Table 4. PROMIS applied cognition - general concerns item set. Reliability statistics Alpha, Omega Total and explained common variance (ECV) for the total sample and demographic subgroups (“Psych” R package).

	Cronbach's Alpha	Ordinal Alpha	McDonald's Omega	ECV
Total Sample	0.975	0.985	0.985	85.113
Random Second Half of the Sample	0.974	0.985	0.985	84.581
Age 21 to 49 years	0.977	0.986	0.986	85.942
Age 50 to 64 years	0.976	0.986	0.986	85.612
Age 65 to 84 years	0.971	0.983	0.983	83.145
Male	0.974	0.986	0.986	84.673
Female	0.975	0.985	0.985	85.050
Non-Hispanic White	0.977	0.987	0.987	86.176
Non-Hispanic Black	0.975	0.985	0.985	84.891
Hispanic	0.974	0.984	0.984	84.563
Non-Hispanic Asian/Pacific Islander	0.971	0.983	0.984	83.346
Less Than High School	0.972	0.982	0.983	83.781
High School Degree	0.974	0.984	0.985	84.707
Some College	0.977	0.987	0.987	86.350
College Graduate	0.973	0.985	0.985	84.399
Graduate Degree	0.974	0.986	0.986	84.893
Hispanics Interviewed in English	0.976	0.986	0.986	85.799
Hispanics Interviewed in Spanish	0.967	0.979	0.980	81.174