Prevalence and Overlap of Cardiovascular, Kidney, and Metabolic Diseases in Korea: A Population-based Study

Inclusion criteria

• For an eligible participant, all inclusion criteria must be answered "yes".

Primary Analysis:

• Enrolled in the Korean National Health Insurance Service (NHIS) with valid insurance eligibility during the assessment year.
• Adults aged 19 years or older at the index date (January 1 of each assessment year, annually from 2013 to 2023).

Secondary Analysis (Subgroup Cohorts):

• Enrolled in the Korean National Health Insurance Service (NHIS) with valid insurance eligibility during the cohort entry year.
• Adults aged 19 years or older at the cohort entry date (i.e., the index date defined per the relevant subgroup cohort in) (per the SAP).
• Meets the operational definition of the index disease or state for one of the four pre-specified subgroup cohorts (MASLD, HF, CKM stage, or High obesity) (per the SAP).

Exclusion criteria

• For an eligible participant, all exclusion criteria must be answered "no".

Primary Analysis:

• Individuals with missing age or sex information in the NHIS database.
• Individuals with less than 1 year of continuous enrollment prior to the index date (to ensure adequate lookback period for disease identification).

Secondary Analysis (Subgroup Cohorts)

• Individuals with missing age or sex information in the NHIS database.
• Individuals with less than 1 year of continuous NHIS enrollment prior to the cohort entry date (to ensure adequate washout for incident-case ascertainment).
• Individuals with prior record of respective disease within the 1-year lookback window