Abstract
The SP3D OPS was found to show promise as a measure of occupational performance and should be included as part of a comprehensive occupational therapy evaluation of children with sensory processing and integration challenges.
Children with sensory processing and integration challenges make up a large percentage of those seen in pediatric occupational therapy practice (Mailloux & Smith Roley, 2010). Sensory processing and integration globally describes the ability to regulate one’s responses to sensory experiences in an adaptive manner and to integrate bodily and environmental sensory experiences to act in the world (Miller, 2014). Challenges or dysfunction in sensory processing and integration have consistently been shown to influence participation in everyday life activities across occupations and contexts (Bar-Shalita et al., 2008; Chien et al., 2016). This ability to engage in daily occupations in the environment is referred to in the occupational therapy literature as occupational performance (OP; Law et al., 1996). Occupations reflect the everyday activities that give meaning and purpose to one’s life (American Occupational Therapy Association [AOTA], 2020). Therefore, occupational therapy services are often recommended for people whose sensory processing and integration deficits interfere with OP. Moreover, the occupational therapy profession has an interest in gaining a better understanding of the relationship between underlying sensory processing and integration problems and differences and the impact on OP (Mulligan, 2017). A growing body of evidence suggests that these symptoms often affect all areas of daily functioning, including activities of daily living (Chien et al., 2016), social and community participation (Cohn et al., 2014), school performance (Koenig & Rudney, 2010), and play and leisure (Cosbey et al., 2010).
The recognition of sensory processing and integration impairments in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; American Psychiatric Association, 2013) criteria for autism spectrum disorder and in other classification systems, such as the DC:0–5™ Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (Zero to Three, 2016) has increased the need for more performance-based, objective, reliable, and valid tools for measuring sensory processing and integration dimensions. The Sensory Processing Three Dimensions (SP3D) Assessment was developed in response to this need; in its development, the SP3D Occupational Performance Scale (SP3D OPS) was added to allow for a more comprehensive occupational therapy assessment by including a measure of impact on participation in daily life. This article reports on initial studies of the internal consistency and discriminant validity of the SP3D OPS and examines the relations between sensory processing and integration and OP.
OP assessments are integral to the delivery of health care services for children and adults with sensory processing and integration challenges (Mulligan, 2017). A systematic review of 35 studies found that people with sensory processing and integration challenges had deficits in the performance of tasks and activities associated with many areas of occupation (Koenig & Rudney, 2010).
Studies have also examined whether certain sensory processing and integration subtypes are associated with specific kinds of OP problems. One study found that only sensory sensitivity and sensory avoiding (e.g., sensory overresponsivity) were associated with low activity and social and school performance (Reynolds et al., 2017). However, this study did not provide domain-specific information or information about posture, praxis, or discrimination impairments. Another study found several domain-specific associations; low energy and weak behaviors (similar to postural challenges) were associated with decreased participation in informal activities, visual and auditory overresponsivity were associated with lower participation in self-improvement activities, and sensation seeking was associated with decreased participation in activities in the home (Hochhauser & Engel-Yeger, 2010). Ricon et al. (2017) found that children’s ability to process tactile, vestibular, and visual and auditory information correlated with their level of independence in daily routines. Moreover, they suggested that skilled processing of sensory stimuli contributes to successful participation in play, leisure, and daily routines.
Because improving a client’s OP is the primary goal of occupational therapy, it is surprising that more assessment tools are not available for this purpose. Many of those that are available were designed for use with specific populations, and others target only a single area of occupation, such as self-care skills or play. Family-centeredness and parent involvement in the therapy process are highly valued as essential for the delivery of high-quality services, so caregivers such as parents are important informants throughout the process of assessing the child (Missiuna et al., 2006).
The use of parent-report questionnaires and interview tools related to OP has been shown to be an effective and efficient method for gathering information from the parent’s perspective and a way of involving the family in the evaluation process (Law et al., 2019). However, few measures have been developed that address the unique participation challenges of children with sensory processing and integration impairments. The Participation in Childhood Occupation Questionnaire (Bar-Shalita et al., 2009) was developed for children with sensory processing and integration challenges and is somewhat similar to the SP3D OPS. However, the SP3D OPS is more comprehensive in that it includes items to assess social participation and relationships with both family members and peers as well as competency in performing specific daily routines. Moreover, to help target key therapy goals, the SP3D OPS rates areas of occupation in terms of priorities for change.
