Adding Normal Laboratory Values to Nurse Competence Examinations: Effects on Item Difficulty

Entry-level nurses are expected to know common laboratory values, so they can recognize deviations from normal values. Using an alternate item type, called the exhibit item, test developers can present laboratory values in a more realistic manner, but they have not included normal values in nurse competence examinations. The object of this study was to add normal laboratory values to existing examination items to determine if the calibrated difficulty of the item would be affected. Should item difficulties become significantly easier, the suggestion would be that measurement is related to simple recall rather than an application of knowledge. Should the items become significantly more difficult, the suggestion would be that the measurement construct has shifted from an application of knowledge to higher cognitive levels requiring more complex analysis. Findings of the study indicated slightly more than half of the study items were significantly easier than their source-item counterparts, one-third of the items showed no significant difference in difficulty, and 14 of the study items were significantly more difficult than their source-item counterparts.