Uneven access to primary care can widen health inequities and shift demand towards emergency medical services, particularly outside office hours and in rural areas. Quantifying these patterns can support equity-focused planning in family medicine. The study setting includes dispersed rural communities and a culturally and linguistically diverse population.To assess whether family medicine service availability is associated with ambulance service utilisation across administrative areas, focusing on out-of-hours demand and urban-rural differences, and to identify areas with persistently high out-of-hours demand.This study uses linked routinely collected administrative data in an area-by-year framework over 13 years. Ambulance dispatch records (place of request and timestamp) are linked to health insurance indicators at area level, including total resident population, insured and uninsured counts, contracted family medicine practice points, and contextual vulnerability indicators (disability and social care-related counts, such as sickness disability pension, institutionalised persons and placement centres). Outcomes are annual ambulance request rates per 1,000 residents and out-of-hours request rates. Primary care capacity is measured as contracted family medicine practice points per 10,000 residents. Temporal trends and area-level differences are examined, and count regression models with population offsets adjust for vulnerability indicators, the proportion uninsured, and urban-rural classification.Administrative indicators confirm feasibility for rate estimation and show a decline in contracted family medicine practice points over time. Area-level utilisation metrics are derived from ambulance dispatch data and combined with administrative indicators. The analysis quantifies geographic and temporal variation in ambulance demand and estimates adjusted associations between primary care capacity and overall and out-of-hours ambulance utilisation.Linked administrative data can help distinguish structural access gaps from expected demand, and out-of-hours utilisation may act as a marker of unmet access to timely primary care.This approach can identify inequities in access to primary care and prioritise areas for targeted workforce planning and access interventions in underserved communities.