Reliability and Validity of a Manual Dexterity Test to Predict Preclinical Grades

The University of California, San Francisco School of Dentistry wanted to determine if a predental school manual dexterity test predicts: 1) subsequent grades in preclinical restorative courses, and 2) faculty perceptions of satisfactory performance in these skills that would indicate the student is ready to advance to the clinic. The study population was comprised of all 244 applicants admitted to UCSF School of Dentistry's D.D.S. program from Classes of 2000 to 2002 and who matriculated into the program. The manual dexterity test (MDT) consisted of a two-hour block-carving test. Three preclinical faculty, three clinical faculty, and two basic science faculty graded the blocks. Even after instruction and calibration, faculty varied greatly in their grading (intra-rater reliability kappa statistics ranging from 0.34 to 1.00). Two of three preclinical raters gave No Passes for the MDT in 9.8 percent of the incoming, first-year dental students. Of these twenty-three students, only four (17 percent) were in the lower 10 percent of their classes according to their five preclinical restorative laboratory courses after two years, and four (33 percent) were among the twelve students the three preclinical laboratory directors identified as laboratory cautions. The MDT did not significantly (p=0.342) predict students in the bottom 10 percent after five restorative preclinical laboratory courses, above and beyond current admissions criteria. Among current admissions criteria, PAT score was the only item at least moderately correlated with preclinical average percentile class rank (Spearman correlation = 0.34). In conclusion, the MDT did not appear to add information to the current admissions criteria.