Weighted Vests Vs. Standard Occupational Therapy on

On-Task Behavior in Children with Autism Spectrum Disorders

Brittney Schorr, MOTS

Agenda• Background• Objective• Intervention• Methodological Quality of Studies• Results• Discussion• Implications for OT Practitioners• Implications for Future Research

BACKGROUND

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On-Task Behavior

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Sensory Integration

• Regulates behavior through sensory systems:– Tactile – Proprioceptive– Vestibular

• SI treatments:– weighted vests– pressured vests– weighted blankets

Weighted Vests• Commonly cloth vests with pockets in

the front and back

• Weights in the pockets

• Weights can be made of any material

Occupational Therapy Treatment as Usual

• Includes:– Music Therapy– Therapy Ball Chairs– Picture Activity Schedules– Hug Machine

Picture Activity Schedule

Hug Machine

Objective• To examine the extent to which the

research literature supports weighted vests as compared to treatment as usual as a more effective approach to improving on-task behavior in children with ASD

Search Terms• Autism• Weighted vest• Therapy• On-task behavior• Attention• Developmental Disorder

Types of Studies

• Controlled Clinical Trials

• Mixed Study Designs

• Experimental Research

• Single Subject

Participants• Children with:

– ASD– Attention deficit hyperactive disorders (ADHD)– Developmental delays

• 2 to 13 years old

• 45 boys, 11 girls (56 total)

Diagnoses & Interventions

4 Autism and PDDFertel-Daly et al.,

2001 Hodgetts et al., 2010

Kane et al., 2005 Leew et al., 2009

1 ADHDVandenBerg, 2001

1 Developmental DelaysReichow et al., 2009

Weighted Vest

Diagnoses & Interventions

1 Music TherapyKim et al., 2008

1 Picture Activity SchedulesBryan & Gast, 2000

1 Hug MachineEdelson, et al., 1998

1 Therapy Ball ChairsBagatell et al., 2010

Therapy as Usual (all children with autism)

Inclusion Criteria• Confirmed physician diagnosis• Between 2 and 13 years old• Korean Childhood Autism Rating Scale• Problematic behaviors interfering with

ADLs• 65 or above on Conners’ Teacher Rating

Scale

Exclusion Criteria

• Diagnoses not confirmed by physicians

• Over 13 and younger than 2 years old

• Current therapy (OT, PT, SLP) in 9

studies

• Co-morbid diagnoses

Sample Sizes• Range: 1 child to 12 children

• Average: 6 children per study

Weighted Vest Intervention: ABA Withdrawal Design

• Initial baseline phases (A)– Classroom fine-motor activity

• Intervention phases (B)– Classroom fine-motor activity– 2 studies: Vests worn six 20-30 minute sessions– 1 study: Vests worn 2 hrs. per day, 3x/wk for 12 wks– 1 study: Vests worn 45 minutes during 14 sessions

• Withdrawal phases (A)– Classroom fine-motor activity– Removal of vests

Weighted Vest Intervention:ABC Withdrawal Design

• Baseline phase (A):– Classroom fine-motor activity

• Experimental phase (B):– Vests worn without weight 20-30 mins./day for 2

wks

• Experimental phase (C):– Vests worn with weight 20-30 mins./day for 2 wks

Treatment as Usual: Hug Machine • Two 20 min. sessions/wk. for 6 wks.

• Experimental group: – Lie in Hug Machine – Lever provided deep pressure

• Control group:– Lie in the Hug Machine – Lever disengaged

Treatment as Usual: Therapy Ball Chairs• Baseline phase:

– 15 minute classroom “Circle Time” – No therapy ball chairs

• Intervention phase: – Utilized therapy ball chairs during “Circle Time”

Treatment as Usual:Picture Activity Schedules

• Baseline phase:– Classroom activity 45 mins./day for 5 days– No picture activity schedule

• Intervention phase:– Picture activity books– 4 step activity

Treatment as Usual: Music Therapy

• Baseline phase:– Observed engagement during normal play – 30 mins./day for 12 weeks

• Intervention phase:– Observed during normal play incorporating music– 30 mins./day for 12 weeks

Outcome Measures• Data sheets (10 studies)

• Data collection:– Videotaped recordings – Researcher observations– Conner’s Parent Rating Scale– Parenting Morale Index– Pre-tests and post-tests

• Pervasive Developmental Disorder Behavior Inventory-C

Data Analysis• MANOVA

• Repeated measures ANOVA

• 2-standard deviation

• Celeration line approach – Predicted an increase or decrease in on-task

behavior

Methodological Quality of Studies

• Natural environments– Classroom – Home

• Randomization in 5 studies

• Blinding in 5 studies

Controlling for Threats to Validity• Same diagnoses

• Did not include scores of 3 children who dropped out

• Served as own control

• Inter-rater reliability

• Controlled for maturation by conducting the studies within weeks

Limitations• Small number of participants

• Only male participants in four studies

• Only one facility when recruiting participants

• Unequal groups in 4 studies:– Group numbers– 1 child had previous experiences with weighted vests– Experimental group rated higher on the Tension and

Anxiety Scale than control group

Limitations• Poorly defined procedures:

– Did not state the frequency, duration, or intensity of OT

• Undisclosed treatment environment

• No means of controlling environmental distractions– Disruptive classmates – Loud noises

• No randomization in group assignments in 5 studies

Limitations• No experimenter blinding in 5 studies

• No psychometric properties of tests were disclosed in 5 studies

• Hawthorne effect – Children knew they were being observed

Results: Treatment as Usual• Hug Machine:

– Experimental group lower tension levels on the Tension Scale than control group • t(10)= 3.124, p<.05

