Ires Ghielen

26 Chapter 2 Results Of the original sample of 382 PD patients, 75 patients met exclusion criteria (MMSE < 24). An additional 13 patients were excluded from the analyses for not meeting our standards of acceptability of missing values on the BAI. This resulted in a total sample size of 294 patients. Due to missing data on the BDI, UPDRS-III and/or SCOPA- AUT, 3 to 18 additional patients were excluded pair-wise during statistical analyses. The majority of patients was male. Mean age was 64.5 years. Patients had a mean UPDRS-III score of 25.8 and a median Hoehn and Yahr stage of 2. Demographic and clinical characteristics of the sample are given in Table 1. Table 1. Demographic and clinical characteristics of subjects ( n = 294) Mean SD Range % Female 39.5 Age 64.5 10.3 27-89 Disease duration (yr) 5.1 5.6 0-40 MMSE score 28.0 1.7 24-30 BDI score 11.4 8.0 0-36 SCOPA-AUT score 35 10.0 0-64 UPDRS-III score 25.8 12.3 2-58 Hoehn & Yahr stage 2 (median) 1-5 % Use dopaminergic medication 48.6 Occurrence and symptom dimensions of anxiety in PD The mean score on the BAI was 14.2 (SD 9.8, range 0-50). Forty-five percent of patients in our sample had a BAI score of 12 or more, which is considered to be a clinically relevant level of anxiety [14]. The Eigenvalue >1 criterium suggested that five factors should be extracted. This was confirmed by an inspection of the scree plot (see Figure S1 in the supplementary material). Items 3 ‘wobbliness in legs’, 7 ‘heart pounding/racing’ and 18 ‘indigestion’ had a loading of less than 0.4 on all factors and were therefore excluded from the factor solution. The five obtained factors were interpreted as anxiety , thermoregulation, hypotension, hyperventilation and trembling . The factor solution explained 62.7% of variance. Figure 1 demonstrates the distribution of the BAI items over the five factors, with corresponding factor loadings.