Introduction

Autism spectrum disorder (ASD) is a complex developmental disorder that can lead to dysfunction in social communication, interaction, and restrictive, repetitive pattern of behavior. Since 2013, Diagnostic and Statistical Manual 5 (DSM-5) included sensory disorder as a symptom under the latter category. Sensory processing disorder in ASD often yields difficulty in regulating responses to sensation and specific stimuli that limits the ability to participate in normal life routines.1,2

Autism is one of the emerging neurodevelopmental disorders in the twentieth century. Studies showed a remarkable increasing prevalence of ASD. Therefore, screening for suspected symptoms is mandatory.3,4,5,6 Sensory integration occupational therapy (SI-OT) based on Ayres theory is a common method to increase the ability to process and integrate sensory information and thereby demonstrate improvement in positive adaptive behaviors. Most studies showed that SI-OT only had low to moderate evidence in older children.7,8,9

Based on clinical experience and observation of pediatric neurologists in Indonesia, SI-OT might be useful as an ASD treatment for younger children especially those under 5 years.10,11 This is due to the benefits of SI-OT by Ayres theory such as exposure to multisensory experience, individual-tailoring, active engagement of the child, the establishment of a therapeutic alliance between the child and therapist, targeting the just-right challenge, and providing within the context of play suitable for young children.12 According to this condition, we conducted a study to evaluate the effect of SI-OT in improving the positive behavior of children aged 2–5 years with ASD.

Methods

Participants

Subjects who fulfilled the diagnostic criteria of ASD from DSM-5 were selected from Check My Child Clinic (CMC), Anakku Clinic, and Harapan Kita Growth Developmental Clinic Jakarta from March 2019 to August 2021. The inclusion criteria for intervention and control group were (1) recently diagnosed ASD with DSM-V criteria in children aged 2–5 years, (2) the subject had never participated in SI-OT or had only participated in SI-OT for less than 1 month in CMC, Anakku Clinic, and Harapan Kita Growth Developmental Clinic, and (3) parents gave informed consent for interviews, whereas additional inclusion criterion for the interventional group was that the subjects completed the SI-OT in twice a week for 12 weeks (24 times), 60 min for each session without any other kind of therapies or medications. The exclusion criteria for intervention and control group were that (1) the subjects were accompanied by other comorbidities (such as epilepsy, cerebral palsy) or genetic syndromes that caused sensory processing disorder, (2) abnormal growth status (such as microcephaly, stunting, malnutrition), (3) consumption of any medications, and (4) attending any other therapies.

Material and designs

Subjects were assessed using the Vineland Adaptive Behavior Scale-II tool by a pediatric psychologist. It consisted of communication domains (including expressive, receptive, written subdomain), socialization domains (including interpersonal relationship, play and leisure time, coping skill subdomain), and daily living skills domains (including personal, domestic, community subdomain). The assessments were conducted pre and post therapy for each intervention and control group with analyzing the difference (delta) score of pre and post therapy between both groups. The effect of SI-OT intervention was evaluated with a non-randomized controlled trial, because of the ethical reason that the main intention of all subjects attending the clinics was to seek therapy. The study design compared a group of participants receiving SI-OT intervention with a historical control group from the same population.

Procedures

The subjects from the intervention group received SI-OT in accordance with the clinics' protocol with the frequency of two times per week, for 1 h long each session, for 12 weeks (24 times), 60 min for each session. The SI-OT exposed subjects to multisensory stimulations through play method based on good fidelity of Ayres theory on structural and process elements according to Parham et al. study (Tables 1 and 2).12 These interventions are individually designed based on their sensory profiles. This therapy aimed to stimulate and involve the subjects in reciprocity interaction, improve subjects’ comprehension toward instructions in order to give appropriate responses as well as increase subjects’ awareness of surroundings.

Table 1 Structural elements of sensory integration occupational therapy of Ayres theory.
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Table 2 Process elements of sensory integration occupational therapy of Ayres theory.
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On the contrary, subjects from the control group did not receive any therapies.

