Determining defensible cut-off scores for dental courses

Many countries and institutions have a fixed passing score of 60%. For example, this is a national policy in all Saudi universities where students at all levels must score 60% or higher to pass courses. The purpose of this study is to broaden the scope of standard-setting applications, using data from five major dental courses (Endodontics, Operative, Removable and Fixed Prosthodontics, and Pedodontics) in the 5th dental academic year for two consecutive years to determine the cut-off scores.

Four expert raters conducted Angoff's method on final examinations of five dental courses to determine the cut-off scores for the two academic years (2015, and 2016). Cohort size of 2015 was 120 students, whilst that of 2016 was 142 students. The study was conducted at the faculty of Dentistry, at King Abdulaziz University (KAU) from December 2017 to June 2018.

All five dental courses yielded different cut-off scores than the fixed 60%. The cut-off scores for 2015 and 2016 examinations were 59.15%, 63.75% for Removable Prosthodontics, 51.86%, 53.75% for Fixed Prosthodontics, 47.42%, 50.5% for Pedodontics, 74.22%, 74.31% for Endodontics and 58%, 55.55% for Operative Dentistry.

Angoff method yielded different cut-off scores than the fixed 60% passing score currently used by the dental school, yielding a difference in pass-fail rates by as much as a staggering 41%. This finding provides support to use evidence-based standard-setting methods to determine the cut-off score for the courses in Dentistry programme.