Figure 1.
Dimensional scores of the PPS according to disease severity.
Dimensional sub scores are expressed as percentage of the maximum possible score in the dimension (as indicated in Table 1, far left column). Comparisons (Student's t tests) were made between the two sub-groups defined by the extreme values of the Clinician Global Impression of disease severity (CGI-ds) in the overall study population. CGI Borderline/Mild illness (score 1–2) n = 93, dotted line; CGI Severe/extremely severe illness (score 5–6) n = 142, solid line. ns: not significant at p<0.003 with Bonferroni correction.
Table 1.
NNIPPS-PPS scores at entry by diagnosis - Internal consistency and inter-rater reliability.
Figure 2.
Dimensional profiles of PSP and MSA at entry.
Overall profiles of Parkinson Plus Scale dimensional sub scores at entry for Progressive Supranuclear Palsy (PSP) and Multiple System Atrophy (MSA). Dimensional sub scores are expressed as percentage of the total score to evaluate relative contribution of each dimension to overall severity score. Comparisons (Student's t tests) were made between the two strata. PSP n = 362, dotted line; MSA n = 398, solid line. Left: sub scores unrelated to strata inclusion/exclusion criteria- three comparisons reached significance level at p<0.003: Limb bradykinesia, Rigidity and Myoclonia cumulating to 3.4% overall difference in contribution to total score. Right: sub scores related to strata inclusion/exclusion criteria- all differences are significant at p<0.003 with 28.2% overall difference in contribution to total score. Contributions of dimensions related to inclusion criteria amount for 27.6% and 17.3% for PSP and MSA respectively; Contributions of dimensions related to exclusion criteria amount for 4.9% and 11.8% in PSP and MSA respectively.
Figure 3.
Predictive validity: 3-year survival according to NNIPPS-PPS total score at entry.
Kaplan-Meier plot of the NNIPPS population broken down by quartiles of the NNIPPS-PPS total score at entry (grouping from lowest to highest severity: Group 1 score [0–65], Group 2 score [66–86], group 3 score [87–109], Group 4 score [110–182]. Log-rank analysis showed a highly significant difference (p<0.0001) between the four score groups with an inversely and linearly ordered survival according to score demonstrating an excellent predictive value of the NNIPPS-PPS.
Table 2.
Predictive validity of the NNIPPS-PPS total and dimensional scores on survival.
Table 3.
Patients Characteristics - Inter-rater reliability study.
Figure 4.
Profiles of PSP and MSA rates of change in dimensional sub scores.
Left figure: Slopes of change in dimensional sub scores (excluding Cerebellar and Orthostatic sub scores) were expressed as percentage of the maximum possible score in the dimension. Progressive Supranuclear Palsy (PSP), n = 362, dotted line; Multiple System Atrophy (MSA), n = 398, solid line. PSP patients showed higher rates of progression in all but two sub scores (Myoclonia and Tremor) compared to MSA patients. Right figure: For each strata, slopes of change in dimensional sub scores were expressed as percentage of the total score slope of change (excluding Cerebellar and Orthostatic sub scores) to evaluate relative contribution of each dimension to overall severity progression rate. PSP n = 362, dotted line; MSA n = 398, solid line. PSP and MSA showed similar profiles for severity progression with a 15.3% cumulative difference in contribution of dimensions to overall slope, including dimensions related to inclusion/exclusion criteria (Oculomotor, Mental, Urinary, and Tremor). In both diseases, the Akineto-Rigid and Bulbar syndromes were those contributing most to overall severity progression (71.6% and 72.2% for PSP and MSA respectively).
Table 4.
Responsiveness - slopes of change (mean ± SD) of the NNIPPS-PPS scores by Strata.
Table 5.
Sample size estimates (per group) using change in slope of clinical scales.