The impacts of withdrawal and replacement of general practitioner services on aeromedical service trends: A 13-year interrupted time-series study in Tennant Creek, Northern Territory

Background: The Royal Flying Doctor Service (RFDS) provides aeromedical care to patients during fixed-win transport over vast distances to healthcare unavailable in rural or remote communities. This study examined th relationship between changes in local accessibility to primary healthcare services and rates of aeromedical servic use over time Methods: This was a 13-year interrupted time-series study (1999-2012) in Tennant Creek, Northern Territory Quarterly aeromedical service use for primary care sensitive conditions were calculated and exposure to genera practice (GP) services was characterised over time with events modelled as intervention variables: (a) GP servic withdrawal (Nov-2004); and (b) GP service replacement (Dec-2006). Intervention effects were estimated usin PROC ARIMA in SAS after examination of the time-series structure Results: GP withdrawal resulted in an immediate and sustained doubling in quarterly aeromedical service us (+11.8 services per quarter) and GP service replacement had no significant effect Discussion: Large and immediate increases in aeromedical service use result from the loss of local GPservice yet, in this case, replacement with a new GP service, 2-years hence, did not ameliorate that effect after six years Conclusions: These findings demonstrate the immediate impact of GP-service loss on the rates ofaeromedica transfer of patients from this remote community and lend caution to expectations about thetimeline over whic newly implemented primary health care services in such contexts can mitigate the impact of such a loss.