Changyu Qu ¹ Juming Liu ^1* Hongjia Liu ² Yongxiang Gong ¹ Meng Guo ³ Yingying Ge ¹ Yuheng Liu ¹ Rui Luo ¹ Meng Yang ¹ Xiuying Li ¹ Yangwenhao Liu ¹ Xiangbin Li ¹ Tiemei He ¹ Xiaodong Liu ¹ Chunrong Huang ¹ Yihua Xu ¹

• ¹ Xiangyang Central Hospital, Xiangyang, China
• ² Hunan University of Technology and Business, Changsha Shi, Hunan Province, China
• ³ Cardiac Rehabilitation Center, Wuhan Asia Heart Hospital, Wuhan, Hubei Province, China

Background: Multimorbidity has become a major public health problem among Chinese middle-aged and elderly adults, and the most costly to the health care system. However, most previous population-based studies of multimorbidity have focused on a limited number of chronic diseases, and diagnosis was based on participants' self-report, which may oversimplify the problem. At the same time, there were few reports on the relationship between multimorbidity patterns and health care costs.This study analysed the multimorbidity patterns and changes among middle-aged and elderly people in China over the past decade, and their association with medical costs, based on representative hospital electronic medical record data.: Two cross-sectional surveys based on representative hospital data were used to obtain adults aged 45 years and older in Xiangyang in 2013(n=20218)and 2023(n =63517). Latent Class Analysis was used to analyze changes in the patterns of multimorbidity,grey correlation analysis and ordered logistics model were used to assess the association of multimorbidity patterns with medical expenses.The diagnosis and classification of chronic diseases were based on the International Classification of Diseases, Tenth Revision codes (ICD-10). Results: The detection rate of chronic disease multimorbidity has increased (70.74% vs 76.63%, P<0.001), and multimorbidity patterns have increased from 6 to 9(2013:Malignant tumors pattern, non-specific multimorbidity pattern, ischemic heart disease+hypertension pattern, cerebral infarction+hypertension pattern, kidney disease+hypertension pattern, lens disease +hypertension pattern;new in 2023: Nutritional metabolism disorders+hypertension pattern , chronic lower respiratory diseases+malignant tumors pattern, gastrointestinal diseases pattern ) in China.The medical cost of all multimorbidity patients have been reduced between 2013 and 2023(RMB:8216.74 vs7247.96,IQR:5802.28-15737 vs 5014.63-15434.06).The top three specific multimorbidity patterns in both surveys were malignancy tumor pattern, ischemic heart disease + hypertension pattern, and cerebral infarction + hypertension pattern.Hypertension and type 2 diabetes are important components of multimorbidity have diversified over the past decade and are associated with rising health care costs in China. Smart, decisive and comprehensive policy and care interventions are needed to effectively manage NCDS and their risk factors and to reduce the economic burden of multimorbidity on patients and the country.