Table 3.

Physical Fatigability Bifactor Loadings and I-ECV Values

Item Content	General Factor	Health Challenges	Daily Living Challenges	Seating Challenges	Access Challenges	I-ECV
Sleep problems	0.377	0.725				0.213
Pain	0.730	0.218				0.918
Indigestion problems	0.385	0.906				0.153
Dehydration problems	0.560	0.092				0.974
Spasticity	0.419	0.284				0.685
Stress	0.323	0.458				0.332
Medication side-effects	0.420	0.126				0.917
Wheelchair transfer to and from bed	0.477		0.320			0.690
Wheelchair use around the home	0.700		0.496			0.666
Household chores, such as cleaning and tidying	0.551		0.830			0.306
Preparing and clearing away a meal	0.478		0.206			0.843
Eating a meal	0.555		0.278			0.799
Lack of peace and quiet	0.476		0.276			0.748
Inadequately adapted home	0.583		0.143			0.943
Inadequate medical care when at home	0.374		0.083			0.953
Inadequate non-medical care when at home	0.380		0.107			0.927
Concentrating for an hour or more (such as reading, writing, or holding a conversation)	0.604		0.108			0.969
Using a computer for an hour or more	0.566		0.024			0.998
Letter-writing, form filling or paying bills	0.678		0.038			0.997
Sitting in a wheelchair for an hour or more	0.512			0.672		0.367
Poor posture	0.615			0.244		0.864
Spending all day in your wheelchair	0.935			0.263		0.927
Pressure management (preventing pressure sores)	0.496			0.335		0.687
Posture management	0.745			0.078		0.989
Wheelchair use over a smooth surface	0.773				0.251	0.905
Wheelchair use over an uneven surface	0.811				0.126	0.976
Wheelchair transfer to and from car	0.608				0.063	0.989
Traveling in your vehicle for an hour or more	0.510				0.679	0.361
Using an adapted taxi	0.543				0.597	0.453
Using a bus	0.653				0.172	0.935
Using a train	0.621				0.199	0.907
Going to a doctor's appointment	0.968				0.210	0.955
Shopping, such as having access and reaching merchandise	0.962				0.167	0.970
Attending an event, such as cinema, theater, or a show	0.518				0.435	0.586
Visiting friends	0.582				0.555	0.524
Attending a sporting event	0.702				0.530	0.637
Taking a day trip away from home	0.643				0.570	0.560
Taking an overnight trip away from home	0.648				0.465	0.660
Taking a vacation away from home	0.495				0.462	0.534

Abbreviations: Physical Fatigue (PF); Item explained common variance (I-ECV)

Items stem was: During the past 4 weeks did you experience each of the following? If so, how much physical fatigue did each cause you?

Answer options: No fatigue (0); Mild fatigue (1); Moderate fatigue (2); Extreme fatigue (4).