L Prieto1, J A Sacristán, J C Gómez. 1. Health Outcomes Research Unit, Eli Lilly & Co., Alcobendas (Madrid), Spain. prieto_luis@lilly.com
Abstract
OBJECTIVE: The global index of safety (GIS) is an adverse event (AE) based instrument designed to evaluate the safety profile of drugs. This paper presents the evaluation of the inter-rater reliability and validity of a 94-item GIS for antipsychotics through Rasch analysis. RESEARCH DESIGN AND METHODS: A total of 194 psychiatrists participating in an outpatient pharmacoepidemiologic study of olanzapine in schizophrenia rated the severity that each AE would have on a 5-point scale. Reliability was determined through a paired comparison design involving the new independent ratings of 101 different psychiatrists participating in another study of olanzapine in acute inpatient units. Spearman's, Pearson's and Intra-class correlation (ICC) coefficients were used to estimate the inter-rater reliability of the AE weights. Validity was analyzed through the Rasch rating scale model. RESULTS: Reliability coefficient estimates were excellent (Spearman = 0.99, Pearson = 0.99, ICC = 0.98), supporting the inter-rater reliability of the item weights. Through goodness-of-fit statistics and the investigation of the hierarchy of item calibrations, Rasch analysis confirmed the validity of the instrument. CONCLUSION: The data presented here on inter-rater reliability estimates of adverse events related to antipsychotic drugs indicate that GIS is a promising alternative for the evaluation of the safety profile of drugs.
OBJECTIVE: The global index of safety (GIS) is an adverse event (AE) based instrument designed to evaluate the safety profile of drugs. This paper presents the evaluation of the inter-rater reliability and validity of a 94-item GIS for antipsychotics through Rasch analysis. RESEARCH DESIGN AND METHODS: A total of 194 psychiatrists participating in an outpatient pharmacoepidemiologic study of olanzapine in schizophrenia rated the severity that each AE would have on a 5-point scale. Reliability was determined through a paired comparison design involving the new independent ratings of 101 different psychiatrists participating in another study of olanzapine in acute inpatient units. Spearman's, Pearson's and Intra-class correlation (ICC) coefficients were used to estimate the inter-rater reliability of the AE weights. Validity was analyzed through the Rasch rating scale model. RESULTS: Reliability coefficient estimates were excellent (Spearman = 0.99, Pearson = 0.99, ICC = 0.98), supporting the inter-rater reliability of the item weights. Through goodness-of-fit statistics and the investigation of the hierarchy of item calibrations, Rasch analysis confirmed the validity of the instrument. CONCLUSION: The data presented here on inter-rater reliability estimates of adverse events related to antipsychotic drugs indicate that GIS is a promising alternative for the evaluation of the safety profile of drugs.
Authors: Sanne Koops; Edwin van Dellen; Maya J L Schutte; Wendy Nieuwdorp; Sebastiaan F W Neggers; Iris E C Sommer Journal: Schizophr Bull Date: 2015-07-28 Impact factor: 9.306