Background
The Australian government sponsored trials aimed at addressing problems in after hours primary medical care service use in five different parts of the country with different after hours care problems. The study's objective was to determine in four of the five trials where telephone triage was the sole innovation, if there was a reduction in emergency GP after hours service utilization (GP first call-out) as measured in Medicare Benefits Schedule claim data. Monthly MBS claim data in both the pre-trial and trial periods was monitored over a 3-year period in each trial area as well as in a national sample outside the trial areas (National comparator). Poisson regression analysis was used in analysis.

Results
There was significant reduction in first call out MBS claims in three of the four study areas where stand-alone call centre services existed. These were the Statewide Call Centre in both its Metropolitan and Non-metropolitan areas in which it operated - Relative Risk (RR) = 0.87 (95% Confidence interval: 0.86 - 0.88) and 0.60 (95% CI: 0.54 - 0.68) respectively. There was also a reduction in the Regional Call Centre in the non-Metropolitan area in which it operated (RR = 0.46 (95% CI: 0.35 - 0.61) though a small increase in its Metropolitan area (RR = 1.11 (95% CI: 1.06 - 1.17). For the two telephone triage services embedded in existing organisations, there was also a significant reduction for the Deputising Service - RR = 0.62 (95% CI: 0.61 - 0.64) but no change in the Local Triage centre area.

Conclusion
The four telephone triage services were associated with reduced GP MBS claims for first callout after hours care in most study areas. It is possible that other factors could be responsible for some of this reduction, for example, MBS submitted claims for after hours GP services being reclassified from 'after hours' to 'in hours'. The goals of stand-alone call centres which are aimed principally at meeting population needs rather than managing demand may be being met only in part.