Rationale, aims and objectives The concept of patient or case complexity
is relevant – and widely used – at all levels and stages of mental
health service provision, but there have been few methodologically
robust attempts to define this term. This study aimed to establish a
consensus on factors contributing to patient complexity in adult
psychological services using Delphi Methodology. Method Applied
psychologists in a single urban/suburban UK National Health Service
setting took part in a three-round modified Delphi study. Twenty-eight
respondents in round one gave qualitative data on factors they
considered when assessing complexity, which was subject to thematic
analysis. Twenty-five respondents in round two rated how
central/peripheral each theme was to their judgement using Likert
scales. In a third round, twenty respondents addressed discrepancies and
possible utilities of the emerging framework. Results Thirteen factors
contributing to patient/case complexity (Active Severe/Enduring Mental
Health, Current Coping/Functioning, Engagement, Forensic History,
Iatrogenic Factors, Interpersonal Functioning, Neuro-Cognitive
Functioning, Physical Health, Problematic Substance Use, Risk,
Severity/Chronicity of Presenting Problems, Systemic and Socio-Economic
Factors and Trauma) were identified with a high degree of consensus. All
were rated as central to complexity. Conclusions We conclude that
applied psychologists do have a shared understanding of complexity and
make recommendations for further research validating, developing and
applying this empirically derived framework. Keywords: psychological,
complexity, definition, operationalising, framework development,
clinical judgement