Complications with
Assessing Disability in Aged
Care: When Does “Does
Not Apply” Apply?
E. Helmes & A. Campbell
Department of Psychology
James Cook University
Disabilities are common in residential care
facilities
 Severe levels of disability may affect other
domains of function
– Example: impaired mobility limits social
interactions

Many rating scales and self-report
instruments include a neutral, or “Cannot
Say” option
Examples: early MMPI, 16PF (5th edition),
Likert scales with uneven number of
options (5-, 7-, or 9-point scales)


Responses to such neutral points are
ambiguous:
– Neutral?
– Indifferent?
– Lacks understanding of content?
– Lacks knowledge need to answer?
– Hostility?
What of seemingly more direct “Does Not
Apply” or “Not Applicable” options?
 Bristol Activities of Daily Living Scale
(Bucks et al., 1996) – all 19 items
 MOSES (Helmes, et al., 1987) – 18 of 40
items

11. FINDING WAY AROUND INSIDE: (For example, ability to find his room, the
washroom, the dining room)
How often during the daytime in the past week did the resident become
disoriented (confused) in finding his or her way around the inside of
the residence?
1. Not at all
2. Seldom
(only one to three times during the week)
3. At times
(either once or twice a day on more than three days,
or several times a day on one to three days)
4. Often
(several times a day or on more than three days)
5. Question does not apply -- the resident never moved around inside
the building without assistance from the staff
Content Interpretation?
Pruchno et al. (1988):
 5 of 18 items – inability to speak implies
greater levels of disability, so score as 5>4
 11 items equivalent to non-occurrence, so
equate with “Not at All”, so score as 5=0
 536 nursing home residents, 24/40 items
retained after changed scoring &
confirmatory factor analysis

Samples

Norming sample; 2921 unique cases
– Psychogeriatric – 397
– Nursing home – 918
– Home for the Aged – 563
– Continuing Care – 447
924 (31.6%) males, 1985 (68%) females
 Mean age 78.9 (SD = 10.9)
 490 Single, 688 Married, 1588 Widowed,
123 Divorced or Separated

Scoring Variations
All “Does Not Apply” coded as “5”
 Pruchno et al. variation
 Listwise deletion of any case with a “Does
Not Apply” score (as in 1987 components
analysis)

Analysis
Scoring key as target: 8 items on each of
5 dimensions
 12 covariance matrices (3 scoring
variations x 4 samples)
 EQS confirmatory factor analysis
 M-Plus distribution-free confirmatory
analysis

Results
All solutions not optimal: cross-loading
items
 Fewer model mis-specifications with MPlus
 No clear pattern: M-Plus suggests poorer
fit with ‘Exclude’ scoring option (CFI; but
not RMSEA)

Results: Method of Analysis
80
70
60
50
Number
Modifications
40
30
20
10
0
EQS
M-Plus
Method of Analysis
Results: Method of Compensation CFI
0.84
0.82
0.8
0.78
EQS
M-Plus
0.76
0.74
0.72
0.7
Convert to
Higher Score
Pruchno
Method of Compensation
Deletion
Results: Method of Compensation RMSEA
0.095
0.09
0.085
EQS
M-Plus
0.08
0.075
0.07
Convert to
Higher Score
Pruchno
Method of Compensation
Deletion
Results: Method of Compensation –
Number of Low Loadings
25
20
15
EQS
M-Plus
10
5
0
Convert to
Higher Score
Pruchno
Method of Compensation
Deletion
Results
Pruchno approach more model misspecifications
 Pruchno approach more marginal loadings
 Exclude approach fewest marginal
loadings, mis-specifications with EQS (not
so with M-Plus)
 Deletion method results in fewer items
with low loadings (i.e. clearer structure)

Conclusions
Minimal differences across methods of
compensation for “Does Not Apply” option
 No method gives univocally better fit
 Listwise deletion gives clearer structure
but at cost of smaller and likely biased
sample

Alternative: Item Response Theory
IRT provides information on performance
of response options
 Preliminary results of analysis of nursing
home data using GGUM (Roberts et al.,
2004): Generalized Graded Unfolding

Model
Withdrawal Item 40: “Does not Apply” = Most Severe
10 of 18 items