The heavy disease burden is mainly due to diabetic complications. Diabetes is a major risk factor for cardiovascular disease (CVD) and chronic kidney disease (CKD).China has been the largest absolute disease burden of diabetes in the world recently1. Diabetic patients with established CVD or CKD are bringing growing pressure upon our nation's healthcare expenditure1. However, the characteristic profile of Chinese diabetic patients who has CVD, CKD or at high risk of CVD remains unclear thus is in urgent need for in-depth investigation.In current China, however, the information regarding diabetes or non-diabetes patients who also had other comorbid conditions (e.g. established CV diseases, CKD or at high risk for such problem), is limited; the patient characteristics, treatment patterns and economic burden may not be fully understood.Therefore, based on TianJin regional database, the investigators will describe the demographic, clinical characteristics, treatment, and economic burden of disease of Chinese diabetic/non-diabetic patients with/without established CV disease, CKD, or at high CV risk including hypertension and hyperlipidaemia. And the investigators believe that the resulting findings will inform a comprehensive group of evidence users to achieve better healthcare for diabetes patients with established or at high risk of CVD or CKD.

The study aimed to investigate the clinical characteristics, treatment, and economic burden of disease of Chinese diabetic/non-diabetic patients with/without established cardiovascular disease, chronic kidney disease, or at high cardiovascular risk, including:

1. estimate the proportion of Chinese diabetic/non-diabetic patients with established cardiovascular disease, CKD, or at high cardiovascular risk including hypertension and hyperlipidaemia;
2. describe the demographic and clinical characteristics of Chinese diabetic/non-diabetic patients with/without established cardiovascular disease, CKD, or at high cardiovascular risk;
3. investigate the treatment patterns of Chinese diabetic/non-diabetic patients with/without established cardiovascular disease, CKD, or at high cardiovascular risk;
4. examine economic burden of disease of Chinese diabetic/non-diabetic patients with/without established cardiovascular disease, CKD, or at high cardiovascular risk;
5. explore the trends of clinical characteristics, treatment pattern, economic burden of inpatients over time (2008, 2013, and 2018 separately);

Inclusion Criteria:

• Patients in the TianJin regional database from 2015 to 2018.
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of ischemic heart diseases (ICD-10 I20~I25);
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of cerebrovascular diseases (ICD-10 I60~I69);
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of ischemic peripheral artery disease (ICD-10 E10.501, E11.603, E14.501, E14.606, E14.503, I73.9, I99.03, I99.04);
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of heart failure (ICD-10 I50);
• inpatients with at least once 1 discharged diagnosis CKD (ICD-10 N18), or inpatients with the last estimated glomerular filtration rate (eGFR, calculated by CKD-EPI equation) <60 mL/min/1.73 m2 or prescription of dialysis, but not with the diagnosis of acute kidney injury (ICD-10 N17)
• Outpatients with at least 2 diagnosis of CKD or with two consecutive eGFR(calculated by CKD-EPI equation) <60 mL/min/1.73 m2 by 90 days or more.
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of hypertension (ICD-10 I10~I15);
• at least 1 discharged diagnosis or 2 outpatient diagnosis of hyperlipidaemia (ICD-10 E78.001-E78.003, E78.101, E78.203, E78.301-E78.304, E78.306, E78.401, E78.501, E78.902)
• patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of diabetes (ICD-10 E10-E14)
• In addition, we will randomly select a group of non-diabetic patients without any of the above diseases by matching on age and gender.

Exclusion Criteria:

• Patients with non-Chinese nationalities;
• Patients with abnormal bill (planning to define abnormal bill as the top 1-2.5% of total medical costs in three groups, respectively, but the final standard will be defined based on the real extracted data);
• Duplicated storage (records with same inpatient code).

Diabetic/non-diabetic patients with/without established cardiovascular disease, chronic kidney disease, or at high cardiovascular risk in TianJin regional database