Data were collected two times using the Vineland Adaptive Behavior Scale-II tool by a pediatric psychologist from the caregiver's report before beginning the therapy and after completion of the SI-OT twice a week for 12 weeks (24 times), 60 min for each session in the intervention group. In the control group, data were collected at the first meeting and 12 weeks afterward without therapy. The obtained data from caregivers were confirmed with therapist and neuropediatric clinical evaluation. Domain standard scores (from domain items) and v-scale scores (from subdomain items) for each group were compared.13

Analysis

The data analysis was performed using the Mann–Whitney test for data that were not normally distributed, and t-test independent analysis for normally distributed data. This study used Program Software SPSS vers.25.

Results

A total of 72 ASD subjects aged between 2 and 5 years were studied. Most subjects were of 3 years in both intervention and control groups (38.9 and 38.9%, respectively), and the boys-to-girls ratio was 2.3-to-1 in the intervention group and 3-to-1 in the control group. Table 3 presents the characteristics of subjects and caregivers.

Table 3 Demography characteristics.
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Data of the communication domain, as well as receptive and expressive subdomains after SI-OT in the intervention group, were improved significantly compared with the control group (p = 0.003; p = 0.002; p = 0.001, respectively) (Table 4).

Table 4 Delta score (pre-post) comparison of domain and subdomain.
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Significant improvements were also achieved in the socialization domain (p = 0.002) including the coping skills subdomain (p < 0.001), compared with the control group (Table 4).

Daily living skills domain with personal and community subdomain showed significant improvement after SI-OT intervention (p = 0.005; p = 0.044; p < 0.001, respectively) compared with the control group.

Discussions

The current study was the first study to address evidence of SI-OT in ASD children younger than 3 years. Our main findings were that subjects with ASD who received SI-OT scored significantly higher in the communication domain and subdomains (expressive, receptive). On the contrary, Pfeiffer et al.14 and Schaff et al.15 showed no significant score difference in the communication domain post therapy using Vineland Adaptive Behavior Scale-II. However, their subjects were older in age and received lesser duration and amount of therapy sessions compared to our study. In addition, Iwanaga et al.16 also stated that verbal communication was not improved significantly, but non-verbal communication significantly improved after SI-OT. The study was applied to older children with a longer duration of therapy and using different tools.

Better communication after SI-OT is not defined solely by its structural elements, such as specific activities during therapy, rather it includes elements of process as well, such as the therapeutic relationship, motivation, and collaborative atmosphere between child and therapist. Thus, sensory modulation improvement post SI-OT will increase attention in ASD children, in order to support a higher level of processing ability that is needed to communicate.17

Our study also found significant improvement scores in the socialization domain and coping skills subdomains after SI-OT. On the contrary, Pfeiffer et al.14 and Schaff et al.15 showed no significant score difference in the socialization domain post therapy using Vineland Adaptive Behavior Scale-II. Their subjects’ age was older and they received lesser duration and amount of therapy session.

Improvement in sensory modulation and praxis skills after OT-SI may underlie the gain that is seen in social skills. It is likely that behavior regulation also improves and subsequently children with ASD are able to participate in social activities.15 The coping skill needs complex responsibility and sensitivity to the surrounding. It also requires flexibility and responsiveness to contextual demands as well as cognitive level.18

The result in daily living skills domain including personal and community subdomains after SI-OT improved significantly in our study. These findings were different from Pfeiffer et al.14 and Schaff et al.15

A study by Pugliese et al.19 stated that higher IQ, younger age, fewer problems with initiation, organization of material problems, and working memory difficulties were significant predictors of better daily living skills behavior. In addition, these daily living skills require routine stimulations by caregivers in order to gain better ability.20,21

Conclusions

We found that good fidelity of Ayres theory SI-OT in 60 min twice a week for 12 weeks could improve positive behaviors, particularly in the communication domain (including expressive and receptive subdomain), socialization domain (including coping skills subdomain), and daily living skills domain (including personal and community subdomain). These results of SI-OT will be a good reference therapy for ASD children in order to improve and increase communication, interaction, and daily living skills.