Psychosocial Issues and Adherence Rates of Private and Public Patients with Diabetic Macular Edema Undergoing Intravitreal Injection Treatment

Submission note: Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy to the Department of Clinical Vision Sciences, School of Allied Health, College of Science, Health and Engineering, La Trobe University, Victoria, Australia.

Thesis with publications.

The public version of this thesis does not contain all material submitted for examination.

Diabetic macular edema (DME) is caused by leakage of fluid from damaged blood vessels. Vascular endothelial growth factor (VEGF) is elevated in eyes with DME and results in vascular leakage. DME is currently treated with intravitreal anti-VEGF injections. This commonly performed procedure involves multiple injections every four to eight weeks until the fluid is resolved. However, clinic visits could be continued indefinitely to maintain vision, imposing a high burden on patients (e.g. time off work, assistance from family members or carers, financial costs, negative emotional reactions and treatment-related side effects). Extensive research is required to highlight these largely unexplored psychosocial issues on DME patients undertaking this treatment regime. Two studies were conducted. The principal aims of Study 1 was to explore the experiences and perceptions of patients diagnosed with DME undergoing repeat intravitreal injection treatment and to compare whether there were differences in the experiences and perceptions of these patients depending upon whether treatment was performed in a private ophthalmic clinic or public hospital outpatient ophthalmic clinic. The aims of Study 2 was to identify clinical adherence and nonadherence rates of private and public patients with DME undergoing intravitreal injection treatment and identify contributing factors that are associated with adherence and non-adherence. In Study 1, purposive sampling was utilised to recruit DME patients from one private and one public eye clinic. A mixed-methods study was conducted and in total, 28 DME participants (14 public and 14 private patients) completed two questionnaires – Satisfaction with Information about Medicine Scale (SIMS) and Beliefs about Medicines Questionnaire-Specific (BMQ-Specific) – and underwent semi-structured in-depth interviews. An interview guide was used to direct the conversation with participants. The SIMS results identified a non-significant trend that suggested that levels of treatment information satisfaction were slightly higher in private compared to public DME patients (equals 0.602). The BMQ-Specific also revealed a non-significant trend that private patients had slightly stronger beliefs regarding the necessity of xvi intravitreal injection treatment in comparison to public patients (equals 0.158). The BMQ-Specific’s concerns subscale scores also suggested a non-significant trend that public patients were slightly more concerned about intravitreal injection treatment (equals 0.701). Utilising the scores of the BMQ-Specific private and public DME patients were categorised into the Necessity Concerns Framework. Most DME patients considered intravitreal treatment a high necessity however, public and private patients differed in their perceived concerns regarding intravitreal injection treatment. The findings from the semi-structured in-depth interview identified that most patients developed a good understanding of the treatment’s purpose and more private patients were aware of the possibility of undergoing treatment indefinitely. The public patients displayed limited knowledge of the potential side effects, but both groups revealed a high level of trust in their ophthalmologist and confidence in the treatment recommended. Both private and public patients expressed numerous negative initial reactions to the requirement of eye injection treatment, but the majority reported high satisfaction with the results of the treatment. In Study 2, a retrospective chart review of medical records was conducted to assess and compare the adherence rates of DME patients receiving intravitreal treatment at the Royal Victorian Eye and Ear Hospital’s (RVEEH’s) Avastin injection clinic (public) and retinal clinics at the Cheltenham Eye Centre (CEC; private), from 1 January 2014 to 31 December 2014. Telephone interviews with open-ended questions were then conducted to explore factors that contributed to adherence and non-adherence to appointments. Clinical adherence rates of patients with DME undergoing intravitreal injection treatment were higher at the private ophthalmology clinic (85 percent) in comparison to the public hospital outpatient ophthalmic clinic (77 percent). Factors such as driving, family, recreation and vision maintenance were cited by both private and public patients as reasons for adhering to appointments. Fear of blindness, the desire to maintain independence and the prospect of improving vision were commonly mentioned reasons for adherence by the public patients, whereas private patients referred to fear of vision impairment or loss as their major incentive. The public patients made numerous references to the fear of an injection in the eye and cited travel and transportation difficulties as reasons for non-adherence, whereas the private patients cited treatment cost factors, administrative error and illness. The current study identified differences and similarities in the experiences, perceptions, QoL impact and reasons for adherence and non-adherence in private and public DME patients undergoing intravitreal injection treatment. The results of Study 1 have provided a significant contribution to our understanding of the functional status, treatment impact, treatment-related anxiety, importance of undergoing treatment, patient treatment preferences and patients’ satisfaction with information received in private and public DME patients. These findings will serve to improve the effectiveness of treatment and the well-being of patients with DME. As understanding the reasons for non-adherence is crucial for the improvement of patient adherence to intravitreal injection treatment, study 2 has also determined adherence rates and identified reasons why patients with DME do not adhere to appointments to receive treatment. The determination of non-adherence rates and reasons for non-adherence is crucial for health care professionals to identify patients who are at an increased risk of treatment non-adherence.