Evidence suggests that engaging families in the evaluation process serves as a mechanism for establishing rapport, trust, and collaboration in the treatment process (Øien et al., 2010). Cohn et al. (2014) recommended that outcomes research related to occupational therapy interventions for sensory processing and integration challenges focus more on activities of daily living, social participation, and emotional functioning (e.g., self-esteem, community participation) rather than on measuring change in client body functions and motor performance skills. The SP3D OPS is such a measure.
The SP3D Assessment also includes a caregiver-report questionnaire that asks respondents to rate their child’s sensory-related behaviors. This scale, called the SP3D Inventory (Schoen et al., 2016), consists of six subscales: Sensory Over-Responsivity (SOR), Sensory Under-Responsivity (SUR), Sensory Craving (SC), Posture, Dyspraxia, and Sensory Discrimination. This scale differs from existing sensory-related questionnaire such as the Sensory Processing Measure (Parham et al., 2007) and the Sensory Profile 2 (Dunn, 2014) in that it is organized and scored by the sensory processing disorder subtypes proposed in the SPD nosology (Miller, 2014) rather than by sensory system or other theoretical models. Moreover, the SP3D Inventory was designed to parallel and complement the (performance-based) structure and constructs of the SP3D Assessment, allowing for easy comparisons of examiner-administered, performance-based data and parent-report data, and to facilitate the interpretation and synthesis of assessment data from multiple sources. A more detailed description of the SP3D Inventory is provided in the “Method” section.
In this article, we report on the initial psychometric properties of the SP3D OPS and examine relations between sensory processing and integration subtypes and areas of OP. More specifically, the four aims of this study and associated hypotheses were as follows:
To evaluate the internal consistency of each SP3D OPS subscale and of total OP
To evaluate the discriminant validity of the SP3D OPS, with the hypothesis that OP ratings of children with sensory processing and integration challenges will be lower than those of typically developing children
To explore correlations between scores reflecting sensory processing and integration behaviors and skills with competency in performance across different occupational areas, with the hypothesis that there will be small to moderate correlations between sensory processing and integration subtypes and OP
To determine the extent to which sensory processing and integration symptoms and subtypes as measured by the SP3D Inventory predict problems with certain areas of OP on the basis of SP3D OPS scores.
Method
Participants
A convenience sample of 66 children (ages 4–12 yr) participated in this study. Thirty-three were typically developing (M age = 8.9 yr, SD = 3.5; 13 boys, 20 girls), and 33 had sensory processing and integration challenges (M age = 7.1 yr, SD = 2.4; 13 boys, 20 girls). The typically developing sample was 90% Caucasian, and the clinical sample was 85% Caucasian. Socioeconomic status was based on parents’ highest level of education; 59% of the typically developing sample’s parents and 40% of the clinical group’s parents had postcollege education.
The clinical group was recruited from three occupational therapy practices to which children had been referred for assessment and treatment of sensory processing and integration challenges that significantly affected their daily life functioning. Inclusion in this group required verification of sensory processing and integration concerns through a comprehensive occupational therapy evaluation that included parent interview, standardized testing of sensory–motor abilities using the Miller Function and Participation Scales (Miller, 2006) or the Goal Assessment of Life Skills (Miller et al., 2013), parent report of sensory-related behaviors using the Short Sensory Profile (SSP; Dunn, 1999), and clinical observations in the therapy gym of sensory and motor functions. The final determination for placement in the clinical group was based on the occupational therapist’s global clinical impression and criteria that included a score <1.5 SD below the mean on either of the examiner-administered scales and an atypical score on the SSP (total test score <3 SD below the mean or two subtest scores <2.5 SD below the mean). Children with comorbid orthopedic or neurological conditions, such as brachial plexus injury, cerebral palsy, or autism spectrum disorder, or intellectual impairment, such as Down syndrome, were excluded.
Typically developing children were recruited through personal and professional contacts of the researchers. For inclusion in the typically developing sample, parents reported no history of developmental concerns or neurodevelopmental diagnoses, and these children did not participate in therapy or special education services.
Procedures
Data for this study were collected as part of a larger study on the psychometrics of the SP3D Assessment. All children were administered the SP3D Assessment during a single 80- to 90-min testing session while parents completed the SP3D Inventory and the SP3D OPS. Informed consent was obtained from all parents, and assent was obtained from child participants ages 7 yr or older. All procedures for this study were approved by the Rocky Mountain University of Health Professions institutional review board. For the purposes of this study, only raw scores from the SP3D Inventory and SP3D OPS were used.
