Table 1.

Final IRT Model for the 18 Frailty Markers

Item Description	Percent Endorsement of Item (N)	Difficulty (Location)	Standard Error	Discrimination (Slope)	Standard Error
PH1: Poor general health status	15.88 (448)	1.55	0.08	1.45	0.07
PH2: Worsening physical health	36.2 (1024)	0.65	0.06	1.09	0.05
PH4: Physical disability work status	10.6 (301)	2.25	0.08	1.15	0.13
PH5: Muscle weakness	16.7 (473)	1.91	0.07	0.99	0.11
PH7: Poor physical Quality of Life	47.9 (1354)	0.07	0.19	3.60	0.03
FFL4: Exhibit low energy	17.2 (485)	1.35	0.10	1.70	0.06
FFL6: Exhibit slow physical activities	33.6 (950)	0.48	0.23	3.96	0.03
FFL8: Worsening disability activities	6.9 (194)	1.74	0.21	2.82	0.06
FFL9: Limited in moderate ADLs§	58.8 (1663)	−0.25	0.17	3.23	0.03
FFL10: Limited ability in kind of work due to PH§	11.8 (335)	1.30	0.26	3.64	0.04
FFL11: Limited ability to work due to EP§	30.2 (855)	0.74	0.08	1.68	0.04
FFL12: Accomplish less due to PH/EP§	49.0 (1386)	0.04	0.29	4.78	0.03
FFL14: Limited climbing flights of stairs	54.6 (1543)	−0.14	0.10	2.01	0.03
MH1: Felt downhearted and blue	25.2 (712)	1.07	0.07	1.36	0.05
MH3: Felt calm and peaceful	32.5 (920)	0.73	0.07	1.34	0.05
MH4: Worsening emotional health	22.7 (641)	1.38	0.07	1.08	0.08
MH7: Poor mental quality of life	13.3 (377)	1.36	0.15	2.43	0.05
SASS4: Limited social activities	25.1 (709)	0.84	0.12	2.36	0.04
		Mean=0.95 (SD=0.72)		Mean=2.26 (SD=1.16)

^§ADL =Barthel Activities of Daily Living, PH = Physical Health and EP = Emotional Problem.