If good outcome is defined as the ability to perform outdoor activities mRs 0-1 should be chosen. If complex ADL are considered as good outcome mRs 0-2 is the outcome measure of choice. Independent of which outcome measure is chosen, the treatment effect in clinical trials must be large before good outcome is achieved. Therefore, it is likely that clinically important treatment effects can be missed in clinical trials with both these mRs endpoints.

Our findings are consistent with the theory of reduced dopamine D(2) receptor (D2R) availability in dystonia, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out.

Objective: The aim of this study was to examine the clinimetric properties of the AMC Linear Disability Score (ALDS), a new generic disability measure based on Item Response Theory, in patients with newly diagnosed Parkinson disease (PD). Methods:A sample of 132 patients with PD was evaluated using the Hoehn and Yahr (H&Y), the Unified PD Rating Scale motor examination, the Schwab and England scale (S&E), the Short Form-36, the PD Quality of Life Questionnaire, and the ALDS. Results:The internal consistency reliability of the ALDS was good (␣ ϭ 0.95) with 55 items extending the sufficient item-total correlation criterion (r Ͼ 0.20). The ALDS was correlated with other disability measures (r ϭ 0.50 to 0.63) and decreasingly associated with measures reflecting impairments (r ϭ 0.36 to 0.37) and mental health (r ϭ 0.23 to Ϫ0.01). With regard to knowgroup validity, the ALDS indicated that patients with more severe PD (H&Y stage 3) were more disabled than patients with mild (H&Y stage 1) or moderate PD (H&Y stage 2) (p Ͻ 0.0001). The ALDS discriminated between more or less severe extrapyramidal symptoms (p ϭ 0.001) and patients with postural instability showed lower ALDS scores compared to patients without postural instability (p ϭ Ͻ 0.0001). Compared to the S&E (score 100% ϭ 19%), the ALDS showed less of a ceiling effect (5%). Conclusion:The AMC Linear Disability Score is a flexible, feasible, and clinimetrically promising instrument to assess the level of disability in patients with newly diagnosed Parkinson disease.

Background: Currently, there is a lot of interest in the flexible framework offered by item banks for measuring patient relevant outcomes. However, there are few item banks, which have been developed to quantify functional status, as expressed by the ability to perform activities of daily life. This paper examines the measurement properties of the Academic Medical Center linear disability score item bank in a mixed population.