Improving serum calcium test ordering according to a decision algorithm

Aim To detect differences in the pattern of serum calcium tests ordering before and after the implementation of a decision algorithm. Methods We studied patients admitted to an internal medicine ward of a university hospital on April 2013 and April 2016. Patients were classified as critical or non-critical on the day when each test was performed. Adequacy of ordering was defined according to adherence to a decision algorithm implemented in 2014. Results Total and ionised calcium tests per patient-day of hospitalisation significantly decreased after the algorithm implementation; and duplication of tests (total and ionised calcium measured in the same blood sample) was reduced by 49%. Overall adequacy of ionised calcium determinations increased by 23% (P=0.0001) due to the increase in the adequacy of ionised calcium ordering in non-critical conditions. Conclusions A decision algorithm can be a useful educational tool to improve adequacy of the process of ordering serum calcium tests.