A Review of Utility Measurement Methods Used in Pharmacoeconomic Submissions to HIRA in South Korea: Methodological Consistency and Areas for Improvement

Abstract

Pharmacoeconomic (PE) guidelines, first published in 2006 and later updated in 2011, were developed to guide the preparation and submission of PE data to the Health Insurance Review and Assessment Service (HIRA) for drug reimbursement decision making in South Korea. This study, which was conducted as part of a project for revision of the PE guideline, reviewed utility values used in the PE submissions processed at HIRA during 2014-2018 to identify aspects of the current guidelines that may need to be revisited. A total of 50 PE submissions were processed at HIRA over the 5 years. Of these, 47 submissions that used quality-adjusted life-years as an outcome measure were included in this review. Data were extracted from full copies of the manufacturer's initial submissions and committee documents provided by HIRA. Of the 47 submissions, nearly half (n = 23, 48.9%) used published sources to obtain health state utility values, followed by direct methods using time trade-off (n = 7) or standard gamble (n = 2) and indirect methods with patient-level data using the EQ-5D-3L (n = 4) or the EQ-5D-5L (n = 2). Mapping, using the EQ-5D-3L as a target measure, was also adopted in six submissions, although it was somewhat unfavourably described in the guideline. Notably, 52.2% of the submissions with published sources took utility values from different sources for different health states defined in a single model. In addition, details of utility measurement methods or mapping functions taken from published sources were relatively poorly reported. Moreover, the preferences of the Korean general public, preferred by the guideline, were rarely reflected in the utility values used in submissions relying on published sources (95.7% for foreign values only/mixed) and mapping (66.7%). While most submissions with direct and indirect methods used domestic preference values, the former was occasionally criticised by assessment committees because of health state descriptions. This review highlights a considerable amount of inconsistency in the measurement of utility values used in the PE submissions during 2014-2018, indicating a strong need for methodological standardisation.