Health literacy of people accessing specialist mental health or substance use disorder treatment services

Background: Multidimensional health literacy refers to the personal knowledge and competencies an individual accumulates, mediated by organisational structures and resource availability, which enable an individual to access, understand, appraise and use health information and services to promote and maintain good health. Research on general populations has found that low health literacy is associated with a range of poorer health outcomes. Minimal research has examined health literacy of people accessing specialist mental health or substance use disorder (SUD) treatment services, despite this population experiencing health inequalities, and requiring good access to healthcare. This thesis comprises four studies which overall aim to explore and understand the multidimensional health literacy levels of people accessing specialist mental health or SUD treatment services. Methods: Study 1 was a systematic review and comprised 14 empirical studies that examined health literacy of people living with mental illness. Study 2 was a cross-sectional study of 325 people accessing specialist mental health services who completed a survey. The multidimensional Health Literacy Questionnaire (HLQ) was used and analysed using latent profile analysis. Health literacy of this sample was also compared to other populations from previously published research. Study 3 was a cross-sectional study of 568 people accessing specialist SUD treatment services. Health literacy and its association with prior healthcare service utilisation was examined using the HLQ and section 11 of the Lifetime Drug Use History Questionnaire. Study 4 examined changes in health literacy and its relationship with post-treatment outcomes for 231 participants exiting specialist SUD treatment services. The HLQ was analysed using latent profile analysis, and a range of treatment outcomes were captured in a survey conducted at first assessment and 6-months post-treatment. Results: Study 1 identified that rates and measures of health literacy varied across studies and highlighted a need for further research within mental health and SUD treatment seeking populations. Study 2 identified three profiles of health literacy amongst people living with serious mental illness: low (n = 67, 20.4%), moderate (n = 201, 61.3%), and high health literacy (n = 60, 18.3%). Health literacy scores varied when compared with a SUD population but were lower on average when compared with the general population. Study 3 identified three profiles of health literacy amongst people accessing specialist SUD treatment services: lowest (n = 86, 15.1%), moderate (n = 338, 59.5%), and highest health literacy (n = 144, 25.4%). Although high rates of primary and acute healthcare service use were identified, there were no significant differences between all health literacy profiles on their access of healthcare services prior to entering specialist SUD treatment. Study 4 identified three health literacy profiles: lowest (n = 52, 22.5%), moderate (n = 111, 48.1%), and highest health literacy (n = 68, 29.4%). Health literacy improved over time for people within the lowest and moderate health literacy profiles. Although, people within the lowest health literacy profile did not reach the same levels as those within the highest health literacy profile and continued to experience poorer treatment outcomes at 6-months post-treatment. Discussion: This thesis demonstrated that there were distinct health literacy profiles in samples accessing specialist mental health and SUD treatment services, and of particular concern were those with lower levels of health literacy. Despite this group improving posttreatment, they still experienced poorer health literacy and treatment outcomes compared with the higher health literacy profile. Findings highlighted the importance of individually assessing health literacy and integrating health literacy tools and interventions at an organisational level, with a focus on people within lowest health literacy profiles. This was the first program of research to explore and examine health literacy within this population. This thesis contributes important insights into the health literacy difficulties experienced by this population, and offers the first platform upon which future research and interventions can be developed