Progression of Voice and Speech Impairment in the Course of Parkinson's Disease: A Longitudinal Study

Table 1

Participants’ characteristics and results.

	PD group (𝑛=80; 48 male)						Control group (𝑛=60; 30 male)
	𝑡0		𝑡1				𝑡0		𝑡1
					𝑡0 versus 𝑡1						𝑡0 versus 𝑡1
	Mean	S.D.	Mean	S.D.			Mean	S.D.	Mean	S.D.
Age	66.28	8.11					66.87	7.10
Disease duration  (months)	73.10	55.54	105.63	57.15
𝑡0−𝑡1  (months)			32.53	19.53					25.39	7.08
Hoehn&Yahr𝑡0	2.16	0.58
UPDRS III	20.16	10.96	19.58	8.29	n.s.
UPDRS speech	1.00	0.68	1.39	0.86	𝑃<0.0001
Perceptual rating					𝑡0 versus 𝑡1	C 𝑑
Intelligibility score	0.41	0.57	0.96	0.92	𝑃<0.0001	0.72	0.08	0.28	0.13	0.34	n.s.
Perceptual score	2.59	1.82	4.06	2.33	𝑃=0.0001	0.71	0.60	0.79	0.70	0.77	n.s.
Voice	0.86	0.67	1.36	0.70	𝑃<0.0001	0.73	0.30	0.46	0.38	0.49	n.s.
Articulation	0.38	0.54	0.71	0.87	𝑃<0.0001	0.46	0.07	0.25	0.13	0.34	n.s.
Fluency	0.63	0.64	0.96	0.95	𝑃<0.0001	0.41	0.02	0.13	0.03	0.18	n.s.
Prosody	0.73	0.64	1.01	0.57	𝑃<0.0001	0.46	0.22	0.42	0.15	0.36	n.s.
Acoustic analysis					𝑡0 versus 𝑡1	C 𝑑
Jitter	1.263	1.038	1.358	0.956	n.s.	—	1.186	0.777	1.205	0.893	n.s.
Shimmer	6.548	3.914	11.490	7.024	𝑃<0.0001	0.87	5.222	2.114	5.209	2.763	n.s.
nh_ratio	0.051	0.062	0.103	0.105	𝑃<0.0001	0.61	0.038	0.029	0.041	0.031	n.s.
Mean 𝐹0—male	133.33	24.20	131.14	23.88	n.s.	—	124.31	12.71	123.58	13.04	n.s.
Mean 𝐹0—female	186.34	25.04	183.93	31.22	n.s.	—	186.29	15.19	188.62	17.21	n.s.
𝐹0 SD—male	16.90	5.24	15.94	5.93	n.s.	—	19.27	6.40	19.02	6.59	n.s.
𝐹0 SD—female	23.00	6.55	22.21	0.30	n.s.	—	34.11	8.06	33.91	8.55	n.s.
NSR	5.36	0.75	5.19	0.68	𝑃=0.0003	0.24	5.18	0.48	5.16	0.50	n.s.
PR%	14.65	5.35	15.30	7.05	n.s.	—	17.19	4.38	17.84	4.33	n.s.
Pinw%	21.24	11.15	18.46	10.55	𝑃=0.016	0.26	29.96	9.98	28.62	10.21	n.s.
VAI—male	0.740	0.081	0.677	0.069	𝑃<0.0001	0.84	0.767	0.058	0.759	0.063	n.s.
VAI—female	0.837	0.066	0.792	0.052	𝑃<0.0001	0.76	0.874	0.062	0.861	0.069	n.s.

n.s.: not significant; S.D.: standard deviation; C 𝑑: Cohen’s 𝑑/effect size.
𝑡₀ versus 𝑡₁: comparison between baseline and follow-up/paired 𝑡-test.