Psychometric validation of the revised SCOPA-Diary Card: expanding the measurement of non-motor symptoms in parkinson's disease

Table 4 Convergent/Discriminant and Known-Groups Validity

	Convergent/Discriminant Validity (Spearman Correlation Coefficients)				Known-Groups Validity Mean (SD)
	HRQOL Measures				Baseline Off-Time		Disease Duration
Revised SCOPA-DC Subscale	PDQ8-SI	WOQ-9 Percentage of Symptoms	SF-12 PCS	SF-12 MCS	Absence of off-time	Presence of off-time	Up to 5 years	More than 5 years
Mobility	0.60^†	0.45^†	-0.54^†	-0.47^†	21.7 (17.3)¹	28.3 (21.7)	24.9 (21.1)³	30.4 (21.1)
Physical Functioning	0.58^†	0.56^†	-0.46^†	-0.60^†	16.0 (17.6)¹	21.0 (15.5)	19.3 (15.6)³	20.5 (14.7)
Psychological Functioning	0.62^†	0.48^†	-0.39^†	-0.58^†	9.2 (20.7)²	15.9 (17.8)	12.4 (17.4)³	14.9 (15.8)

PDQ8-SI = Parkinson's Disease Questionnaire-8 Summary Index; WOQ-9 = Wearing-Off Questionnaire-9; SF-12 = Short Form-12 Health Survey; PCS = Physical Component Summary; MCS = Mental Component Summary; SD = Standard deviation; SCOPA-DC = Scales for Outcomes of Parkinson's disease Diary Card; HRQOL = Health-Related Quality of Life.
† = p < 0.001.
^1. Not statistically significantly different from mean score of fluctuators (p > 0.05).
^2. Statistically significantly different from mean score of fluctuators (p = 0.023).
^3. Not statistically significantly different from mean score of > 5 years (p > 0.05).

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