Cs. Palmer et al., Patient preferences and utilities for 'off-time' outcomes in the treatmentof Parkinson's disease, QUAL LIFE R, 9(7), 2000, pp. 819-827
The purpose of this study was to derive patient preferences and utilities f
or outcomes associated with treatment of motor fluctuations, or 'off-time',
for patients with Parkinson's disease (PD). Visual analog scale (VAS) and
standard gamble (SG) approaches were used with 60 patients to determine pat
ient preferences and utilities for 10 health state descriptions. Health sta
te descriptions were categorized according to two factors: disease severity
, and proportion of the day with 'off-time'. There were two representative
levels of disease severity, based on Hoehn and Yahr stages 1.5 and 2.5: uni
lateral disease with no postural instability, and bilateral disease with so
me postural instability. These severity levels were combined with five leve
ls of 'off-time' per day ranging from none to > 75% of the day. Patients' m
ean preference or utility for their own current health ranged from 0.65 +/-
0.20 (VAS) to 0.74 +/- 0.22 (SG). Patients assigned the lowest mean values
to the health state description for Hoehn and Yahr stage 2.5 with 'off-tim
e' for > 75% of the day (VAS: 0.17 +/- 0.17; SG: 0.49 +/- 0.27). The highes
t mean values were assigned to Hoehn and Yahr stage 1.5 with no 'off-time'
(VAS: 0.83 +/- 0.17; SG: 0.85 +/- 0.18). The results of this study indicate
d patients with PD would likely seek treatment that would minimize the amou
nt of 'off-time' experienced per day, and that patients were relatively ris
k averse.