Interpretation of response categories in patient-reported rating scales: a controlled study among people with Parkinson's disease

Table 2 Sample characteristics

	PD (n = 51)	Controls (n = 36)	P-value ^e
Male gender, n (%)	36 (71)	14 (39)	0.008 ^f
Age, mean (SD)	66 (8.1)	66.2 (9.3)	0.889 ^g
Academic/professional degree, n (%)	26 (51)	19 (53)	0.889 ^f
Physical functioning, median (q1-q3) ^a	75 (50-90)	90 (80-95)	0.008 ^h
Mental health, median (q1-q3) ^a	76 (64-88)	84 (76-92)	0.068 ^h
PD duration (years), mean (SD)	9.8 (5.6)	-	-
Hoehn & Yahr ("on"), median (q1-q3; min-max) ^b,c	II (II-III; I-V)	-	-
Hoehn & Yahr ("off"), median (q1-q3; min-max) ^b,d	III (III-IV; I-V)	-	-
Motor fluctuations, n (%)	36 (71)	-	-
Dyskiesias, n (%)	25 (49)	-	-

^a According to the Physical Functioning and Mental Health scales of the SF-36. Possible score range, 0-100 (100 = better).
^b Range, I-V (I = mild unilateral disease; II = Bilateral disease without postural impairment; III = Bilateral disease with postural impairment, moderate disability; IV = Severe disability, still able to walk and stand unassisted; V = Confined to bed or wheelchair unless aided) [23].
^c As determined for the "on" phase, i.e. periods with good anti-parkinsonian drug response.
^d As determined for the "off" phase, i.e. periods with poor or no anti-parkinsonian drug response.
^e Adjusted for multiple testing using the Benjamini-Hochberg procedure [30].
^f Chi-square test.
^g Independent samples t-test.
^h Mann-Whitney U-test.
PD, Parkinson's disease; SD, standard deviation; q1-q3, 25^th and 75^th percentiles.

ISSN: 1477-7525