Minimal Clinically Important Difference in Parkinson’s Disease as Assessed in Pivotal Trials of Pramipexole Extended Release

Table 4

The minimal clinically important difference and the substantial clinical difference in UPDRS scores in early PD and advanced PD.

Change	Pramipexole	Early PD (PGI-I data)			Advanced PD (PGI-I data)
		UPDRS II	UPDRS III	UPDRS II+III	UPDRS II	UPDRS III	UPDRS II+III	OFF time (hrs)
Minimal clinically important difference	Extended release	−1.8	−6.2	−8.0	−1.8	−5.2	−7.1	−1.0
	Immediate release	−2.0	−6.1	−8.1	−2.3	−6.5	−8.8	−1.3
Substantial clinical difference	Extended release	−3.0	−9.0	−12.1	−3.6	−8.2	−11.8	−1.5
	Immediate release	−3.2	−7.1	−10.3	−3.9	−8.9	−12.8	−2.2

PGI-I: Patient-rated Global Impression of Improvement.
(i) Minimal clinically important difference is defined as the mean change in the outcome measure in active treatment group subjects who rated themselves “a little better” on PGI-I minus the mean change in placebo-treated subjects who rated themselves as unchanged.
(ii) Substantial clinical difference is defined as the mean change in the outcome measure in active treatment group subjects who rated themselves “much better” on PGI-I minus the mean change in placebo-treated subjects who rated themselves as unchanged.