A pragmatic mixed-methods review of changing “case-complexity” of referrals to an intensive support service

“Case-complexity” is a widely used but under-explored concept across health and social care. A region’s Intensive Support Teams (ISTs) had been reporting an increase in “case-complexity”, but had not tested this hypothesis against data. This study aims to investigate this question through a pragmatic mixed-methods approach as part of a wider service evaluation.,Health of the Nation Outcome Scales for People with Learning Disabilities (HoNOS-LD) scores were used (n = 1,766) to estimate average “case-complexity” of referrals over an eight-year sample period. Two focus groups for IST staff (n = 18) explored why “case-complexity” appears to be increasing. Participant perspectives were subjected to thematic analysis.,Average HoNOS-LD scores have steadily increased over the sample period, suggestive of increasing “case-complexity”. Focus groups identified three broad themes to potentially explain the increased complexity: effects of Transforming Care; people’s changing and unchanging support systems; and issues related to mild and borderline intellectual disability. Many perspectives are grounded in or supported by evidence.,Implications and limitations of findings are discussed, including areas for further consideration and research. The well-designed “short-cut” is promoted as a strategy for busy professionals in need of practice-based evidence but with limited research time and resources.,The findings and discussion will be of value to anyone involved in the design, commissioning and delivery of mental health and challenging behaviour services to people with intellectual and developmental disabilities (IDD) under Transforming Care. Study methodology is easily replicable to build broader picture about “case-complexity” among UK’s IDD population.