND OBJECTIVES: The concept of quality of life (QoL) has emerged as an important psychological dimension in individuals experiencing Parkinson's disease (PD). The current study sought to determine the factor structure of the Medical Outcomes Study Short-Form 36 (SF-36) version 2 in patients with PD in order to evaluate how this measure might best be used to assess QoL in this clinical population.

METHOD

Confirmatory factor analyses were conducted on self-report SF-36 data from 339 individuals diagnosed with PD. Six structural models of the SF-36 were evaluated against the participants' data.

RESULTS

The underlying factor structure of the SF-36 in PD was observed to be inconsistent with the assumed measurement model of SF-36 but consistent with contemporary theoretical models of the instrument.

CONCLUSIONS

The use of the SF-36 in individuals with PD can be recommended when eight subscales are used and reported. Evidence to support the use of the instrument as a two-subscale measure of physical health and mental health components was not found.