Table 1 Studies using IRT to establish hierarchy of decline in ADL-IADL Scales

Spector & Fleishman, 1998 (LH) [65]

National Long-Term Care Survey ADL & IADLs

Rasch-model

15 ADL- IADL

(1 item removed)

2(disabled vs. not disabled) #

Representative sample of disabled in the community *, Age 65 +, M = 79; n = 2,977

PS Reliability: .88

Haley et al., 2002 [66]

Late-Life FDI(function component)

Rasch-Rating Scale

27 ADL & IADL

(5 items misfit)

5 (assessing difficulty)

Community-dwelling, Age 60-98, M 75.9, SD 8.5; n = 150,

77% female

IS Index: 10.1

Sheehan et al., 2002

[64]

NHEFS disability questionnaire

Rasch-Partial Credit

24 ADL-IADL

(1 item misfit)

4 (assessing difficulty)

Noninstitutionalized general population of older Americans, Age 57-86, M = 62, n = 2,310

PS Index: 2.72

PS Reliability: .88

Jette et al, 2002 [67]

Late-Life FDI(disability component)

Rasch-Rating Scale

12 IADL

(4 items misfit)

5 (assessing frequency)

Community-dwelling, Age 60-98, M 75.9, SD 8.5; n = 150

IS Index: 9.39

Fortinsky et al., 2003 (LH) [14]

Outcome and Assessment Information Set

Rasch-Partial Credit

15 ADL-IADL

(zero items misfit)

3 to 6 (able to unable)

Community-dwelling, Medicare-eligible, with recent history of home care services, 1/3 of

Not reported

Dubuc et al., 2004 [62]

Physical Functioning Scale, PF -10

Rasch-Partial Credit

10 ADL-IADL

(zero items misfit)

3 (limited by health)

Community-dwelling, n = 75, Age 60+, M 75.9, SD 8.5,

76% female

TIF: 4.5

Schumacker, 2004 (LH) [16]

†

Rasch-Partial Credit

9 ADL- IADL

(3 items removed)

2 (assessing fear)

Independent living facility (ILF), Age 65+, n = 91

IS Index: 3.01

PS reliability: .64

McHorney & Cohen, 2000 [69]

†

2-Parametric Graded Response Model

166 ADL-IADL items derived through test equating

6 (difficulty)

Veterans Association sample with 75% being male, Age ≥ 65, n = 3358

Not reported

Kempen & Suurmeijer 1990 (LH) [38]

†

Mokken Scaling

18 ADL &IADL

(zero item violations)

3 (difficulty)

Noninstitutionalized, Age 60 +, M = 74.5 n = 101, new users of prof. home help, 77% female

Rho coefficient.: 0.96

Kempen et al., 1995 [59]

Groningen Activity

Restriction Scale (short)

Mokken Scaling

12 ADL-IADL

2 (difficulty)

182 residents of seniors' apartments, M = 75, n = 182

Rho coeff.: 0.87

Kempen et al., 1996

[73]

Groningen Activity Restriction Scale (GARS)

Mokken Scaling

18 ADL-IADL (zero item violations)

4 (difficulty)

Commuity-based sample, Age ≥ 57, n = 4773

Rho coeff.: 0.93

Watson et al., 2010 [68]

Townsend Functional Ability Scale

Mokken Scaling

6 items

(3 item violations)

3(difficulty)

Community-dwelling, All age 79,

n = 548

Rho coeff.: 77