Applied Primary Health Care Epidemiology in Tasmania

Abstract

This thesis comprises four major projects completed for the Master of Philosophy in Applied Epidemiology (MAE). All four of the projects are in primary health care epidemiology in Tasmania and comply with the key requirements of the MAE program, which are to: 1) analyse a dataset, 2) perform an epidemiological study, 3) investigate an urgent public health problem, 4) evaluate a surveillance system. In the first chapter, I present the findings of a data analysis of all ambulance dispatches in Tasmania from 2009 to 2015. In this analysis I assessed the completeness of the dataset and analysed the temporal, demographic, clinical and spatial characteristics of ambulance dispatches in the study period. The completeness of the data was very high. The key finding was that there was a statistically significant increase in the age-standardised annual incidence rate of ambulance dispatches over the study period. Adults over 85 years had the highest rate of ambulance dispatches, 17-fold higher than the youngest age group of five to 14 years. There were also variations in the time of day, day of the week, month of the year, dispatch categories, paramedic diagnosis, transfer information and geospatial characteristics of the ambulance dispatches. The second chapter is an epidemiological study that I performed to investigate the relationship between fine particulate matter generated by landscape fires and emergency ambulance dispatches in Tasmania using a case crossover design. We investigated the exposure to fine particulate matter at lag times of 1-48 hours prior to the event and the 24-hour average for the 24 hours prior to the event and 24-48 hours prior to the event. The main finding was that increased fine particulate matter was positively associated with the emergency ambulance dispatch categories of stroke, breathing problems and diabetic problems and the final paramedic assessment of asthma at different lag times. The third chapter is a report of a public health investigation into an outbreak of gastroenteritis that occurred following a Mother's Day High Tea in Tasmania in 2016. I used a retrospective cohort design to investigate the outbreak in association with environmental and laboratory investigations. The findings of the investigations supported the initial hypothesis that undercooked chicken wontons were the most likely cause of the outbreak but that cross-contamination of another food source could not be ruled out. In the fourth chapter I present the findings of my evaluation of the Tasmanian real-time prescription monitoring system (RTPMS), which is used to monitor controlled drug dispensing events in Tasmania. Tasmania is currently the only state in Australia to have a RTPMS. I performed a mixed methods evaluation using the United States Centre for Disease Control and Prevention Framework for Evaluating Surveillance Systems. Participation rates for use of the system were moderate among pharmacists and low among General Practitioners. Key informants and health practitioners that I interviewed reported that they found the system simple and easy to use and valued the contributions of the staff that operate the system. There were limited data available to assess the surveillance system attributes, such as sensitivity and positive predictive value, and no evidence to determine if its overall aim - to reduce opioid-related harms in Tasmania - had been achieved. In the evaluation I make a number of recommendations to improve participation rates and address the gaps in data collection, collation, analysis and dissemination.