Development and validation of an instrument to assess the self- confidence of students enrolled in the advanced pharmacy practice experience

American Journal of Pharmaceutical Education, Spring 2002 by Wongwiwatthananukit, Supakit, Newton, Gail D, Popovich, Nicholas G

When interpreting the rotated three-factor pattern matrix and removing ineffective items from the original 55 items, an item was retained on a given factor if the factor loading was > 0.60 for that factor. Using this criterion, the revised instrument consisted of 34 items. All factor loading values ranged from 0.6003 to 0.9581. Sixteen of these items were found to load onto factor one. This was interpreted as representing the knowledge base and pharmaceutical care subscale. Eleven items loaded onto factor two, which was interpreted as representing the professionalism subscale. Seven items loaded onto factor three. Although the third factor accounted for only 4.9 percent of the total variance, it was relatively well defined, with a clear-cut marker variable that had a factor loading of 0.85. This factor was interpreted as representing the communication skill subscale. Communality values that demonstrated how well items' variance were explained by the three-factor solution ranged from 0.4089 to 0.7686. These values were above 0.30 and indicated that the variance of each item was adequately explained by the three-factor solution(24).

The overall coefficient alpha of the 34-item instrument was 0.9612. Subscale one (16 items), two (11 items), and three (seven items) had coefficient alphas of 0.9570, 0.9234, and 0.9305, respectively. The coefficient alpha did not increase with the deletion of any item for each subscale. All items on the three subscales had the corrected item-subscale correlation coefficients > 0.30. To complete the instrument revision, the 34 items were randomly ordered and formatted again to ensure that there was no anchoring influence by any item order before large scale testing of the instrument.

Step 4: Large Scale Testing of the Instrument

Purpose. To replicate item analysis on the 34-item instrument, to determine the adequacy of fit of the three-subscale structure/model obtained from the pilot test using first-order confirmatory factor analysis, and to perform an analysis of study objective two.

Subjects. Subjects consisted of a sample of 837 fourth professional year PharmD students from 13 schools/colleges of pharmacy (ie., nine public and four private colleges/schools) participating in experiential clerkships during the fall 2000 (ie., October 1 to December 31, 2000). Schools/colleges were recruited to correspond to the national statistics of public to private colleges/schools of pharmacy ratio(18) (ie., 2.3:1.0). Deans and/or experiential program coordinators from 24 colleges/schools of pharmacy (ie., sixteen public and eight private schools/colleges) were randomly selected from the 81 nationwide colleges/schools (i.e., 57 public and 24 private colleges/schools) based on geographic areas (i.e., pacific, mountain, central, eastern). They were then contacted via email and asked to participate in the large scale testing step of this study. Specifically, they were asked if they would be willing to volunteer their enrolled clerkship students to complete the instrument. Thirteen out of the 24 contacted colleges/schools of pharmacy (54 percent) agreed to participate in this study (ie., nine public and four private colleges/schools) yielding a public to private colleges/schools of pharmacy ratio that corresponded to the national statistics(18).

Procedures. A faculty coordinator at each of the 13 colleges/schools of pharmacy received and administered the 34item Clerkship Student Self-Confidence Assessment Instrument and a student demographic form for completion by participating students. Data collected from students were obtained on a cross-sectional basis and would follow the same procedure as the pilot test step.