Cumulative risk effects for the development of behaviour difficulties in children and adolescents with special educational needs and disabilities

• A cumulative risk effect exists within a population of children and adolescents with SEND.
• Exposure to higher numbers of risk regardless of their nature, results in increased behaviour difficulties.
• Exposure to increasing risk has a disproportionate and detrimental impact on the display of behaviour difficulties.
• Consideration should be placed upon the impact of multiple risks when designing intervention to reduce behaviour difficulties.
• Interventions should be tailored towards individuals exposed to large numbers of risks.

Research has identified multiple risk factors for the development of behaviour difficulties. What have been less explored are the cumulative effects of exposure to multiple risks on behavioural outcomes, with no study specifically investigating these effects within a population of young people with special educational needs and disabilities (SEND). Furthermore, it is unclear whether a threshold or linear risk model better fits the data for this population. The sample included 2660 children and 1628 adolescents with SEND. Risk factors associated with increases in behaviour difficulties over an 18-month period were summed to create a cumulative risk score, with this explanatory variable being added into a multi-level model. A quadratic term was then added to test the threshold model. There was evidence of a cumulative risk effect, suggesting that exposure to higher numbers of risk factors, regardless of their exact nature, resulted in increased behaviour difficulties. The relationship between risk and behaviour difficulties was non-linear, with exposure to increasing risk having a disproportionate and detrimental impact on behaviour difficulties in child and adolescent models. Interventions aimed at reducing behaviour difficulties need to consider the impact of multiple risk variables. Tailoring interventions towards those exposed to large numbers of risks would be advantageous.