Measuring health-related quality of life in patients with progressive supranuclear palsy.

The development of psychometrically sound health-related quality of life (Hr-QoL) instruments has made it possible to assess subjectively experienced Hr-QoL quantitatively, and to incorporate Hr-QoL as a measure in medical research and clinical trials. Hr-QoL in patients with progressive supranuclear palsy (PSP) has been measured using generic (not disease-specific) instruments, or Parkinson's disease-specific scales. We give an overview of the development of a disease-specific Hr-QoL instrument for patients with PSP. Based on interviews with 27 patients with PSP a preliminary Hr-QoL instrument was developed and administered to over 300 people with PSP in the UK and US. Following psychometric analysis a rating scale with a physical and a mental subscale emerged. In this patient sample, both subscales satisfied criteria for scaling assumptions, acceptability, reliability and validity (correlations with other measures consistent with a priori hypotheses). The psychometric properties of this questionnaire are undergoing further evaluation.