Forecasting disability-adjusted life years for chronic diseases: reference and alternative scenarios of salt intake for 2017–2040 in Japan

Abstract

Background In Japan, a high-sodium diet is the most important dietary risk factor and is known to cause a range of health problems. This study aimed to forecast Japan’s disability-adjusted life year (DALYs) for chronic diseases that would be associated with high-sodium diet in different future scenarios of salt intake. We modelled DALY forecast and alternative future scenarios of salt intake for cardiovascular diseases (CVDs), chronic kidney diseases (CKDs), and stomach cancer (SC) from 2017 to 2040. Methods We developed a three-component model of disease-specific DALYs: a component on the changes in major behavioural and metabolic risk predictors including salt intake; a component on the income per person, educational attainment, and total fertility rate under 25 years; and an autoregressive integrated moving average model to capture the unexplained component correlated over time. Data on risk predictors were obtained from Japan’s National Health and Nutrition Surveys and from the Global Burden of Disease Study 2017. To generate a reference forecast of disease-specific DALY rates for 2017–2040, we modelled the three diseases using the data for 1990–2016. Additionally, we generated better, moderate, and worse scenarios to evaluate the impact of change in salt intake on the DALY rate for the diseases. Results In our reference forecast, the DALY rates across all ages were predicted to be stable for CVDs, continuously increasing for CKDs, and continuously decreasing for SC. Meanwhile, the age group-specific DALY rates for these three diseases were forecasted to decrease, with some exceptions. Except for the ≥70 age group, there were remarkable differences in DALY rates between scenarios, with the best scenario having the lowest DALY rates in 2040 for SC. This represents a wide scope of future trajectories by 2040 with a potential for tremendous decrease in SC burden. Conclusions The gap between scenarios provides some quantification of the range of policy impacts on future trajectories of salt intake. Even though we do not yet know the policy mix used to achieve these scenarios, the result that there can be differences between scenarios means that policies today can have a significant impact on the future DALYs.

Projections of disability-adjusted life years for major diseases due to a change in vegetable intake in 2017–2040 in Japan

“…We followed the methodological approach of Nomura and Yoneoka et al [ 14 ]. GBD data from 1990 to 2016 were used to predict the future values from 2017 to 2040 for DALYs attributable to three disease groups that have been identified to be associated with low vegetable intake.…”

“…We used consecutive nationwide data from NHNS to characterise sex- and age-specific average daily vegetable intake and prevalence of current smoker, current alcohol drinker, and obesity (defined according to the Japanese definition of a body mass index (BMI) of 25 kg/m 2 or over) following the design of a previous study [ 14 ]. The individual data from NHNS were categorised according to the GBD’s category and combined with DALYs rate by age, sex and survey year.…”

Reduced burden from major diseases due to an increase in vegetable intake in Japan: projections of disability-adjusted life years, 2017-2040

“…Overall forecasting model structure We followed the methodological approach of Nomura and Yoneoka et al (2020) (14). GBD data from 1990 to 2016 were used to predict the future values from 2017 to 2040 for DALYs attributable to three disease groups that have been identified to be associated with low vegetable intake.…”

Umami: An Alternative Japanese Approach to Reducing Sodium While Enhancing Taste Desirability

“…As a result, we found that the percentage of people who meet the dietary goal for seven essential nutrients-designed to reduce the risk of lifestyle-related chronic diseases in Japan's 2015 national nutrient-based dietary guideline-was only 0.3% in 2017 [8]. We have also identified remarkable differences in disease burden between the scenarios, representing a wide scope of future trajectories of food intake with the potential for a tremendous decrease in the burden by 2040 [9] [10]. While it is important to note that foods are more than just a collection of nutrients and that focusing on individual nutrients does not necessarily translate to a healthy diet [11], there is room for Japan to improve its diet to maintain and further develop its population's health.…”