To investigate the chronological patterns of diseases in Northern Gyeonggi-do province, South Korea, and compare these with national data.

A National Health Insurance cohort based on the National Health Information Database (NHID Cohort 2002–2013) was used to perform a retrospective, population-based study (46,605,433 of the target population, of which 1,025,340 were randomly sampled) to identify disease patterns from 2002 to 2013. Common diseases including malaria, cancer (uterine cervix, urinary bladder, colon), diabetes mellitus, psychiatric disorders, hypertension, intracranial hemorrhage, bronchitis/bronchiolitis, peptic ulcer, and end stage renal disease were evaluated.

Uterine cervix cancer, urinary bladder cancer and colon cancer had the greatest rate of increase in Northern Gyeonggi-do province compared with the rest of the country, but by 2013 the incidence of these cancers had dropped dramatically. Acute myocardial infarction and end stage renal disease also increased over the study period. Psychiatric disorders, diabetes mellitus, hypertension and peptic ulcers showed a gradual increase over time. No obvious differences were found for intracranial hemorrhage or bronchitis/bronchiolitis between the Northern Gyeonggi-do province and the remaining South Korean provinces. Malaria showed a unique time trend, only observed in the Northern Gyeonggi province, peaking in 2004, 2007 and 2009 to 2010.

This study showed that the Northern Gyeonggi-do province population had a different disease profile over time, compared with collated data for the remaining provinces in South Korea. “Big data” studies using the National Health Insurance cohort database can provide insight into the healthcare environment for healthcare providers, stakeholders and policymakers.