Abstract
Inflammatory Bowel Disease (IBD) is a chronic disease consisting of Crohn’s Disease (CD), Ulcerative Colitis (UC) and IBD-unclassified (IBD-U). IBD management entails long-term medicines therapy with patients needing to follow prescribed regimens (practice medication adherence (MA)). Poor MA is linked with increased disability, morbidity, mortality and health costs, besides reduced quality of life and worse disease outcomes. Research on MA in Aotearoa New Zealand (NZ) patients with IBD is very limited, with only one regional study published which indicated that a third of patients in southern NZ have poor MA. Therefore, this thesis aimed to holistically investigate the MA - experiences, both national and regional levels, and the relation with disease outcomes – of NZ patients with IBD, alongside data availability for MA assessment and policies on MA promotion.
The first study explored Otago, NZ IBD patients’ experiences with MA via focus group discussions. The data were analysed using reflexive thematic analysis from a ‘direct realist’ viewpoint. Participants perceived MA as a “duty” that was very important to their wellbeing and their MA was centred around a routine requiring proactivity to maintain. Side effects and regimen factors such as a high number of pills and frequency of dosage negatively affected MA. Additionally, obtaining refills was described as a difficult task. Conversely, healthcare professionals played a significant role in supporting and facilitating MA. The support structures identified included family, friends and colleagues as well as targeted health system factors e.g. medication subsidies.
The second study used national dispensing claims and hospitalisation data (Pharmaceutical Collection and National Minimum Dataset) in investigating nationwide MA levels of NZ IBD patients, over three and five years, using daily polypharmacy possession ratio (DPPR). The relationship between MA and the numbers of hospitalisations, and corticosteroid dispensings was also investigated. The three- and five- year cohorts had 4654 and 3148 patients, respectively. Average MA estimates were moderately high at 77.4% and 74.9% over three and five years, while 54% and 51% of patients, respectively, had good adherence (MA≥80%). There was no correlation between MA and the numbers of hospitalisations, and corticosteroid dispensings for both the three- and five- year cohorts.
The third study explored the availability of electronic health records in southern NZ for estimating IBD patient’s MA, and its relationship with corticosteroid dispensings. Medication dispensing data of IBD patients of the former Southern District Health Board (DHB) were curated, from a patient management database, to estimate MA (DPPR) over three years for 108 patients. The mean MA was high at 83.2%, and 69% of patients had MA≥80% (good adherence). Median MA was significantly higher for males versus females (96% vs 83%). There was no correlation between DPPR and the number of corticosteroid dispensings. These findings should be considered with caution due to the uncertain amount and type of missing data in the database. This is because the data were not obtained from all prescribers or pharmacies.
The fourth study collated MA promotion strategies recommended in eight national NZ health/medicines policies, using documentation analysis, to outline the MA policy landscape for the first time. Interventions targeted health system, socioeconomic, disease, therapy and patient-specific factors. Incorporating MA promotion across the health system (in IT platforms, MA services and others) with the collaboration of all healthcare professionals, pharmacists especially, was central to the interventions as was including patients in medicines therapy decisions via robust communication. The interventions aligned with the MA needs of NZ chronic disease (e.g. IBD) patients, indicating that implementing them could improve patients’ MA. The lack of a national MA policy or responsible entity and other policy gaps were spotlighted for resolution. Implementing the interventions would require multipronged efforts of stakeholders across government, the pharmacy/medicine sectors, academia and more.
NZ patients with IBD are motivated to practice good MA but face challenges which need to be addressed from the patient to the health system levels. Long-term MA for IBD patients, both nationwide and within the regions of the former Southern DHB, appears high on average. Just over half and two thirds of patients nationwide and regionally, respectively, meet the good MA threshold. There was no correlation between nationwide or Southern DHB MA (DPPR) and the number of concurrent hospitalisations or corticosteroid dispensings. This may have been impacted by the lack of a lag period before counting hospitalisation/steroid dispensing numbers due to data maximisation realities, and heterogeneities in the study populations (including patients of all ages, disease types/severities etc.) and medications (DPPR assesses MA to polypharmacy, but each medicine might impact disease outcomes differently). Further research should consider these and other factors. High quality health and medicines datasets, including prescription and dispensing data, are available in NZ but require optimisation for use in calculating MA. Health and medicines policies have also proposed interventions for promoting MA and these align with the MA needs of patients with chronic diseases e.g. IBD. However, further research and efforts in policy implementation are needed to translate the recommendations to practice.