Cohort profile: the Liyang cohort study on chronic diseases and risk factors monitoring in China (Liyang Study)

Purpose The Liyang cohort study on chronic diseases and risk factors monitoring in China (Liyang Study) is a prospective population-based study which aims to investigate and identify the determinants of the most prevalent chronic non-communicable diseases (NCDs) and to evaluate the impact of demographic characteristics, lifestyle, dietary habits, cognition, disability and NCDs on the health-related quality of life. Participants Between March 2019 and June 2020, 10 056 individuals aged ≥18 years were administered a baseline survey through a multistage cluster random sampling in Liyang City, southern Jiangsu Province, China. Findings to date The Liyang Study included detailed sociodemographic, anthropometric and health-related behaviour, common NCDs and blood sample information. Moreover, the study gathered a series of data on specific scales including the activities of daily living, instrumental activities of daily living, abbreviated mental test, Food Frequency Questionnaire and EuroQol 5-Dimensions 5-Levels Scale. Of the 10 056 participants, 52.92% (n=5322) were female and 92.26% (n=9278) came from rural areas. The mean age was 49.9±16.2 years. Men were more likely to have a higher level of education, annual income and a paid job than women (p<0.05). The top three overall most prevalent NCDs in the study were hypertension (18.06%, n=1815), digestive diseases (7.88%, n=791), and arthritis or rheumatism (5.28%, n=530). Women had a significantly higher prevalence of diabetes (5.46%, n=290 vs 4.42%, n=209, p=0.016) and arthritis (6.04%, n=321 vs 4.42%, n=209, p<0.001) than men, while the opposite was true for chronic lung diseases such as chronic obstructive pulmonary disease (1.37%, n=65 vs 0.92%, n=49, p=0.032) and chronic hepatic diseases (0.80%, n=38 vs 0.47%, n=25, p=0.035). Future plans The current study will give valuable insights into the association between sociodemographic factors, health-related behaviour, diet, cognition, disability and genetic factors and the most prevalent NCDs among local community residents. Starting from 2022, a follow-up survey will be conducted every 3 years to further explore the causal relationship between the above factors and NCDs.