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Society faces significant challenges caring for people with urgent mental health needs. General hospitals are well equipped for dealing with medical emergencies, but much less skilled in managing mental health problems. Ambulance and policing staff frequently encounter such individuals, with transport to Emergency Department often the only care pathway. In the UK, no evidence existed on general hospital patterns prior to suicide, or on outcomes for pre-hospital mental health emergencies. This thesis contains five papers, consisting of four research studies and one protocol. Three papers report innovative quantitative approaches using linked datasets. Using 30 years of Scottish hospital data, I showed that 10,907 people who died by suicide with hospital records were 3.1 times more frequently last discharged from general, not psychiatric hospital; 24% within three months of last discharge, of whom 58% were from general hospital. Using national deaths registrations, I reported that cohorts of men born around 1965-70 had been at greater vulnerability to suicide in the 1990s, with stark differences in suicide rates between Scotland, and England & Wales. Analyses of data on unscheduled care revealed that within one year of paramedic attendances for 6,802 people with 'psychiatric emergency', 297 had died, 35% of whom were deaths by suicide. Paramedics were in contact with 8% of people in the year before they died by suicide. Police officers encountering people with mental health concerns have no formal means of vulnerability assessment to support triaging. A review of the evidence found no consensus definition for vulnerability or means of assessing vulnerability, a lack of congruence in terminology across policing and health, and a likely barrier to accessing services. Finally, a protocol was published outlining methods for an analysis of childhood adversity as seen in national hospital datasets. This thesis provides evidence to support redesign of more integrated services, highlights areas for suicide prevention, and closes with an impact generation exemplar.

Background: Changing service demands require United Kingdom ambulance services to redefine their role and response strategies, in order to reduce unnecessary Emergency Department attendances. Treat and Refer guidelines have been developed with this aim in mind. However, these guidelines have been developed in the absence of reliable evidence or guiding mid-range theory. This has resulted in inconsistencies in clinical practice. One condition frequently included in Treat and Refer guidelines is hypoglycaemia. Therefore this thesis aimed to investigate prehospital hypoglycaemic emergencies in order to develop an evidence base for future interventions and guideline development. Research approach: A pragmatic and inductive applied health services research approach was employed. Multiple methods were used in a sequential explanatory design. Three linked studies were undertaken with the results of previous studies informing the development of the next. Study one: A scoping review of prehospital treatment of hypoglycaemic events. Aims: i) To describe the demographics of the patient population requiring ambulance service assistance for hypoglycaemic emergencies; ii) To determine the extent to which post-hypoglycaemic patients with diabetes, who are prescribed oral hypoglycaemic agents (OHA), experience repeat hypoglycaemic events (RHE) after being treated in the prehospital environment. Methods: A scoping literature review was conducted using an overlapping retrieval strategy that included both published and unpublished literature. Findings: Twenty-three papers and other relevant material were included. Hypoglycaemia related ambulance calls account for 1.3% to 5.2% of ambulance calls internationally. Transportation rates varied between studies (25%-73%). Repeat hypoglycaemic emergencies are experienced by 2-7% of patients within 48 hours. There was insufficient detail to determine any relationship between repeat events and OHA. The low quality of included papers means that the results should be cautiously interpreted. The safety of leaving patients on OHA at home post hypoglycaemic emergency is unknown. Consequently patients taking OHAs who experience a hypoglycaemic emergency should be transported to hospital for observation. There was a lack of knowledge about the Scottish demographics of the patient population. Study two: A retrospective cross-sectional observational study of diabetes related emergency calls. Aims: To investigate i) the patient demographics and characteristics of hypoglycaemia related emergency calls; ii) the incidence of repeat hypoglycaemic events; and iii) the factors associated with emergency calls that result in individuals being left at home. Methods: A retrospective observational cross-sectional study conducted using Medical Priority Dispatch System® call data from West of Scotland Ambulance Control Centre over a 12 month period. Data were extracted on age, gender, dispatch code, time of call, deprivation category, and immediate outcome (home or hospital). Multiple regression analysis was used to determine predictors of remaining at home. Findings: 1319 calls for hypoglycaemia were received. Patient demographics were similar to the scoping review findings. Most patients remained at home (N = 916 vs N = 380; p < .001). RHE’s were experience by 3.1% within 48 hours, and 10.6% within two weeks. The most significant independent predictor for patients remaining at home was a prior call to the ambulance service (OR of 2.4 [95%CI 1.5 to 3.7]). Patients’ reasons for remaining at home and the causes of subsequent severe events are unknown. It is likely that non-clinical factors may explain some of this behaviour. Study 3: Investigating patients’ experiences of prehospital hypoglycaemic care. Aim: To investigate the experiences of patients who are attended by ambulance clinicians for a hypoglycaemic emergency. Methods: In-depth interviews with adults with diabetes who had recently experienced a hypoglycaemic emergency treated by ambulance clinicians. Participants were recruited from Greater Glasgow and Clyde and Lanarkshire Health Board areas. Data were analysed using Framework Analysis. Findings: Twenty six patients were interviewed. Three key themes were developed. Firstly, an explanation for help seeking behaviour; patients’ impaired awareness of hypoglycaemia as well as the inability of friends and relatives to cope can contribute to an ambulance call-out. Secondly, the perceptions of ambulance service care; patients felt the service provided was good; however ambulance clinicians’ advice was inconsistent. Thirdly, the influences on uptake of follow-up care; patient preferences for follow-up care were influenced by previous experiences of home, hospital and primary care. Post-hoc analysis identified three psychological theories that may explain these findings and provide a useful basis for intervention development: Common Sense Model (Leventhal et al, 1998); Health Belief Model (Rosenstock, 1966); Ley’s cognitive hypothesis model of communication (Ley and Llewelyn, 1995; 1981). Conclusion: Most people treated for severe hypoglycaemia by ambulance clinicians remain at home and do not follow-up their care. A few experience repeat hypoglycaemic emergencies. Key causal, but modifiable factors, contributing to this include:- impaired awareness of hypoglycaemia; inconsistent delivery of ambulance clinician referral advice; and patients’ perceptions of the costs and benefits of follow-up care. Ambulance services cannot address all these factors in isolation. The studies in this thesis have generated an evidence base and identified plausible candidate theories. This will support the future development of novel interventions to improve severe hypoglycaemic emergency follow-up.

This study has used a mixed methodology to explore the impact of geographic, temporal and ambulance crew skill factors on ambulance clinicians’ decisions to leave a patient on scene after attending a 999 call. Four phases of work were undertaken using both qualitative and quantitative methods to build an understanding of the complex nature of pre-hospital clinical reasoning. A novel scale, the DMASC survey was developed, which indicated four factors influence decision-making in this context. More experienced staff scored significantly differently to other staff groups on the ‘Experience’ and ‘Patient characteristic’ subscales of the tool. Qualitative work explored these findings in more detail and five inter-related themes were identified, namely, ‘Communication’, ‘The three ‘E’s’, education, experience and exposure’, ‘System influences’, ‘Professionalism’ and ‘Patient characteristics’. The final phase of the study undertook to analyse retrospective call data from one large ambulance service over a one-year period. All of the five predictor variables, rurality, time of day, day of the week, patient condition and crew skill level, influenced the likelihood of conveyance. Of these the level of clinical skill of the first crew at scene was independently significant. The results of this work are discussed in relation to the strategic and operational context of NHS ambulance services. The thesis is structured as a series of papers yet to be submitted for publication. Although this confers a degree of repetition, it provides a logical analysis of the methods used to explore factors that may influence paramedic’s clinical decision making when deciding to leave patients at home following a 999-call attendance.