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and teacher felt he just had behavior
problems, he did not qualify for occu-
pational therapy services in school. At
the suggestion of a friend, Thomas’s
mother contacted an occupational
therapist in a clinic setting. As part
of the assessment, both the Home
and Main Classroom SPM forms were
completed. The results confi rmed that
Thomas’s challenges at school were
related to sensory processing. When
Thomas’s mother completed the SPM,
she realized that Thomas had extreme
responses to sensory input in his home
and community that she had never
noticed before, because she had been
unknowingly accommodating him. For
example, Thomas was bothered by the
feel of his sheets and clothing; seemed
to not get dizzy; leaned on other peo-
ple; and tended to do everything with
too much force, including petting his
neighbor’s dog and hugging his mother
and sister. The SPM results enabled the
clinic-based therapist to identify goals
that would be medically relevant and
reimbursed by the insurance carrier
(i.e., in 6 months, Thomas will dem-
onstrate increased body awareness
when hugging his mother and sibling
as demonstrated by appropriate force,
lack of injury, and no expression of pain
or discomfort from either recipient,
90% of the time). In addition, the SPM
enabled the clinic-based occupational
therapist to provide suggestions for
sensory-based activities that could be
infused into Thomas’s school day (i.e.,
more movement opportunities between
deskwork activities because his SPM
scores refl ected dysfunction in his
vestibular and proprioception systems.
These suggestions resulted in Thomas
being able to listen more attentively
and sit still more often.
Case Example: Food Sensitivity
Seven-year-old Sera was referred to
occupational therapy because of her
narrow, unhealthy repertoire of foods.
Her scores on the SPM fell in the
typical range, potentially indicating
that there were other reasons for her
disordered eating. However, as the SPM
manual indicates, the therapist should
examine individual items if there is any
reason for concern.
1
A review of the
SPM questions with Sera’s parents, and
clinical observations, indicated sensory
integration problems. For example,
Sera’s parents commented that she
“never” had certain responses to sen-
sory input because she had “overcome”
her sensitivities. When answering
the SPM item, “Does your child show
distress at smells that other children
do not notice?” they reported that she
was not distressed, but she noticed the
slightest fragrances or odors. The SPM
item analysis indicated slight varia-
tions in scores, thus clinical reasoning
yielded additional information, allowing
for a more specifi c intervention plan
and leading Sera to tolerate and accept
a greater range of different nutritious
foods, with less tension during meals.
PSYCHOMETRIC STRENGTH
OF THE SPM
For an assessment tool to be reliable
for clinical practice, it must provide
accurate and consistent information.
This section summarizes evidence dem-
onstrating that the SPM is a valid and
reliable measure of sensory processing,
praxis, and social participation.
The SPM was developed with a
large, demographically representative
normative sample, consisting of 1,051
typically developing children, ranging
in age from 5 to 12 years. The norma-
tive sample was roughly divided among
males and females, ethnically diverse,
and representative of various levels of
socioeconomic status.
A normative sample provides clini-
cians with the expected SPM scores for
typically developing children. There-
fore, when determining whether a child
has a sensory processing disorder, the
clinician simply compares the SPM
scores to the average scores of the
normative sample. This comparison
classifi es the child into one of three
SPM interpretive ranges: (1) typical,
(2) some problems, or (3) defi nite
dysfunction.
Some measurement error is possible
in all tests. When developing the SPM,
a premium was placed on establishing
high reliability, or reducing the amount
of measurement error as much as
possible. One important aspect of reli-
ability is internal consistency, which
expresses how well the items of the
SPM “hang together” to measure clear,
well-defi ned aspects of sensory pro-
cessing. For example, the SPM Hearing
scale is intended to measure problems
with auditory processing. If some of
the items on the Hearing scale had
measured some other construct (e.g.,
attention span, aggressiveness, etc.),
the Hearing scale’s internal consistency
would have been lower. Internal con-
sistency is expressed as a correlation
coeffi cient that ranges in value from
0 to 1, with higher values indicating
greater reliability. In the SPM norma-
tive sample, all of the scales on the
Home and School forms have internal
consistency greater than .70 (and most
are greater than .80), indicating that
they are reliable enough to support
clinical assessment.
Another important aspect of reliabil-
ity is test-retest reliability, or temporal
stability. The SPM and other behavioral
rating scales are presumed to measure
characteristics of children that are
stable over short periods. For example,
one would not expect a child’s level of
dysfunction in auditory processing to
change appreciably over 2 weeks, all
else being equal. The 2-week test-
retest correlations for the SPM scales
are almost all .95 or above, indicating
excellent temporal stability.
The validity of an assessment has
various facets, some theoretical and
some practical. Discriminant validity
refers to the SPM’s ability to differenti-
ate between typically developing chil-
dren and those with sensory processing
dysfunction. As part of the SPM devel-
opment research, a clinical sample was
collected, consisting of 345 children
FOR MORE INFORMATION
AOTA CEonCD™: Response to Intervention:
A Role for Occupational Therapy Practitioners
By G. Frolek Clark, 2008. (Earn .2 AOTA CEUs
[2 NBCOT PDUs/2 contact hours.] $68 for
members, $97 for nonmembers. To order, call
toll free 877-404-AOTA or shop online at http://
store.aota.org. Order #4826-MI.)
FAQ on Response to Intervention
American Occupational Therapy Association,
2008. Bethesda, MD: Author.
http://www.aota.org/Practitioners/PracticeAreas/
Pediatrics/Browse/School/FAQ-Response-to-
Intervention.aspx
Online chat between school and clinic based
therapists hosted on www.otexchange.com
by Deanna Iris Sava and Diana A. Henry.
Go to www.ateachabout.com home page and
click on Discussion chat about the SPM.
Sensory Processing Measure Web site
www.sensoryprocessingmeasure.com