The Effect of Play-Based Occupational Therapy on Playfulness and Social Play of Children with Autism Spectrum Disorder: A Systematic Review

Figures & data

Table A1. Study particulars.

References	Location	Diagnosis, age range	Demographics: gender; level of support; ethnicity/race	Sample size, group descriptors
Anu et al. (2019)	India	ASD (diagnosis: DSM-V)	−35 males, 7 females in control	42 participants in total (n = 42) −experimental group (n = 21) −control group (n = 21) −no information about prior treatment
		3–7 years	−2-word verbalization, productive interaction
		mean: 4.3 years	−medium to high support
Chen et al. (2022)	Taiwan	ASD (diagnosis: DSM-V)	−7 males	7 participants in total (n = 7) −4 received rehabilitation prior to intervention −only experimental group, no control
		6–7 years	−1st Grade, IQ of 85 or above
		mean: 78.1 months	−low support
Davidson and Stagnitti (2021)	Australia	ASD (diagnosis: DSM-V)	−5 males; 1 female	6 participants in total (n = 6) −one parent per child participated in the study (forming a dyad) −only experimental group, no control
		2.5–5.9 years	−developmental level: 12–18 months
		Mean: 3.8 years	−one meaningful word/focused attention
			−medium to high support
Dionne and Martini (2011)	United Sates of America	ASD (diagnosis: CARS)	−1 male	1 participant in total (n = 1) −received prior occupational therapy
		3.6-year-old boy	−single word utterances, use of Picture Exchange Communication System (PECS®) to
		diagnosed at 2.5 years.	communicate −high support
Doernberg et al. (2021)	Australia	ASD-HF (diagnosis: ADOS)	−22 males; 3 females	25 participants in total (n = 25) −experimental group (n = 18) −control group (n = 7) −no information about prior treatment
		6–9 years	−IQ 85 and above; mainstream schooling
			−low support
			−10 Caucasian; 2 African American; 1 Asian; 3 Other; 9 not reported
Fabrizi (2015)	United States of America	ASD (diagnosis:	−6 males; 4 females	10 participants with ASD (n = 10) −ASD participants paired with caregiver (dyad) −only experimental group, no control
		ADOS) 2–3 years	−high support
			−4 Hispanic; 3 Caucasian; 2 African American; 1 Asian
Henning et al. (2016)	Australia	ASD (diagnosis: DSM-V)	−5 males	5 participants in total (n = 5)
		4–11 years	−IQ of 70 and above for those with ASD	−ASD participants paired with typically developing peers (dyad)
		Mean: 7.8 years	−low support	−no information about prior treatment
			−4 Caucasian; 1 Asian in ASD group	−only experimental group, no control
Kent et al. (2020)	Australia	ASD (diagnosis: DSM-V)	−57 males	57 participants in total (n = 57)
		6–12 years	−only mainstream schooling included	−experimental group (n = 30)
		Included ADHD and anxiety;	−low support	−control group (n = 27)
		Excluded ID
Legoff and Sherman (2006)	United States of America	ASD (DSM-IV)	−96 males; 21 females	117 participants in total (n = 117)
		Mean ages-	−all were enrolled ay mainstream schools	−experimental group (n = 60)
		Experimental group: 9.3 years	−low support	−control group (n = 57)
		Control: 10.1 years
Marwick et al. (2022)	United Kingdom	ASD (diagnosis: DSM-V)	−6 males; 1 female	7 participants in total (n = 7)
		5–8 years	−medium to high support	−no information regarding prior intervention
		2 participants: moderate learning	−all enrolled in learners with special education needs (LSEN) schools	−only experimental group, no control
		difficulties
Owens et al. (2008)	United Kingdom	ASD (diagnosis: DSM-IV)	−31 males	31 participants in total (n = 31)
		6–11 years	−IQ of 70 and above	−experimental group (n = 16)
			−speaking in appropriate phrases	−control group (n = 16)
			−low support	−prior rehabilitation
Wolfberg et al. (2015)	United States of America	ASD (diagnosis: ADOS)	−41 males; 7 females	48 participants in total (n = 48)
		5–10 years	−ranged from pre-verbal to fluent speech	−experimental group (n = 9)
			−medium to low support	−control group (n = 39)
				−no information regarding prior intervention

Table A2. Intervention particulars.

