Retrospective cohort study of acute behavioural disturbance in police use of force reports.

BACKGROUND:Acute Behavioural Disturbance (ABD) is a presentation of behavioural change which may conceal life-threatening illness. Concerns have been raised that it is used as a justification for deaths in custody and within the health and care system, but there is a lack of evidence exploring how the term ABD is applied in the UK. AIMS:to establish how UK police officers apply force in ABD compared to other presentations, examine outcome and fatality data, and identify regional variation and potential systemic issues in the application of the term ABD in a UK setting. METHOD:retrospective cohort study of 562,280 police use of force (UoF) reports (England and Wales, Apr 2020-Mar 2021). RESULTS:differences were identified in UoF location, co-existing contributors to UoF, justifications given, patient demographics, methods of restraint, and outcomes. Differences were also identified in UoF reports per capita and identification of ABD between police forces. CONCLUSION:while there are limitations to the data set and the paper is hypothesis-generating only, this study found evidence suggestive of variations in reporting practices between police forces, and evidence that identification of ABD appears to be associated with protective aims of UoF and more likely to result in a healthcare-focussed outcome. While the majority of ABD was identified in people perceived to be white men, some demographic criteria were associated with an increased relative risk that ABD was identified as a reason for UoF.