Evidence-Based Cutoff Threshold Values from Receiver Operating Characteristic Curve Analysis for Knee Osteoarthritis in the 50-Year-Old Korean Population: Analysis of Big Data from the National Health Insurance Sharing Service

Figure 2

Pathogenesis of OA in each age group. Carefully extracted patients with OA who had only one hospital visit and OA prescription record in the NHISS from 2002 to 2013 were categorized into four age groups with increments of 10 years (40–49, 50–59, 60–69, and 70–79 years). Each angle from the linear functional graph in each age group was calculated to determine the increase or decrease of OA pathogenesis in patients. From this figure, the 50-year age group was selected and further investigated because the maximum OA occurrence was observed in this age group (An, 8.9). Compared with the 40- and 50-year age groups, the number of patients older than 60 years with OA pathogenesis unexpectedly decreased. OA, osteoarthritis; An, angle.