Table 3.

Cognition.

Predictors						Outcomes
	Variables	Animal fluency				Delayed 90″ recall
		FΔ	R2 Δ	Beta	Sig.	F Δ	R2 Δ	Beta	Sig.
Final model		19.498	0.162		<0.001	11.534	0.103		<0.001
Demographics		85.575	0.117		<0.001	47.562	0.069		<0.001
	Age			−0.252	<0.001			−0.162	<0.001
	Sex			0.002	0.927			0.149	<0.001
	Living			−0.021	0.340			−0.009	0.690
PD severity		17.693	0.024		<0.001	12.180	0.017		<0.001
Model	Resting tremor			−0.05	0.018			0.024	0.266
	H&Y stage			−0.115	<0.001			−0.081	0.001
	Disease duration			−0.008	0.733			−0.057	0.017
Medication		6.631	0.015		<0.001	4.653	0.011		<0.001
Model	Levodopa			−0.067	0.004			−0.047	0.048
	Dopamine agonist			0.021	0.332			0.017	0.462
	Anti depressant			−0.017	0.434			−0.008	0.731
	Stimulant			0.012	0.562			0.025	0.245
	Cognitive enhancer			−0.093	<0.001			−0.092	<0.001
Comorbidity		1.869	0.007		0.061	1.503	0.006		0.151
Model	Heart/circulation			−0.002	0.918			−0.050	0.030
	Respiratory			−0.017	0.430			0.025	0.260
	Diabetes			−0.041	0.061			−0.018	0.417
	Neurological			−0.035	0.098			0.000	0.992
	Cancer			−0.035	0.100			0.001	0.979
	Arthritis			−0.032	0.150			0.036	0.120
	BMI squared			−0.009	0.677			−0.018	0.414
	BMI			0.006	0.802			−0.031	0.176

Results from separate hierarchical regression analyses examining the relationship between comorbidities and cognitive tasks (animal fluency and delayed memory recall). Variables pertaining to demographics, PD severity and medication status were statistically controlled for in preceding blocks of predictors.