Table 3.

Predictors of mortality in ET cases (Univariate Cox proportional hazards models)

Variable	Beta	HR	95% CI	Significance
Age (years)	0.16	1.18	1.12–1.23	p < 0.001
Female	0.003	1.00	0.57–1.76	p = 0.99
White race	−3.03	0.05	0.00–570.47	p = 0.53
Education (years)	−0.11	0.89	0.80–1.00	p = 0.04
Number of prescription medications	0.09	1.09	1.04–1.15	p = 0.001
Current cigarette smoker	−0.79	0.46	0.06–3.30	p = 0.46
Age of tremor onset (years)	0.01	1.01	1.00–1.03	p = 0.06
Tremor duration (years)	0.01	1.01	0.98–1.02	p = 0.15
Total tremor score	0.07	1.07	1.01–1.13	p = 0.02
MoCA score	−0.20	0.82	0.76–0.87	p < 0.001
MMSE score	−0.28	0.75	0.70–0.81	p < 0.001
Cognitive diagnosis
Normal (reference group)
Non-amnestic MCI	0.19	1.21	0.29–5.11	p = 0.79
Amnestic MCI	1.31	3.71	1.83–7.52	p < 0.001
Dementia	2.03	7.61	3.89–14.89	p < 0.001
CDR
0 (reference group)
0.5	0.70	2.00	1.05–3.83	p = 0.04
1	1.72	5.59	2.59–12.08	p < 0.001
2	3.71	40.77	12.46–133.45	p < 0.001
Overall	1.80	6.02	3.55–10.22	p < 0.001
Cognitive domain
Memory	−0.77	0.46	0.36–0.61	p < 0.001
Executive function	−0.88	0.41	0.29–0.59	p < 0.001
Attention	−0.56	0.57	0.38–0.85	p = 0.006
Visuospatial abilities	−0.37	0.69	0.47–1.01	p = 0.06
Language	−0.51	0.60	0.39–0.92	p = 0.02
GDS	0.03	1.03	0.98–1.08	p = 0.26
Number of falls reported in the past year	0.08	1.08	1.02–1.15	p = 0.02
Number of tandem missteps	0.31	1.36	1.22–1.52	p < 0.001
PASE score	−0.02	0.99	0.98–0.99	p < 0.001
PSQI item: average hours of sleep	0.002	1.00	0.77–1.31	p = 0.99
PSQI item: sleep quality	−0.03	0.97	0.62–1.51	p = 0.89

Bolded values are statistically significant (p < 0.05).

CDR, Clinical Dementia Rating; CI, confidence interval; ET, essential tremor; GDS, Geriatric Depression Scale; HR, hazard ratio; MCI, mild cognitive impairment; MoCA, Montreal Cognitive Assessment; MMSE; Mini-Mental State Exam; ESS, Epworth Sleepiness Scale; PASE, Physical Activity Scale for the Elderly.