Background: Multiple mini-interviews (MMIs) are a valuable tool in medical school selection due to their broad acceptance and promising psychometric properties. With respect to the high expenses associated with this procedure, the discussion about its feasibility should be extended to cost-effectiveness issues.
Methods: Following a pilot test of MMIs for medical school admission at Hamburg University in 2009 (HAM-Int), we took several actions to improve reliability and to reduce costs of the subsequent procedure in 2010. For both years, we assessed overall and inter-rater reliabilities based on multilevel analyses. Moreover, we provide a detailed specification of costs, as well as an extrapolation of the interrelation of costs, reliability, and the setup of the procedure.
Results: The overall reliability of the initial 2009 HAM-Int procedure with twelve stations and an average of 2.33 raters per station was ICC=0.75. Following the improvement actions, in 2010 the ICC remained stable at 0.76, despite the reduction of the process to nine stations and 2.17 raters per station. Moreover, costs were cut down from $915 to $495 per candidate. With the 2010 modalities, we could have reached an ICC of 0.80 with 16 single rater stations ($570 per candidate).
Conclusions: With respect to reliability and cost-efficiency, it is generally worthwhile to invest in scoring, rater training and scenario development. Moreover, it is more beneficial to increase the number of stations instead of raters within stations. However, if we want to achieve more than 80 % reliability, a minor improvement is paid with skyrocketing costs.