Delaney et al (2003) estimated that more than half of all cancer patients should receive radiotherapy at some point during the course of the disease. Actual Radiotherapy Utilisation (RTU) rates are usually lower than the optimal rates.
To calculate the actual RTU rates in NSW & ACT (2004-06) directly from patient treatment records with special emphasis on the effect of geographic variation on RTU.
Radiotherapy treatment data were collected from all 17 radiotherapy departments (RTD) in NSW and ACT for the period January 2004-June 2007. Through Centre for Health Record Linkage the radiotherapy data and Central Cancer Registries (CCR) records in NSW & ACT were linked. GIS software was used to calculate the road distance between patients’ residential address and the closest RTD. Patients were excluded from the study if their nearest RTD was outside NSW or ACT.
The overall raw RTU rate in NSW and ACT (2004-06) was 29%. After data linkage with CCR records, the overall RTU rate was 24% for unique patients diagnosed and treated within the study period. Excluding patients at the borders with other States, the RTU rate was 26%. The RTU rates decreased with increasing distance from patient residence to the nearest radiotherapy facility (p <0.0001). RTU ranged from 27% for those who lived less than 50 km to 19% for those who lived 400+ Km from the nearest RTD.
This is the first study to use data linkage to match radiotherapy treatment data received from all RTD to all CCR records in NSW and ACT. It is also the first study to calculate the road distance between patient residence and the nearest radiotherapy facility. There was a statistically significant difference in radiotherapy access based on road distance.