Accrual to Trans-Tasman Radiation Oncology Group-sponsored trials 2010-2012

Few trials groups report analyses of accrual. Although Trans-Tasman Radiation Oncology Group (TROG) has reported accrual within individual trials, no analysis has ever been reported. Type A trials are those trials for which TROG is the principal sponsor and are dependent on accrual from TROG centres. The aim of this study was to review accrual rates to type A trials over the last 3 years.

All type A trials that had presented accrual data during the TROG annual scientific meetings and the trials review meetings between April 2010 and April 2012 were reviewed. Expected accrual rate (EAR) and actual accrual rate (AAR) were estimated from accrual curves as well as initial delays in accrual. Ratios of AAR to EAR (RAEAR) were calculated.

There were 16 type A trials from which estimates could be made. The median EAR was 40 patients per year and the median AAR was 20 patients per year. Wide variations in each were noted and the median RAEAR was 0.67. The median initial delay was 7.5 months.

Although TROG is a highly successful trials organisation, the median AAR is only half of the median EAR and in only three trials (19%) was the AAR the same or more than the EAR. Future reports could address potential factors affecting the AAR but would require prospective data collection. The RAEAR is one of many factors that can be used to help determine which trials should continue. Overall rates of accrual can be used as a record of TROG's productivity.