Reference	Study Aims	Intervention Framework	Strategies used	Materials used	Duration and setting	Social Play and Playfulness Outcome Measures
Anu et al. (2019)	Improve social competence through pretend play	Learn to Play programme	Group & individual therapy Home play Imitation of play sequences Guided & free play	Familiar play objects Visuals Video-modeling	6-month intervention 80–100 sessions 1 30-minute individual session & 1 30-minute group session per week Clinic, school	−ChIPPA −Caregiver-rated goals −SIPDC
Chen et al. (2022)	Determine the efficacy of a play-based social skills programme	Play-based social skills training programme	Group therapy Imitation of play sequences Social skills games Homework assignments Role Play situations Adult-directed play	Familiar play objects Visuals Social skills scripts	3-month intervention 10–12 sessions 1 60-minute group session per week Clinic, school	−Video Coding −GAS goals −VABS-3
Davidson and Stagnitti (2021)	Analyze the effectiveness of the Learn to Play Process	Learn to Play programme	Group & individual therapy Home play Imitation of play sequences Guided & free play	Familiar play objects Visuals Video-modeling	6-month intervention 24 sessions 1 30-minute individual session & 1 30-minute group session per week School	−For 3 years or over: ChIPPA; −younger child: assessed using (PPE-DC) −videos of sessions analyzed using PPE-DC) −caregiver-rated goals
Dionne and Martini (2011)	To determine effectiveness of Floor Time® Play	Floor Time® Play programme	Individual therapy Home play Imitation of play sequences Guided play	Familiar play objects Visuals Social skills scripts	2-month intervention 35 sessions 4 45-minute individual sessions per week Clinic	−CARS −Sensory Profile −FAES −CoC −Video analysis
Doernberg et al.(2021)	To determine the efficacy of an adapted pretend play programme (for high-functioning ASD)	Adaption of a preexisting pretend play programme which was originally developed for typically developing children	Individual therapy Home play Imitation of play sequences Guided & free play	Familiar play objects Visuals	5-week intervention 5 sessions 1 20-minute individual session per week School	−The Affect in Play Scale (APS) −KAIR
Fabrizi (2015)	Analyze the effectiveness of an aquatic play group to improve playfulness and social play of children with ASD	The Test of Playfulness (ToP) items were used to create a model for play-based groups in the aquatic environment	Group therapy Home play Imitation of play sequences Guided & free play	Familiar aquatic toys Visuals Video-modeling	2-month intervention 9 sessions 1 40-minute group session per week Community pool	−ToP −TOES: caregiver rated
Henning et al. (2016)	Determine the feasibility and effectiveness of a play-based intervention to address the social play skills	Adapted design of a previous play-based intervention for improving the social play skills of children with ADHD	Individual therapy Home play Imitation of play sequences Guided play	Familiar play objects Visuals Social skills scripts	7-week intervention 8 sessions 1 60-minute individual session per week Clinic, School	−ToP −CCBRS-P −CCC-2
Kent et al. (2020)	Improve social play of children with ASD through peer-mediated intervention	The Ultimate Guide to Play, Learning and friendship programme (PLF)	Individual therapy Home play Imitation of play sequences Role Play situations Guided play	Familiar play objects Visuals Video-modeling Social skills scripts	3-month intervention 10 sessions 2 30-minute individual sessions per week Clinic, school	−ToP −caregiver-rated goals −PRQ -Piers-Harris
Legoff and Sherman (2006)	Determine the effectiveness of LEGO® Play to improve social play of children with ASD (high functioning)	LEGO® Play programme	Group Therapy Imitation of play sequences Modelling Adult-directed play	Familiar LEGO® blocks Visuals Social skills scripts	36-month retrospective Intervention; number of sessions not provided 1 90-minute group session per week School	−VABS-3 −GARS-SI
Marwick et al. (2022)	Encouraging playfulness, social and joint play with use of playboxes	The Playboxes Joint Play Approach	Group & individual therapy Home play Imitation of play sequences Peer involvement Fantasy and Role Play Guided & free play	Familiar play objects Novel play objects Visuals Video-modeling Fantasy play scripts	3-month intervention 10 sessions 1 40-minute individual session & 1 40-minute group session per week School	−ToPP −SPT
Owens et al. (2008)	Determine the effectiveness of LEGO® Play to improve social play of children with ASD (high functioning)	LEGO® Play programme	Group Therapy Imitation of play sequences Adult-directed play	Familiar LEGO® blocks Visuals Social skills scripts	5-month intervention; number of sessions not provided 1 60-minute group session per week School	−VABS-3 −GARS-SI
Wolfberg et al. (2015)	Determine the effect of the Integrated Play Groups (IPG) Approach on the social play of children with ASD	Integrated Play Groups Approach	Group Therapy Imitation of play sequences Scaffolding Modelling Adut-directed play	Familiar play objects Visuals Social skills scripts	3-month intervention; number of sessions not provided 2 60-minute group sessions per week School	−Video analysis −IPG Approach Assessments (found in IPG guidelines)

