Understanding Persistent Postconcussion and Post-traumatic Stress Symptomology in UK Police Officers Using Clustering and Classification Algorithms

BACKGROUND: Police officers frequently operate in dynamic, high-stress environments involving exposure to violence, accidents, and other critical incidents, placing them at heightened risk for traumatic brain injuries (TBIs), persistent postconcussion symptoms (PPCS), post-traumatic stress disorder (PTSD), and complex PTSD (C-PTSD). METHODS: A total of 573 currently serving frontline officers across England, Scotland, and Wales completed the online cross-sectional "Policing & Living Well" survey between January and August 2023. Participants self-reported PPCS using the Rivermead Postconcussion Symptoms Questionnaire and PTSD symptoms using the International Trauma Questionnaire. Unsupervised clustering (K-means) identified distinct symptom profiles, and random forest analysis determined key variables that most strongly distinguished the derived clusters. RESULTS: Two symptom-based clusters emerged, one with a low symptom load (n = 357) and a high symptom load group with elevated PPCS, PTSD, and C-PTSD symptoms (n = 216). Influential symptoms included the social impact of C-PTSD, feeling socially distant, feelings of failure, social-emotional disconnection, and worthlessness. The random forest model achieved 94% classification accuracy (precision = 0.93, recall = 0.91 for the high symptom load group). Membership in the high symptom load group was associated with single marital status, being ranked as a Uniform Inspector, and a history of single and multiple TBIs from motor vehicle accidents, falls, or assaults, particularly those involving loss of consciousness and occurring on active duty. CONCLUSIONS: UK police officers could be differentiated into low and high symptom burden groups. Social-emotional symptoms were the strongest contributors to symptom burden differentiation. Probable TBI history was also associated with the high symptom load group, highlighting the importance of considering both psychological and injury-exposure factors when assessing officer well-being.