How reliable is the lacrimal scintigraphy report? An interobserver agreement and reliability study

AIM: To assess the inter-observer agreement and reliability as well as intra-observer repeatability for lacrimal scintigraphy(LS) reports with and without considering the irrigation test results.METHODS: A prospective, observational, cross sectional study. Two masked clinicians(lacrimal surgeon and nuclear medicine specialist) independently reported 100 LS images(50 patients of >6 years of age with unilateral anophthalmic socket) in a university hospital. The lacrimal surgeon performed a diagnostic irrigation test and repeated the report of the same LS images 2 y after the first report(intra-observer agreement). A weighted Kappa analysis was performed to determine inter-observer agreement and reliability as well as intra-observer repeatability for the type(normal, partial and complete obstruction) and location(presac, preduct, and intraduct) of the obstruction. Subgroup analysis was also performed with consideration of irrigation test results. RESULTS: A significantly moderate agreement was found between lacrimal surgeon and nuclear medicine specialist for both the type(Kappa=0.55) and location(Kappa=0.48) of obstruction. Agreement values were higher for the type(Kappa=0.61 vs 0.41) and location(Kappa=0.56 vs 0.31) of obstruction in cases with normal than abnormal irrigation test. Strong and significant intraobserver(lacrimal surgeon) repeatability was found for both the type(Kappa=0.66) and location(Kappa=0.69) of obstruction. LS showed no to slight reliability based on irrigation test.CONCLUSION: A moderate agreement is found between lacrimal surgeon and nuclear medicine specialist regarding the interpretation of LS suggesting the importance ofconsensus groups among nuclear medicine specialists and lacrimal surgeons to create a common language for interpretation of LS. Intra-observer repeatability is strong for the lacrimal surgeon.