Table 2.

Differences in scores on the Movement Disorder Society Unified Parkinson's Disease Rating Scale based on Hoehn and Yahr stage

MDS‐UPDRS	HY stage 1	HY stage 2	HY stage 3	HY stage 4	HY stage 5
Part I
No. of patients	343	1617	754	304	89
Mean ± SD	7.5 ± 4.6	10.4 ± 5.9***	14.4 ± 6.7***	18.9 ± 7.8***	22.8 ± 9.3***
Range	0–26	0–35	0–40	1–39	2–41
Part II
No. of patients	343	1613	754	303	88
Mean ± SD	6.5 ± 4.8	11.2 ± 6.6***	17.5 ± 7.4***	27.3 ± 8.8***	37.1 ± 8.3***
Range	0–25	0–44	1–45	1–49	10–52
Part III on
No. of patients	226	1080	522	196	55
Mean ± SD	14.4 ± 7.8	28.8 ± 12.3***	40.5 ± 14.2***	58.0 ± 16.2***	72.2 ± 16.3***
Range	2–44	4–71	8–95	21–106	38–118
Part III off
No. of patients	111	508	227	105	29
Mean ± SD	14.4 ± 7.0	29.4 ± 12.0***	42.7 ± 15.6***	61.1 ± 16.6***	73.7 ± 17.0***
Range	0–39	2–83	4–94	13–97	47–109
Part IV
No. of patients	342	1616	756	305	89
Mean ± SD	0.8 ± 2.0	2.4 ± 3.2***	4.8 ± 4.4***	7.6 ± 5.5***	8.4 ± 6.4*
Range	0–15	0–16	0–21	0–21	0–22

MDS‐UPDRS, Movement Disorder Society Unified Parkinson's Disease Rating Scale; HY, Hoehn and Yahr scale; SD, standard deviation.

*P < 0.05, ***P < 0.001 relating to differences between MDS‐UPDRS subscores in each consecutive HY stage.