Key for intervention particulars table

ChIPPA: Child Initiated Pretend Play Assessment; FAES: Functional Emotional Assessment Scale

CoC: Closed Circles of Communication; PPE-DC: Pretend Play Enjoyment Developmental Checklist

K-CPT2: Conners Kiddie Continuous Performance Test-Second Edition; CCBRS-P: Conners’ Comprehensive Behaviour Rating Scales–Parent

CCC-2: Children’s Communication Checklist; WISC–III: Wechsler Intelligence Scale for Children–Third Edition

KAI-R: The Kusche Affective Inventory Revised (KAIR); HCSBS: Home and Community Social Behaviour Scales

WPPSI–R: Wechsler Preschool and Primary Scale of Intelligence–Revised; CDDC: Communication Deall Developmental Checklist

SIPDC: Symbolic and imaginative play developmental checklist; VABS: Vineland Adaptive Behaviour Scales

GARS-SI: Gilliam Autism Rating Scale; ToP: Test of Playfulness

TOES: Test of Environmental Supportiveness; ToPP: Test of Pretend Play

GAS: Goal Attainment Scales; SPT: Symbolic Play Test

PRQ: Parent Relationship Questionnaire

Table A3. Risk of Bias.

		JBI Checklist results, according to Yes (Y) and No (N) answers
Reference	Study Design	1	2	3	4	5	6	7	8	9	10	11	12	13	Analysis of Risk of Bias (ROB) with reasons	Evidence level
Anu et al. (2019)	Quasi Experimental	Y	Y	Y	Y	Y	Y	Y	Y	Y					LROB: 9/9 (100%) −very low risk, all limitations mentioned in study	II
Chen et al. (2022)	Quasi Experimental	Y	Y	UN	N	Y	Y	N/A	Y	Y					MROB: 5/8 (62.5%) −no control; unclear about prior treatment	III
Davidson and Stagnitti (2021)	Quasi Experimental	Y	Y	Y	N	N	UN	Y	Y	Y					MROB: 6/9 (66.6%) −no control; no multiple measures of outcome	III
Dionne and Martini (2011)	Cross Sectional	N	Y	Y	Y	N	N	Y	Y						MROB: 5/8 (62.5%) −criteria unclear; no follow up;	IV
Doernberg et al. (2021)	Quasi Experimental	Y	Y	Y	Y	Y	Y	Y	Y	Y					LROB: 9/9 (100%) −very low risk; all limitations mentioned by study	II
Fabrizi (2015)	Quasi Experimental	Y	Y	UN	N	Y	Y	Y	Y	Y					LROB: 7/9 (77.7%) −unclear about previous treatment; no control	III
Henning et al. (2016)	Quasi Experimental	Y	Y	UN	N	Y	Y	Y	Y	Y					LROB: 7/9 (77.7%) −unclear about previous treatment; no control	III
Kent et al. (2021)	RCT	Y	UN	Y	UN	Y	Y	Y	Y	Y	Y	Y	Y	Y	LROB: 11/13 (84.6%) −providers of treatment not blinded	I
Legoff and Sherman (2006)	Quasi Experimental	Y	Y	Y	Y	Y	Y	Y	Y	Y					LROB: 9/9 (100%) −very low risk, all limitations mentioned in study	II
Marwick et al. (2022)	Quasi Experimental	Y	Y	Y	N	Y	UN	Y	Y	UN					MROB: 6/9 (66.6%) −no control group; unclear about follow up	II
Owens et al. (2008)	RCT	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	Y	Y	LROB: 12/13 (92.3%) −providers of treatment not blinded to treatment	I
Wolfberg et al. (2015)	Quasi Experimental	Y	Y	Y	N	Y	Y	Y	Y	Y					LROB: 8/9 (88.8%) −no control group	II

