TY - JOUR
T1 - Temporal stability of objective structured clinical exams
T2 - A longitudinal study employing item response theory
AU - Baig, Lubna A.
AU - Violato, Claudio
PY - 2012
Y1 - 2012
N2 - Background: The objective structure clinical examination (OSCE) has been used since the early 1970s for assessing clinical competence. There are very few studies that have examined the psychometric stability of the stations that are used repeatedly with different samples. The purpose of the present study was to assess the stability of objective structured clinical exams (OSCEs) employing the same stations used over time but with a different sample of candidates, SPs, and examiners. Methods. At Time 1, 191 candidates and at Time 2 (one year apart), 236 candidates participated in a 10-station OSCE; 6 of the same stations were used in both years. Generalizability analyses (Ep2) were conducted. Employing item response analyses, test characteristic curves (TCC) were derived for each of the 6 stations for a 2-parameter model. The TCCs were compared across the two years, Time 1 and 2. Results: The Ep2 of the OSCEs exceeded.70. Standardized thetas (θ) and discriminations were equivalent for the same station across the two year period indicating equivalent TCCs for a 2-parameter model. Conclusion: The 6 OSCE stations used by the AIMG program over two years have adequate internal consistency reliability, stable generalizability (Ep2) and equivalent test characteristics. The process of assessment employed for IMG's are stable OSCE stations that may be used several times over without compromising psychometric properties. With careful security, high-stakes OSCEs may use the same stations that have high internal consistency and generalizability repeatedly as the psychometric properties are stable over several years with different samples of candidates.
AB - Background: The objective structure clinical examination (OSCE) has been used since the early 1970s for assessing clinical competence. There are very few studies that have examined the psychometric stability of the stations that are used repeatedly with different samples. The purpose of the present study was to assess the stability of objective structured clinical exams (OSCEs) employing the same stations used over time but with a different sample of candidates, SPs, and examiners. Methods. At Time 1, 191 candidates and at Time 2 (one year apart), 236 candidates participated in a 10-station OSCE; 6 of the same stations were used in both years. Generalizability analyses (Ep2) were conducted. Employing item response analyses, test characteristic curves (TCC) were derived for each of the 6 stations for a 2-parameter model. The TCCs were compared across the two years, Time 1 and 2. Results: The Ep2 of the OSCEs exceeded.70. Standardized thetas (θ) and discriminations were equivalent for the same station across the two year period indicating equivalent TCCs for a 2-parameter model. Conclusion: The 6 OSCE stations used by the AIMG program over two years have adequate internal consistency reliability, stable generalizability (Ep2) and equivalent test characteristics. The process of assessment employed for IMG's are stable OSCE stations that may be used several times over without compromising psychometric properties. With careful security, high-stakes OSCEs may use the same stations that have high internal consistency and generalizability repeatedly as the psychometric properties are stable over several years with different samples of candidates.
KW - Ep
KW - Internal consistency
KW - Latent trait analyses
KW - Stability of OSCEs
UR - http://www.scopus.com/inward/record.url?scp=84870512759&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84870512759&partnerID=8YFLogxK
U2 - 10.1186/1472-6920-12-121
DO - 10.1186/1472-6920-12-121
M3 - Article
C2 - 23216816
AN - SCOPUS:84870512759
SN - 1472-6920
VL - 12
JO - BMC medical education
JF - BMC medical education
IS - 1
M1 - 121
ER -