Shared decision-making (SDM) is a practice in which patients and clinicians work in partnership tochoose treatments, management packages, support packages, or tests based on the patient’sinformed preferences as well as clinical evidence. SDM was a critically important element of the 2016Scottish model of healthcare quality. However, whilst the aim of the Scottish Government was thatSDM should be standard practice in healthcare within Scotland, with decision aids (DAs) used to assistthe SDM process, successful implementation of SDM and DAs is patchy and not currently the normwithin the UK, with no known literature or review for Scotland and its individual health system.Thus, the overall aim of the research reported in this thesis was to identify key factors that will facilitatethe successful implementation of medical SDM in Scotland. Where previous research on SDM hadfocused on healthcare professionals, the thesis made an important contribution to knowledge byfocusing specifically on patients’ attitudes to and engagement with SDM. Conducting this researchwithin Scotland also further contributes original knowledge, where previous research has focused onthe UK as a whole, despite the differences in how health is delivered in its individual nations.A multiphase mixed methods design was employed, consisting of two qualitative studies (studies 1and 4) utilising semi-structured interviews and two quantitative studies (studies 2 and 3) via onlinesurveys. Study 1 investigated the implementation of SDM and DAs in NHS Scotland using thematicanalysis of interviews with members of Scottish NHS boards (n=9), with participants suggesting whileSDM is successfully practiced, barriers such as lack of time, auditing and awareness need to beaddressed, with recommendations provided for both these issues and the effective design andimplementation of DAs. This was followed by two online surveys to identify predictors of bothacceptance of SDM for individuals with chronic pain (study 2; n=195) and engagement with SDM forthe Scottish general population (study 3; n=210). While both studies identified useful predictors toassist in delivering SDM effectively with both populations, it was clear that effective measures of SDMneed to be identified, such as the Theory of Planned Behaviour (TPB) utilised in study 3. Finally,experiences and attitudes towards SDM were investigated through thematic analysis of interviews withboth members of the Scottish general population and individuals with chronic pain (n=24). Despiteoverall positive attitudes towards SDM, participants’ experiences suggest that SDM is inconsistentlyimplemented between healthcare professionals, geographical locations and healthcare departments.Recommendations were provided for training and education for healthcare professionals to achieve awider standard of implementation.The qualitative findings demonstrate despite positive attitudes towards SDM from both healthcareprofessionals and patients, the reports from professionals on successful implementation of SDM didnot align with patient experiences. Recommendations were identified for provider training andeducation on SDM, as well as for the design and implementation of DAs to support SDM. In addition,effective and standardised audits of SDM also need to be implemented in order to adequately assessSDM implementation. The quantitative findings identify factors which were important for individualswith chronic pain to predict their acceptance of SDM, alongside factors which were important formembers of the Scottish general population in predicting their engagement SDM. Importantly,awareness (study 2) and knowledge of SDM (studies 2 and 3) for patients indicates a need for trainingand education in SDM also with patients, not just for healthcare professionals. These studies alsofurther highlighted the need for appropriate academic measures of SDM, such as the TPB.To summarise, both the qualitative and quantitative findings in the thesis highlighted key factors thatwill facilitate the successful implementation of medical SDM in Scotland. Thus, healthcareprofessionals in Scotland, and perhaps even outside Scotland, should aim to implement andincorporate these key factors moving forward to successfully implement medical SDM in Scotland. Thefindings were discussed in relation to the research aims, previous literature, practical implications andideas for future research were also proposed.