Key for JBI Checklist evaluation questions in relation to study design

	Quasi-Experimental study design	Randomised Control Trial study design	Cross Sectional study design
1	Is it clear in the study what is the “cause” and the “effect”?	Was true randomization used for assignment of participants to treatment groups?	Were the criteria for inclusion in the sample clearly defined?
2	Were the participants included in any comparisons similar?	Was allocation to treatment groups concealed?	Were the study subjects and the setting described in detail?
3	Were the participants included in any comparisons receiving similar treatment?	Were treatment groups similar at the baseline?	Was the exposure measured in a valid and reliable way?
4	Was there a control group?	Were participants blind to treatment assignment?	Were objective, standard criteria used for measurement of the condition?
5	Were there multiple measurements of the outcome both pre- and post-intervention?	Were those delivering treatment blind to treatment assignment?	Were confounding factors identified?
6	Was follow up complete/were differences between groups in terms follow up analysed?	Were outcomes assessors blind to treatment assignment?	Were strategies to deal with confounding factors stated?
7	Were the outcomes of participants included in any comparisons measured in the same way?	Were treatment groups treated identically other than the intervention of interest?	Were the outcomes measured in a valid and reliable way?
8	Were outcomes measured in a reliable way?	Was follow up complete/were differences between groups in terms follow up analysed?	Was appropriate statistical analysis used?
9	Was appropriate statistical analysis used?	Were participants analyzed in the groups to which they were randomized?
10		Were outcomes measured in the same way for treatment groups?
11		Were outcomes measured in a reliable way?
12		Was appropriate statistical analysis used?
13		Was the trial design appropriate, and any deviations from the standard RCT design (individual randomization, parallel groups) accounted for?

LROB: Low Risk of Bias.

MROB: Moderate Risk of Bias.

HROB: High Risk of Bias.

N/A: Not Applicable.

UN: Unclear.

Y: Yes.

N: No.

Table A4. Quality of Intervention reporting (Tidier Checklist).

Study, Year	Name	Rationale	Materials	Providers	Delivery	Location	Period	Modifications	Feasibility: planned	Feasibility: Actual	Score	Percentage
Anu et al. (2019)	1	1	1	1	1	1	1	0	1	1	9	90%
Chen et al. (2022)	1	1	0	1	1	1	1	0	1	1	8	80%
Davidson and Stagnitti (2021)	1	1	1	1	1	1	1	1	1	1	10	100%
Dionne and Martini (2011)	1	1	0	1	1	1	1	1	0	0	8	70%
Doernberg et al. (2021)	1	1	1	1	1	1	1	1	1	0	9	90%
Fabrizi (2015)	1	1	1	1	1	1	1	0	1	0	8	80%
Henning et al. (2016)	1	1	0	1	1	1	1	0	1	0	7	70%
Kent et al. (2021)	1	1	1	1	1	1	1	0	1	1	9	90%
Legoff and Sherman (2006)	1	1	1	1	1	1	1	0	1	1	9	90%
Marwick et al. (2022)	1	1	1	1	1	1	1	1	1	1	10	100%
Owens et al. (2008)	1	1	1	1	1	1	1	0	1	0	8	80%
Wolfberg et al. (2015)	1	1	1	1	1	1	1	0	1	0	8	80%

Table A5. Effect of the interventions.