Description of Measures
Sensory Processing Three Dimensions Occupational Performance Scale
The SP3D OPS was developed to gather information regarding parents’ perceptions of their child’s abilities and participation in daily life activities. Content areas and specific items were selected with the following four considerations:
The areas of occupation described by the Occupational Therapy Practice Framework: Domain and Process (4th ed.; AOTA, 2020) as being within occupational therapy’s domain of practice
Research literature documenting the types of OP problems often experienced by people with sensory processing and integration deficits
Review of data over a 10-yr period from a private clinic serving children and adults with sensory processing problems
Need for ease and efficiency in administration.
The initial content validity of the categories, items, and method of rating was addressed through a series of reviews by an expert panel of seven occupational therapy clinicians, each with more than 15 yr of experience in the field. The SP3D OPS has gone through multiple revisions on the basis of these expert reviews and incorporation of feedback. In its current form, it has six OP categories: Relationships, Routines at Home (Routines), Activities of Daily Living (ADLs), Family Activities Outside the Home (Family), School Activities (School), and Play/Extracurricular Activities (Play), with a total of 16 questions or items.
The SP3D OPS is scored on a visual analog scale (VAS), represented by a 10-cm horizontal line for each item. As is customary with a VAS, the line represents a continuous variable anchored by two verbal descriptors, low and high. Caregivers rate each item by placing a slash through the line between the low and high endpoints where they feel their child’s performance best fits. Distance is then measured from the beginning low end of the line to the slash mark, yielding a score (maximum = 10) recorded to the nearest 0.5 cm. Scales without numbers or additional verbal descriptors have been shown to minimize scoring bias around a preferred numeric value. Each item is scored for Competency, reflecting the child’s ability level for that functional skill, and for Priority, which represents the extent to which the parent feels the area of function is an important area for change or to be addressed with their child.
Total Competency and Priority scores were calculated for each of the six OP categories by summing the scores from each item within a given category. Competency scores were then summed across the six categories to produce a total OP competency score.
Sensory Processing Three Dimensions Inventory
The SP3D Inventory is a parent–caregiver measure of sensory-related behaviors associated with performance and participation in daily life. Its six subscales—three modulation subscales, SOR, SUR, and SC; a Sensory Discrimination subscale; and two sensory-based motor subscales, Posture and Dyspraxia—reflect behavioral symptoms of sensory processing and integration challenges. The SP3D Inventory subscales use a binary scoring system in which each behavior or item is scored as being present (1) or absent or not applicable (0).
The SP3D Inventory takes approximately 20 min to complete, and the version used in this study consisted of a total of 173 items organized by subscale: SOR, 47 items; SUR, 21 items; SC, 28 items; Discrimination, 17 items; Posture, 23 items; and Dyspraxia, 37 items. Previous research supports the SP3D Inventory’s reliability and validity with acceptable internal consistency, reliability, and discriminative validity (Schoen et al., 2016). Principal-components factor analysis confirmed aspects of the internal structure of the subscale groupings (Schoen et al., 2016). Total scores were provided for each subscale by summing the items endorsed by the parent for each subscale. Higher scores suggest greater impairment.
Data Analysis
Data analyses were selected according to each study aim. Internal consistency reliability of the SP3D OPS subscales and total OP were computed using Cronbach’s α for all Competency and Priority scores. Descriptive statistics were used to characterize the OP of the children with sensory processing and integration challenges. Discriminant validity was examined using Mann–Whitney Us to compare Competency and Priority scores between the clinical group and the typically developing group on each of the 16 items and for each of the six OP categories.
To explore relations between sensory processing and integration characteristics and the different OP categories, nonparametric Spearman’s r s correlation coefficients were computed between the parent-reported sensory-related behaviors on the SP3D Inventory and each of the OP categories of the SP3D OPS. Correlations were computed between Competency and Priority scores as an indicator of construct validity.
Finally, to determine whether atypical sensory processing and integration predict problems with OP, stepwise linear regressions were conducted. These analyses allowed for examination of the relative contributions of targeted subtypes in predicting total OP competence (e.g., total Competency score) as well as each OP area (e.g., each Competency category score). Variables entered into the model were total scores for SOR, SUR, SC, Sensory Discrimination, Posture, and Dyspraxia. IBM SPSS Statistics (Version 25; IBM Corp., Armonk, NY) was used for all analyses, and an α level of p < .05 was set to determine statistical significance for the inferential analyses and correlations. Because of the preliminary and exploratory nature of these analyses, no correction was made for multiple comparisons.
