Development and validation of a new suicidality assessment tool with autistic adults Dr. Sarah Cassidy @MHAutism
Background • High rates of suicidality in autistic people (Kirby et al. 2019; Cassidy et al. 2018a; Hirvikoski et al. 2016; Cassidy et al. 2014) • BUT no validated suicidality assessment tool available for autistic adults (Cassidy et al. 2018) • MHAutism project aimed to develop a tool to better identify suicidal thoughts and behaviours, in partnership with autistic adults, for use in research
Stage 1 • No tool with evidence of validity yet been used in suicidality research with autistic adults • SBQ-R potentially useful for research
Stage 2: Candidate Tool Evaluation • What is the evidence regarding the appropriateness and measurement properties of the SBQ-R in autistic adults? • Study a: Online survey to gather large sample of autistic and general population adults SBQ-R to compare the structure between groups • Study b+c: Interviews with a subsample of survey participants (n=15) and Delphi survey (n=251) to explore how autistic adults interpret the items + inform adaptations
SBQ-R Hypothesised Structure 1. Lifetime experience of suicidal ideation and/or attempt. 2. frequency of suicidal ideation over the past twelve months. 3. Threat of a suicide attempt – communication of suicide intent to others. 4. Self-reported likelihood of suicidal behavior in the future. Cassidy, S. A., Bradley, L., Bowen, E., Wigham, S., & Rodgers, J. (2018). Measurement properties of tools used to assess suicidality in autistic and general population adults: A systematic review. Clinical Psychology Review.
Stage 2: Measurement Invariance • Online survey of 188 autistic and 183 non-autistic adults completing the SBQ-R matched on age and gender: *p < .05. RMSEA = Root-Mean-Square Error of Approximation. CFI = Comparative Fit Index. TLI = Tucker-Lewis Index. 1Significant degradation in fit is seen after this model.
Stage 2: Content Validity “Something missing” between a brief passing thought and plan. “Am I really bad?” “Does not capture the intensity of the thought or the length or time” “Who would you tell?” But an important question! “It’s a future question and you don’t know what’s going to happen” Important, but “impossible to answer”
Stage 2: Summary • Autistic people interpret the items of the SBQ-R differently to non-autistic adults • Items tapping into social communication and isolation, and abstract future thinking are particularly challenging for autistic people to answer • Scores on the SBQ-R cannot be compared between autistic and non-autistic people • Items need to be adapted in partnership with autistic people
Stage 3: Adaption and validation • Cognitive Interviews with the same 15 autistic adults to co-produce adaptations • Delphi Survey with 251 autistic adults to obtain feedback on adapted tool • Validation Survey with 289 autistic and 258 non-autistic adults to explore measurement properties
Stage 3: Results Added in a stage between a brief passing thought and a plan Simplified language Follow up Q’s: impulsivity, plans, and access to means Full range of frequency of suicidal thoughts captured in the past year Capture perseverative thoughts Made question a little less abstract. ~50% find the visual useful. Include communication of intent and past attempts. Simplified response options. Follow up Qs: Who did you tell? Why have you never told anyone?
N-Autistic (n=119) Stage 3: EFA sample 1 Autistic (n=144) 1. Lifetime experience of suicidal ideation and/or attempt. .8 .889 2. frequency of suicidal ideation over the past twelve months. .635 .676 3. Perseveration of suicidal thoughts. .793 .838 4. Likelihood of acting on suicidal thoughts. .776 .782 5. Communication of suicidal thoughts and behaviours. .798 .797 .857 .8
Stage 3: Invariance in sample 2 • 139 non-autistic and 145 autistic adults matched on age and gender.
Stage 3: Invariance in sample 2 • Excluding non-invariant item 2, evidence for scalar invariance between autistic and non-autistic adults SBQ-ASC scores.
Autistic Adults: Construct Validity + Test Re-Test Reliability • SBQ-ASC T1 scores significantly correlated to T2 scores 2-weeks later: • (n = 137, r = .815, p < .001)
Autistic Adults: Sensitivity and Specificity N = 289, AUC = .789 95% CI .73-.847, p<.001
Discussion • In partnership with autistic adults we have adapted a widely used tool, the SBQ-R to better capture suicidality in this group • Evidence in support of a range of measurement properties • The SBQ-ASC can be used to compare scores between autistic and non-autistic adults (using invariant items) • The SBQ-ASC is validated for use in research • Open source research tool Sarah.Cassidy@Nottingham.ac.uk
Thanks to … University of Nottingham: Heather Cogger-Ward Coventry University:Dr. Louise Bradley, Dr. Rebecca Shaw. Newcastle University: Prof. Jacqui Rodgers, Dr. Magdalena Glod. University of Worcester:Prof. Erica Bowen. Autism Research Centre, University of Cambridge: Prof. Simon Baron-Cohen, Paula Smith. Autistic Steering Group and Attendees of 1stMHAutism workshop Everyone who took part! Sarah.Cassidy@Nottingham.ac.uk @MHAutism