– Lower on Anxiety Scale than the control group • t(10)=1.959, p<10

• Therapy Ball Chairs:– Positive effects during “Circle Time”– Decreased number of minutes spent out of chair– No p values given

Results: Treatment as Usual• Picture Activity Schedule:

– Children remained on-task and on-schedule when using the books

– No p values given

• Music therapy:– Increased eye contact (p<0.0001). – Medium effect on on-task behavior (d=.63)

Results: Weighted Vests• ADHD:

– Significant change (p<.05) from baseline to intervention

– Increase in on-task behavior (18% - 25%)

• Developmental Delays:– No improvement in on-task behavior– Greater incidences of problematic behavior– No p values

Results: Weighted Vests• PDD:

– 1st study• Decrease in number of distractions • Increase in focused attention• No p values

– 2nd study (PDD & autism)• No increase in on-task behavior• No p values

Results: Weighted Vests • Autism:

– 1st study• No overall improvement in on-task behavior• Slight increase in on-task behavior in one child, but not

maintained• No p values

– 2nd study• No increase in on-task behavior• No p values

Discussion• Evidence suggests that weighted vests

are not a more effective intervention than OT as usual for increasing on-task behavior in children with Developmental Delays and ASD (autism, PDD)

Discussion• Weighted vests appeared to temporarily

improve on-task behavior in one child with PDD– Long term effects not evaluated

– Child received OT throughout the study

– Unable to determine whether the results were contributed to the vests or from OT

Discussion• Weighted vests appeared to have

significant effects on children with ADHD

• Only included 4 children– Convenience sampling recruitment method– Long term effects not evaluated

Discussion• OT as usual is noted to be a more effective

method for promoting on-task behavior in children with ASD

• Therapy ball chairs– Positive effects on in-seat and on-task behavior

• Music therapy – Effective intervention

Discussion• Hug Machine

– Deep pressure can contribute to an increase in on-task behavior

– Extensive measures to control for threats

• Picture activity schedules – Children’s performance increased by 100%

Conclusion• Efficacy of weighted vests depends on

the child and his or her diagnosis

• OT as usual appears to be a more reliable option for improving on-task behavior in children with ASD

Implications for OT Practice• Weighted vests may provide short-term

calming effects on children with ADHD, but long-term effects have not been evaluated

• OTs should not generalize the results to adults and diagnoses outside of the study

• OTs who use weighted vests must proceed with caution until further evidence can be established

Implications for Future Research

• Replicating in other contexts• Long term effects• Longer intervention period• Examining other protocols• Larger sample sizes • Boys and girls• Increasing amounts of weight in vests

References• Bagatell, N., Mirigliani, G., Patterson, C., Reyes, Y., & Test, L. (2010). Effectiveness of therapy ball chairs on classroom participation in

children with autism spectrum disorders. American Journal of Occupational Therapy, 64, 895–903.• Bryan, L., & Gast, D. (2000). Teaching on-task and on-schedule behaviors to high-functioning children with autism via picture activity

schedules. Journal of Autism and Developmental Disorders, 30(6), 553-567.• Edelson, S., Edelson, M., Kerr, D., & Grandin, T. (1999). Behavioral and physiological effects of deep pressure on children with autism: a

pilot study evaluating the efficacy of grandin's hug machine. The American Journal of Occupational Therapy, 53(2), 145-152.• Fertel-Daly, D., Bedell, G., & Hinojosa, J. (2001). Effects of a weighted vest on attention to task and self-stimulatory behaviors in

preschoolers with pervasive developmental disorders. The American Journal of Occupational Therapy, 55(6), 629-640. Retrieved from http://www1.aota.org/ajot/index.asp

• Hodgetts, S., Magill-Evans, J., & Misiaszek, J. (2010). Weighted vests, stereotyped behaviors and arousal in children with autism. Journal of Autism and Developmental Disorders, 41, 805-814.

• Kane, A., Luiselli, J., Dearborn, S., & Young, N. (2004). Wearing a weighted vest as intervention for children with autism/pervasive developmental disorder. The Scientific Review of Mental Health Practice, 3(2), 19-24.

• Kim, J., Wigram, T., & Gold, C. (2008). The effects of improvisational music therapy on joint attention behaviors in autistic children: a randomized controlled study. Journal of Autism and Developmental Disorders, 38, 1758-1766.

• Krebs, M, McDaniel, M, & Neely, R. (2011). The effects of peer training on the social interactions of children with autism spectrum disorders. Education, 131(2), 393-403.

• Leew, S., Stein, N., & Gibbard, B. (2010). Weighted vests' effect on social attention for toddlers with autism spectrum disorders. Canadian Journal of Occupational Therapy, 77(2), 113-124.

• Moss, J, & Howlin, P. (2009). Autism spectrum disorders in genetic syndromes: implications for diagnosis, intervention and understanding the wider autism spectrum disorder population. Journal of Intellectual Disability Research, 53(10), 852-873.

• Reichow, B., Barton, E., Good, L., & Wolery, M. (2009). Brief report: effects of pressure vest usage on engagement and problem behaviors of a young child with developmental delays. Journal of Autism and Developmental Disorder, 39, 1218-1221.

• Sansosti, F. (2010). Teaching social skills to children with autism spectrum disorders using tiers of support: a guide for school-based professionals. Psychology in the Schools, 47(3), 257-278.

• VandenBerg, N. (2001). The use of a weighted vest to increase on-task behavior in children with attention difficulties. The American Journal of Occupational Therapy, 55(6), 621-628. Retrieved from http://www1.aota.org/ajot/index.asp

• Watling, R. L., & Dietz, J. (2007). Immediate effect of Ayres’s sensory integration–based occupational therapy intervention on children with autism spectrum disorders. American Journal of Occupational Therapy, 61, 574–583.

Thank You!