Table 1 Known-groups validity of the Late-Life Function and Disability Instrument

Foster et al. 2011 [27]

Disability (IR)

Lower body obesity vs. central obesity group:

No between-group differences in men or women for IR.

Gibson et al. 2010 [29]

Function (overall) Disability (FREQ, LIM)

Community dwellers vs. retirement dwellers and males vs. females: Overall function discriminated between both groups (p = 0.015 and p < 0.001, respectively).

Community dwellers vs. retirement dwellers:

No between-group differences in FREQ or LIM.

Males vs. females:

FREQ (p = 0.013) discriminated between groups.

Gitlin et al. 2012 [30]

Function (overall)

Female vs. male and depressed vs. non-depressed:

Overall function differed in both groups (p < 0.01 and p < 0.001, respectively).

Haley et al. 2002 [5]

Function (overall, UE, BLE, ALE)

Functional limitation groups measured by the PF-10:

Overall function and ALE discriminated between severe vs. moderate, moderate vs. slight and slight vs. none (all p < 0.0167). BLE and UE discriminated between severe vs. moderate and moderate vs. slight (all p < 0.0167).

Jette et al. 2002 [6]

Disability (FREQ, LIM, SR, PR, IR, MR)

Functional limitation groups measured by the PF-10:

FREQ, SR, LIM and IR all discriminated between severe vs. moderate, moderate vs. slight and slight vs. none groups (all p < 0.0167). PR discriminated between moderate vs. slight (p < 0.0167).

Julius et al. 2012 [36]

Function (overall, BLE, ALE) Disability (LIM)

No exertion during walking vs. some exertion during walking:

No exertion during walking vs. some exertion during walking:

Overall function (p = 0.011), BLE (p = 0.012) and ALE (p = 0.022) all discriminated between groups.

LIM (p = 0.024) discriminated between groups.

Kafri et al. 2012 [37]

Function (overall, UE, BLE, ALE) Disability (LIM, FREQ, IR, MR, SR, PR)

Urgency urinary incontinence (UUI) vs. age-matched controls: Lower overall function (p < 0.001) and ALE (p < 0.001) in those with UUI.

Urgency urinary incontinence (UUI) vs. age-matched controls:

No differences between groups in Disability.

Karp et al. 2009 [38]

Disability (LIM, FREQ)

Not depressed vs. depressed:

Lower FREQ and LIM scores in depressed (both p < 0.001).

Kerr et al. 2012 [40]

Function (overall)

<30 min physical activity vs. 30 + min physical activity: Function differed between groups (p = 0.002). <30 min outdoors vs. 30+ min outdoors: Function differed between groups (p = 0.007).

Li et al. 2012 [47]

Function (overall) Disability (LIM, FREQ)

High habitual gait speed (HGS) vs. moderate vs. low: Function (overall) (p < 0.001) discriminated between groups.

High habitual gait speed (HGS) vs. moderate vs. low: LIM (p < 0.001) discriminated between groups.

Lowe et al. 2009 [48]

Function (BLE, UE, ALE)

Walking ≥ 30 min/day vs. walking < 30 min/day and walking ≥ 60 min/day vs. walking < 60 min/day:

Trend for higher ALE in subjects who walked ≥ 30 min/day (p = 0.17) and in ≥ 60 min/day group (p = 0.10).

Melzer & Kurz 2009 [51]

Function (BLE, UE, ALE) Disability (LIM, FREQ)

Non-fallers vs. one-time fallers vs. recurrent fallers:

Non-fallers vs. one-time fallers vs. recurrent fallers:

Overall function (p = 0.04) and BLE (p = 0.03) discriminated between recurrent fallers and non-fallers.

No differences between groups.

Melzer et al. 2007 [52]

Function (overall, UE, BLE, ALE), Disability (FREQ, LIM, SR, PR, IR, MR)

Cane vs. non-cane (NC) users:

Cane vs. non-cane (NC) users:

Overall function (p = 0.001), UE (p = 0.004), BLE (p = 0.001), ALE (p = 0.003) all discriminated between groups.

LIM (p < 0.001), IR (p < 0.001), MR (p = 0.001), FREQ (p = 0.047) and SR (p = 0.046) all discriminated between groups. Trend for a difference in PR (p = 0.16).

Porensky et al. 2009 [61]

Disability (FREQ, LIM)

Controls vs. those with Generalized Anxiety Disorder (GAD) without comorbitidy (CM) vs. those with GAD and CM:

Both FREQ and LIM discriminated across groups (p < 0.001). Post-hoc analysis showed FREQ and LIM differed in both GAD groups vs. controls.

Sayers et al. 2004 [68]

Function (overall, UE, BLE, ALE) Disability (LIM, FREQ)

Mobility limited vs. non-mobility limited based on 400 m walk: Overall function, UE, BLE, ALE all discriminated between groups (all p < 0.01).

Mobility limited vs. non-mobility limited based on 400 m walk:

LIM and FREQ both discriminated between groups (both p < 0.01).

Segal et al. 2013 [69]

Function (ALE)

High vs. moderate vs. low functioning based on chair-stand test:

Men in the high-functioning group reported higher ALE than those in the moderate and low-functioning groups (p = 0.004).

Shahar et al. 2009 [72]

Function (overall, BLE) Disability (LIM)

Fallers vs. non-fallers:

Fallers vs. non-fallers:

Trend for difference in overall function (p = 0.06) and BLE (p = 0.16).

No difference in LIM between groups.

Sriwattanakomen et al. 2010 [73]

Disability (LIM, FREQ)

Black vs. white:

LIM greater in blacks vs. whites (p = 0.02). FREQ not different between groups.