This study was done to develop and evaluate a drug dosage calculation training program using cognitive loading theory based on a smartphone application. Calculation ability, dosage calculation related self-efficacy and anxiety were measured.

A nonequivalent control group design was used. Smartphone application and a handout for self-study were developed and administered to the experimental group and only a handout was provided for control group. Intervention period was 4 weeks. Data were analyzed using descriptive analysis, χ²-test, t-test, and ANCOVA with the SPSS 18.0.

The experimental group showed more ‘self-efficacy for drug dosage calculation’ than the control group (t= 3.82, p< .001). Experimental group students had higher ability to perform drug dosage calculations than control group students (t= 3.98, p< .001), with regard to ‘metric conversion’ (t= 2.25, p = .027), ‘table dosage calculation’ (t= 2.20, p = .031) and ‘drop rate calculation’ (t= 4.60, p< .001). There was no difference in improvement in ‘anxiety for drug dosage calculation’. Mean satisfaction score for the program was 86.1.

These results indicate that this drug dosage calculation training program using smart-phone application is effective in improving dosage calculation related self-efficacy and calculation ability. Further study should be done to develop additional interventions for reducing anxiety.