How do Japanese rate the severity of different diseases and injuries?—an assessment of disability weights for 231 health states by 37,318 Japanese respondents

Abstract

Background Disability weights (DWs) are weight factors that reflect the severity of health states for estimates of disability-adjusted life years. A new set of global DWs was published for the Global Burden of Diseases and Injuries (GBD) 2013 study, which relied on sampling from various world regions, but included little data for countries in East Asia. This study aimed to measure DWs in Japan using comparable methods, and compare the results with previous estimates from the GBD 2013 DW study. Methods We conducted a web-based survey in 2019 to estimate DWs for 231 health states for the Japanese population. The survey included five new health states but otherwise followed the method of the GBD DW measurement study. The survey consisted of 15 paired comparison (PC) questions and 3 population health equivalence questions (PHE) per respondent. We analyzed PC data using probit regression and rescaled results to DW units between 0 (equivalent to full health) and 1 (equivalent to death). Findings We considered 37,318 nationally representative respondents. The values of the resulting DWs ranged from 0.707 (95% uncertainty interval (UI) 0.527–0.842) for spinal cord injury at neck level (untreated) to 0.004 (UI 0.001–0.009) for mild anemia. High correlation between Japanese DW and GBD 2013 DW was observed, but there was considerable disagreement. Out of 226 comparable health states, 55 (24.3%) showed more than a factor-of-two difference, of which 41 (74.6%) had a higher value in Japanese DW. Many of the health states with higher DW in the Japan study were injuries, including amputation and fracture, and hearing and vision loss, while mental, behavioral, and substance use disorders generally tended to be lower. Conclusions This study has created an empirical basis for assessment of Japanese DWs of health status. The findings from this study based on the Japanese population suggest that there might be contextual differences in rating the severity of health states compared to previous surveys conducted elsewhere.

Eliciting national and subnational sets of disability weights in mainland China: Findings from the Chinese disability weight measurement study

“…The DW values for mild disfigurement is closely to the values in Japan, the DWs of mild and moderate anemia of China and Japan are relatively close, and the values in both countries were higher than those in GBD (appendix p7). 14 The more severe health states of neck pain had much lower Chinese DW values compared to GBD but this was not the case for low back pain. Mild and moderate osteoarthritis of the knee had much higher DWs in China but not the most severe health state.…”

“…The Chinese PHE responses had a more noticeable increasing trend in probabilities with the severity of health states than observed in Japan but less than observed in the GBD 2010 web survey. 3,14…”

“…2,3 Fourth, while the European and Japanese surveys concluded that they could not use the PHE questions because of an inadequate signal among the measurement noise, we found a reasonable differentiation between the 28 PHE questions, though not as much as in the internet survey that was part of the original GBD disability weight surveys. 3,14 Removal of responses that did not meet preset quality criteria may have contributed to better results from the PHE questions, even if that meant dropping as much as 71% of responses. Another factor that may have contributed to better PHE responses is the relatively high level of education that is equivalent to universities and colleges in our study (67% higher education) relative to the Japanese (46%) and European surveys (60%), though not as high as reported for the respondents of the GBD internet survey (93%).…”

“…15,16 In 2019, a national web-based survey conducted in Japan with 37,318 respondents used the methods of the GBD DW measurement study and estimated DWs for 231 health states. 14 Several studies have demonstrated that factors such as nationality, age, sex, disease experience status, income and educational levels 17−21 or profession 22 may have an impact on valuations of health. However, over the past decades, only a European study 17 evaluated the implications of such factors on the valuation of health state severity, and suggested a more systematic approach in future studies, also in non-European countries.…”

Estimating disability-adjusted life years for breast cancer and the impact of screening in female populations in China, 2015–2030: an exploratory prevalence-based analysis applying local weights

“…DALYs have been regarded as a common indicator of burdens of disease in many countries [ 2 ]; DALYs consider both the burden of death (years of life lost [YLLs] due to premature death) and the years lived with disability (YLDs). Population-specific disability weights (DWs) play an important role in the accuracy of YLDs estimations [ 3 , 4 ]. The Global Burden of Disease Study (GBD), an influential global study, evaluated the DALYs associated with more than 300 diseases and injuries.…”