Statistical modelling of geographical trends in the Australian HIV Epidemic

This thesis presents a series of publications analysing geographical trends in Australian HIV incidence, diagnosis and clinical service provision. In Chapter two, estimates of HIV incidence among men who have sex with men are presented using national case reporting surveillance data and a modified statistical back-projection method. It was found that HIV diagnoses in Australia reflected changes in estimated incidence to 2000, and revealed an increase in Queensland in the subsequent ten years. In Chapter three, a study is presented to identify clinical opportunities for targeting HIV testing, by Local Health District of NSW. The Australian HIV database was linked to cancer diagnoses, notifiable condition diagnoses, emergency department presentations and hospital admissions for all HIV diagnoses between 1993 and 2012 in NSW. Date of HIV acquisition was estimated from back-projection models. Sexually transmitted infection diagnoses (particularly gonorrhoea) and some hospital admissions (mental health and non-infective digestive disorder diagnoses) were common among people estimated to be living with undiagnosed HIV. People with these diagnoses could be targeted for increased HIV testing to facilitate earlier and efficient HIV diagnosis. A retrospective analysis of HIV clinical service capacity records in Australia is presented in Chapter four. The number of hospital departments, sexual health services, general practitioners and shared-care services providing expertise in HIV management from 2007 to 2010 was obtained from the Australasian Society for HIV Medicine. There was a decreasing supply of HIV clinical service capacity in Australia despite increasing numbers of people living with HIV (PLHIV). This is extended in Chapter five by elucidating more precisely the number and location of the HIV clinical workforce capacity to enable service planning. A survey of HIV services was conducted and novel geostatistical analysis was used to identify significant regions of clinical service undersupply, relative to the estimated number of PLHIV in 2010 and 2020. In 2010, an estimated 9.7% of all PLHIV resided in regions more than 15 km from a HIV clinical service provider. By 2020, this is estimated to rise to 11.5%. The establishment of new HIV services are most required in the areas of greatest HIV clinical undersupply