Results
Internal consistency values for Competency and Priority are reported in Table 1. With one exception, the Cronbach’s α values indicated moderate to excellent internal consistency, ranging from .74 to .93. The one exception was the Priority score for Relationships (α = .43).
Internal Consistency of the SP3D OPS Competency and Priority Scores
Note. N = 66. ADLs = activities of daily living; Extracurricular = Play/Extracurricular Activities; Family = Family Activities Outside the Home; SP3D OPS = Sensory Processing Three Dimensions Occupational Performance Scale.
The clinical group was found to have lower Competency than the typically developing group across all areas of OP (see Table 2). Also, all categories of OP were almost equally as problematic, with slightly more concerns noted in Routines at Home. Item analysis revealed that the lowest scoring question in Competency concerned relationships with peers (M = 5.38, SD = 2.76). Mean Priority scores were significantly higher for the clinical group for performance related to ADL, Family, School, and Play. The category rated highest by the clinical sample for Priority was Relationships; for typically developing children, the category rated highest for Priority was related to School.
Comparison of Competency and Priority Scores Between Clinical and Typically Developing Groups
Note. ADLs = activities of daily living; Extracurricular = Play/Extracurricular Activities; Family = Family Activities Outside the Home; OPS = Occupational Performance Scale.
Moderate to strong significant, negative correlations were observed between Competency and Priority scores in each category, with r s values as follows: Relationships, −.44; Routines, −.55; ADLs, −.71; Family, −.65; School, −.70; and Play, −.65. Those areas rated lowest for Competency were rated highest in Priority.
Scores from the SP3D Inventory had moderately significant correlations (ranging from r s = −.26 to −.62) with the Competency scores from each SP3D OPS category (see Table 3), with the exception of ADLs with SUR (r s = −.24). SC and Dyspraxia had the strongest correlations with OP areas, and SUR had the weakest. All areas of OP were quite comparable with respect to the strength of their relations with sensory processing characteristics, with slightly stronger correlations noted with School, Relationships, and Routines.
Spearman’s Rank-Order Correlations Between Competency and Inventory Scores
Note. ADLs = activities of daily living; Extracurricular = Play/Extracurricular Activities; Family = Family Activities Outside the Home; OPS = Occupational Performance Scale; SC = Sensory Craving; SOR = Sensory Over-Responsivity; SP3D = Sensory Processing Three Dimensions; SUR = Sensory Under-Responsivity.
p = .05. ** p = .001
Separate stepwise regression analyses were conducted between SP3D Inventory and SP3D OPS Competency scores, with SP3D OPS Competency scores for each occupational domain (and Total) as the dependent variable and SP3D Inventory scores for each disorder subtype as the independent predictor variables. Results are summarized in Table 4. Statistically significant models were obtained for each dependent variable. The results indicated that SOR, Dyspraxia, or both most often predicted competency in OP areas, with the exception of Family, which was predicted by Posture, SOR, and SC.
Stepwise Regression Models
Note. All ps < .001. Adj. = adjusted; SOR = Sensory Over-Responsivity.
Discussion
This study provides preliminary support for the reliability and validity of the SP3D OPS. Internal consistency analyses confirmed that the items on each subscale have commonality and hold together as a well-defined construct. The items for the Total scale showed strong internal consistency, suggesting that the SP3D OPS items are all associated with the single construct OP. The SP3D OPS Competency and Priority scores were able to discriminate typically developing children from those with sensory processing and integration challenges, suggesting that the rating scale and items were adequately sensitive to detect differences in OP between the two groups. Moreover, the tool was able to detect performance deficits in the group of children with sensory processing and integration challenges. An interesting finding was that the only scores that were not significantly different between the typically developing and clinical groups were the Priority scores for Relationships and Routines. A possible explanation is that these areas of function are important to all parents, regardless of how well they believe their children are doing.
In addition, this study demonstrates the value of using a parent-report measure that asks about OP priorities for change in addition to child competencies. Engaging parents during the assessment process in a discussion of areas of concern in daily life is of utmost importance to the provision of family-centered care (Missiuna et al., 2006) and for determining meaningful intervention goals. Parent-report measures such as the SP3D OPS can assist therapists in gaining knowledge about the child’s and the family’s particular circumstances and the impact of sensory processing and integration challenges on OP problems in their daily lives. This knowledge can facilitate the collaborative process during intervention that is central to the provision of occupational therapy services (Mattingly & Fleming, 1994).
