The minimal clinically important difference (MCID) is relevant in the estimation of improvement in a patient outcome.
To determine the MCID on the Aberrant Behaviour Checklist–Irritability (ABC-I), widely used to measure the effects of intervention for aggressive challenging behaviour in people with intellectual disabilities.
Method and Procedures
We utilised distribution and anchor based methods to estimate the ABC-I MCID. We extracted data from 15 randomised controlled trials (RCTs) for meta-analysis. We conducted three online workshops with family carers and professionals to consider meaningful change in case vignettes of increasing severity of aggressive challenging behaviour.
Outcomes and Results
We did not find overlap in the range of values between the two approaches. The meta-analysis indicated a range of MCID on the ABC-I (0.05, 4.94) whilst the anchor-based estimation indicated a larger change (6.6, 16.6).
Conclusions and Implications
The MCID is essential in interpreting the results from intervention studies. The present work was undertaken as part of a wider programme on the development and testing of a psychosocial intervention for aggressive challenging behaviour, and it is of interest to researchers in justifying how they choose and determine the MCID on the outcome of interest.
Bibliographical noteFunding Information:
The PETAL programme is funded by the National Institute for Health Research (NIHR) [PGfAR NIHR200120]. The views expressed within the manuscript are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.
© 2022 Elsevier Ltd
- Intellectual Disabilities
- Clinical trials
- Aggressive challenging behaviour