Clinical Characteristics and Disease Burden of Diabetic Patients Based on Tianjin Regional Database

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

* Primary objectives: describe the proportion of Chinese diabetic/non-diabetic patients with established cardiovascular disease, CKD, or at high cardiovascular risk including hypertension and hyperlipidemia
* Secondary objectives: describe the demographic characteristics of the last visit for all patients, and the demographic characteristics of inpatients over time; investigate the clinical characteristic for all patients


Eligibility Criteria:
Inclusion Criteria:

* Patients in the Tianjin regional database from 01/01/2015 to 31/12/2019
* Group A: patients with diagnosis of diabetes, and with diagnosis of cardiovascular disease, heart failure, chronic kidney disease or at high cardiovascular risk
* Group B: patients with diagnosis of diabetes, but not with diagnosis of cardiovascular disease, heart failure, chronic kidney disease or at high cardiovascular risk
* Group C: patients with diagnosis of cardiovascular disease, heart failure, chronic kidney disease or at high cardiovascular risk, but not with diagnosis of diabetes
* Group D: patients without diagnosis of cardiovascular disease, heart failure, chronic kidney disease or at high cardiovascular risk, and without diagnosis of diabetes. We will randomly select a group of non-diabetic patients without any of the above diseases by matching on age and gender

Definition of diabetes, cardiovascular disease, chronic kidney disease and high cardiovascular risk:

* Diabetes: patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of diabetes (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (International classification of disease (ICD)-10 E10-E14);
* Cardiovascular disease: patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of ischemic heart diseases (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (ICD-10 I20\~I25); or patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of cerebrovascular diseases (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (ICD-10 I60\~I69); or patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of ischemic peripheral artery disease (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (ICD-10 E10.501, E11.603, E14.501, E14.606, E14.503, I73.9, I99.03, I99.04);
* Heart failure: patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of heart failure (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (ICD-10 I50);
* Chronic kidney disease (CKD): inpatients with at least once 1 discharged diagnosis CKD (ICD-10 N18), or inpatients with the last estimated glomerular filtration rate (eGFR, calculated by Chronic Kidney Disease Epidemiology Collaboration (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); or outpatients with at least 2 diagnosis of CKD (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) or with two consecutive eGFR (calculated by CKD-EPI equation) \<60 mL/min/1.73 m2 by 90 days or more;
* High cardiovascular risk: patients with at least 1 discharged diagnosis or 2 outpatient diagnosis of hypertension (the first diagnosis will be the index diagnosis, and the time interval between diagnoses is not restricted) (ICD-10 I10\~I15); or at least 1 discharged diagnosis or 2 outpatient diagnosis of hyperlipidemia (ICD-10 E78.001-E78.003, E78.101, E78.203, E78.301-E78.304, E78.306, E78.401, E78.501, E78.902);

Exclusion Criteria:

* Patients with non-Chinese nationalities
* Duplicated storage (records with same inpatient code)