Reference	Key findings	Data correlating to key findings and mean adherence of participants	Overall effect of the intervention on social play and playfulness (post-intervention)	Long term outcomes for social play and playfulness (follow-up)
Anu et al. (2019)	Learn to Play is more effective than general social-skills training in improving social play, play skills and playfulness. Play-based occupational therapy can enhance the social play and playfulness of children with ASD.	19/21 participants in the experimental group showed indicators of typical play post-intervention. Significant improvement (p < 0.005, 95% CI: 0.000–0.069) in pretend and social play in experimental group. Mean adherence = 100%	Overall large effect Effect of pretend play in the experimental group (p < 0.005, 95% CI: 0.000–0.133) was more than that in the control group who participated in a general social skills programme.	No follow up assessments
Chen et al. (2022)	Intervention protocol to improve social play and social skills of children with ASD was developed. Play-based occupational therapy can enhance the social play and social skills of children with ASD. Video-analysis and GAS goals could be more effective in assessing long term effects of social play in children with ASD.	GAS goals relating to social play and social skills improved from a score of −2 to +2 post-intervention. VABS-3 scores showed improvement for two subdomains: written (r = 0.64) and receptive language (r = 0.59). These are large effect sizes but do not reflect social play. Mean adherence = 83%	Overall large effect Effect size for social play according to GAS goals and video analysis (r = 0.54) and effect size for positive affect during play (r = 0.63); (p < 0.05)	Follow up 1-month post-intervention Post-intervention scores were maintained but did not increase. Suggested that VABS-3 may not be sensitive enough to smaller changes in social play.
Davidson and Stagnitti (2021)	Learn to Play improved playfulness and play skills in children with ASD. Key techniques used by the therapist during play, such as repetition were reduced as the child’s playfulness improved.	Frequency of therapists’ repetition pre-intervention (n = 12). Frequency of therapists’ repetition post-intervention (n = 3). Frequency of participants’ play initiation pre-intervention (n = 11). Frequency of participants’ play initiation post-intervention (n = 16). Mean adherence = 84%	Overall large effect Social play and playfulness (play initiation, role play, substitution, positive affect) factors improved in the experimental group post-intervention (p < 0.005, 95% CI: 0.000–0.043).	No follow up assessments
Dionne and Martini (2011)	Floortime Play improved playfulness and social play in a child with ASD. Intensive (more frequent) therapy sessions over a shorter period improved social play more than less frequent sessions over a longer period.	Mean number of closed circles of communication (COCs) pre-intervention (n = 10). Mean number of CoCs post-intervention (n = 15.7). Mean adherence = 100%	Overall moderate effect Significant difference between CoC phase B and CoC in phase A. 2–5 successive sessions (22 in total) fell outside SD line= moderate significance.	No follow up assessments
Owens et al. (2008)	LEGO® Play improved social skills of children with high functioning ASD more so than the general language and social skills programme. LEGO® Play was found to only be suitable for verbal children with ASD.	11/16 children in the LEGO® Play group gave an enjoyment (positive affect) score of 10/10 on a ‘Parent satisfaction and Child enjoyment’ scale. 5/15 children in the Social Use of Language Programme (SULP) group gave 10/10 on this scale. No significant difference in the mean of these scores between the groups. Mean adherence not provided	Overall large effect Gillium Autism Rating Scale-Social Interaction subdomain (GARS-SI) pre-intervention scores (χ2 = 0.844, df = 2, p = 0.66) Gillium Autism Rating Scale-Social Interaction subdomain (GARS-SI) post-intervention scores (χ2 = 5.85, df = 2, p = 0.05)	No follow up assessments
Wolfberg et al. (2015)	Social and pretend play skills of participants improved due to the IPG intervention. However, playfulness factors were not influenced.	Social play domain score revealed significant main effects post-intervention (F = 7.66; p <0.01) Mean adherence not provided	Overall large effect Symbolic Play post-intervention (t = 6.59; p < 0.001; d = 0.96) Social Play post-intervention (t = 11.41; p<0.001; d = 1.66)	No follow up assessments

Key for effect of the interventions table

r: Pearson’s r. Value closer to -1 or 1indicates higher effect size. A positive value means both variables either increase or decrease together (Sullivan & Feinn, 2012).

d: Cohen’s d. 0.2 = small; 0.5 = medium; 0.8 or greater = large effect size (Sullivan & Feinn, 2012).

F: Cohen’s f. Estimates the proportion of variance in a sample. 0.10 = small; 0.25 = medium; 0.40 = large (Chen & Chen, 2010).

p: Relates to the null hypothesis of a study. Small p value = more likely to reject null hypothesis (Sullivan & Feinn, 2012).

t: t Statistic. To determine if there is a statistically significant difference between the means of two variables and whether to reject the null hypothesis (Chen & Chen, 2010).

PND: Percentage of non-overlapping data. PND < 50% = no observed effect; 50–70% = questionable; > 70% = effective (Henning et al., 2016).

ƞ_p² : Partial eta squared. Effect size used in studies using a repeated measures design. 0.01 = small; 0.06 = medium; 0.14 = large effect size (Richardson, 2011).

χ² : Chi-squared is to determine if a difference between observed data and expected data is due to chance, or due to a relationship between the variables being studied. Larger

chi-squared value is associated with smaller p value (McHugh, 2013).

CI: Confidence Interval. Indication of a population’s parameters. An estimate of how certain or uncertain the estimated difference between variables is (O’Brien & Yi, 2016).

df: Degrees of freedom. The number of independent pieces of information used to calculate a statistic of the sample. Small sample size = only a few independent pieces of information = small degree of freedom (Chen & Chen, 2010).

Figure B1. Diagram of the relationship between playfulness, play and social play.

Figure B2. Search Strings.*ti, ab, kw when searching Cochrane, refers to ‘title’, ‘abstract’ and ‘keyword’. For example, the articles’ title,abstract and keywords had to contain the word ‘autism’.

Figure B3. PRISMA flow diagram.

Figure B4. Forest plot of a study which improved social play.

Figure B5. Forest plots of a study which improved social play.

Figure B6. Forest Plot of a study which improved social play.

Figure B7. Forest Plot of a study which improved social play.

Figure B8. Forest plot of studies which improved playfulness and social play.

Figure B9. Principles of a successful play-based intervention for children with ASD.

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