The correlational results support the notion that underlying sensory integration and processing challenges are related to deficits in all areas of OP. These results are consistent with those of previous reports concluding that children with sensory integration and processing challenges often experience difficulties with social participation and performance of daily life activities (Cohn et al., 2014). Moreover, our exploration of such relations suggests that the extent and area of OP deficits seen in children with sensory processing challenges are somewhat dependent on the type of sensory processing and integration problem involved.
A better understanding of the strength of such associations between sensory processing and integration problems and OP can assist practitioners in targeting parent interviews, as can administering assessments directed toward potential or hypothesized areas of concern. Once deficits are confirmed, such knowledge can also assist in intervention planning and in the provision of more targeted interventions. The regression analyses in this study expanded on previous correlational research by exploring the potential of sensory processing and integration characteristics in predicting OP problems. Although these results are exploratory in nature, the findings suggest that specific sensory processing and integration deficits have some predictive value for determining potential areas of concern. For example, Dyspraxia and SOR were the strongest predictors of overall OP, as was competency related to participation in routines at home and extracurricular activities. Dyspraxia alone was the strongest predictor of competency in relationships and school activities.
Thus, the presence of dyspraxia might be a risk factor that needs to be explored when considering the impact of sensory processing and integration challenges on daily life. This study’s findings that dyspraxia was one of the strongest predictors of OP deficits suggests that the ability to initiate, plan, organize, sequence, and execute motor actions is central to a child’s daily functioning. In addition, if dyspraxia is the strongest predictor of overall OP, these children may be at greater risk of more widespread deficits in everyday activities; this finding can help therapists anticipate dosage of services that might be needed to address the areas affected.
Limitations to this study include the relatively small convenience sample of typically developing children and clinical cases. Children recruited from private clinics may not be representative of all children with sensory processing and integration problems. Although the typically developing sample was carefully screened, it is possible that a child in this group may have had an undiagnosed sensory processing and integration difficulty. The measures used in this study were exclusively based on parent report. Although such measures have been criticized for introducing potential bias, an abundance of literature supports the reliability and value of caregivers’ unique perspectives on their child’s behavior (Ferdinand et al., 2003). Because the SP3D OPS and SP3D Inventory are new measures, there are few psychometric data available supporting them for these purposes. Directions for further research include ongoing exploration of the relations between OP and sensory processing and integration abilities with larger and more diverse clinical and nonclinical samples. Further study of the psychometric properties of the SP3D OPS and SP3D Inventory and normative data collection for both these tools are also needed.
Implications for Occupational Therapy Practice
The SP3D OPS is a new measure that contributes vital information to the assessment of children with sensory processing and integration challenges and acknowledges the importance of family-centered care. Implications for occupational therapy practice are as follows:
A comprehensive sensory-based assessment should reflect the areas of OP affected.
Engaging parents in identifying concerns and priorities can be facilitated through use of an OP measure.
Assessment that incorporates family priorities is essential to treatment planning.
Clinicians should consider how sensory processing and integration challenges may differentially affect areas of OP.
Conclusion
This study provides preliminary support for the psychometric characteristics of the SP3D OPS. Evidence of internal consistency reliability and discriminant validity was found. Relations were also found between sensory processing subtypes and competency in several areas of occupational performance. SC and Dyspraxia had the strongest association with occupational performance areas, and SUR had the weakest association. All areas of occupational performance were comparable with respect to the strength of their relations with sensory processing characteristics, with slightly stronger associations noted with School, Relationships, and Routines. The Dyspraxia and SOR subscales best predicted deficits in occupational performance.
The SP3D OPS shows promise as a measure of occupational performance. The occupational performance deficits among children with sensory processing and integration challenges are due in part to subtype presentation. Further studies of the SP3D OPS’s reliability and validity are needed. The SP3D OPS should be included as part of a comprehensive occupational therapy evaluation for children with sensory processing and integration challenges. This information provides therapists with preliminary information related to identifying concerns that are relevant to creating family-centered goals and addressing priorities for intervention.
Footnotes
Acknowledgments
The authors disclose a relationship with Western Psychological Services, with whom they have a contract to publish the Sensory Processing Three Dimensions Measure described in this study. No payment or royalties have been received. The authors acknowledge Carrie Schmitt for assisting with data collection and Andrea Valdez for assisting with data management and data analysis.