Calibration and validation of an item bank for measuring general physical function of patients in medical rehabilitation settings

Figures & data

Table 1 Sample characteristics

Characteristics	Values	Total sample (N =2337)
		n	%
Sex	Male	843	36.2
	Female	1484	63.8
	Missing (percentage of full sample)	10	0.4
Age (years)	18–44	488	20.9
	45–65	785	33.6
	≥66	1060	45.4
	Missing (percentage of full sample)	4	0.2
Impairment category	Stroke	515	24.2
	Brain dysfunction	121	5.7
	Neurologic condition	220	10.3
	Non-traumatic spinal cord dysfunction	55	2.6
	Traumatic spinal cord dysfunction	55	2.6
	Amputation	40	1.9
	Arthritis	117	5.5
	Pain syndrome	307	14.4
	Orthopedic conditions	395	18.6
	Cardiac pulmonary	103	4.8
	Congenital deformities	9	0.4
	Other disabling impairments	192	9.0
	Missing (percentage of full sample)	208	9.8
Acuity/onset (days)	0–21	515	22.5
	22–90	617	27.0
	≥91	1152	50.4
	Missing (percentage of full sample)	53	2.0
Severity index	Asymptomatic, no treatment needed at this time	7	0.5
	Symptoms well controlled with current therapy	235	16.5
	Symptoms controlled with difficulty, needs ongoing monitoring	743	52.1
	Symptoms poorly controlled, needs frequent adjustment in treatment	407	28.6
	Symptoms poorly controlled, history of re-hospitalization	33	2.3
	Missing (percentage of full sample)	912	39.0
Number of comorbidities	0	739	31.6
	1	840	35.9
	2	457	19.6
	≥3	301	12.9
	Missing (percentage of full sample)	0	0

Table 2 Item parameters for the general physical function scale

Item	Average location	a (discrimination)	b1 (threshold 1)	b2 (threshold 2)
Do you limit the kind of work or other regular daily activities as a result of your physical health?*	2.06	1.05	2.06	N/A
How much does your health limit completing your toileting?	−0.68	2.22	−1.23	−0.13
How much does your health limit getting in and out of bed?	−0.42	2.31	−0.97	0.13
How much does your health limit walking around a room?	−0.41	2.32	−0.97	0.14
How much does your health limit getting in and out of a chair?	−0.32	2.88	−0.88	0.23
How much does your health limit bathing or dressing?	−0.23	2.16	−0.78	0.32
How much does your health limit walking one block?	0.29	2.59	−0.26	0.84
How much does your health limit climbing one flight of stairs?	0.45	2.82	−0.1	1
How much does your health limit attending social events?	0.58	1.77	0.03	1.14
How much does your health limit walking several blocks?	0.74	2.77	0.19	1.3
How much does your health limit going on vacation?	0.75	1.7	0.2	1.31
How much does your health limit bending, kneeling, or stooping?	0.78	2.54	0.22	1.33
How much does your health limit lifting or carrying items like groceries?	0.89	2.22	0.34	1.44
How much does your health limit moderate activities like moving a table or pushing a vacuum cleaner?	1.00	2.30	0.45	1.55
How much does your health limit climbing several flights of stairs?	1.04	2.42	0.49	1.59
How much does your health limit walking more than a mile?	1.47	2.06	0.92	2.02
How much does your health limit participating in recreation?	1.82	1.46	1.27	2.37
How much does your health limit vigorous activities like running, lifting heavy objects, sports?	2.24	1.56	1.69	2.8

Notes:

* Response categories for this item were “yes” and “no”. For all other items, responses were: “yes, limited a lot”, “yes, limited a little”, and “no, not limited at all”.

Table 3 Known-groups validity results

Analysis of variances	Groups	Sample (N=2337)
		Patients (n)	Mean	SD	p-value (Omnibus F test)	F value
General physical function scores by age (years)	18–44	488	47.8	21.0	0.000	52.1
	45–65	785	40.6	18.4
	≥66	1060	36.9	19.6
General physical function scores by severity index	Symptoms well controlled	235	46.6	19.9	0.000	16.6
	Symptoms controlled with difficulty	743	41.4	20.6
	Symptoms poorly controlled (both poorly controlled categories combined)	440	37.4	19.1
General physical function scores by number of comorbidities	0	739	45.1	20.6	0.000	31.7
	1	840	40.9	20.0
	3.2	457	36.6	18.2
	≥3	301	33.6	17.6