Considering its distribution and prior publication [27 (link)], duration of diabetes was considered in 5-year strata, allocating the participants into three groups: < 5 years, 5–9 years, and ≥ 10 years from the time of diagnosis. The survey sampling methods of the KNHANES (multistate, stratified, and clustered sampling) were considered in all statistical analyses. In the multivariable logistic regression models, odds ratios (OR) and 95% confidence intervals (CI) were calculated for the association between the duration of illness and the prevalence of hyperglycemia, hypertension, and dyslipidemia. Potential confounding factors and effect modification were considered and examined through literature review [7 (link)8 (link)9 (link)10 (link)11 (link)28 (link)29 (link)] and descriptive statistical analysis approaches. Using SAS PROC SURVEYREG (version 9.4, SAS Institute Inc., Cary, NC, USA), multivariable generalized linear regression analysis was conducted to estimate means and standard errors (SE) of the prevalent hyperglycemia for the three different groups of illness duration for each survey. The P for trend was calculated using the median value for the prevalent hyperglycemia for each survey round between the KNHANES I (1998) and VI (2014). All analyses were performed using SAS, and the critical value for P was set at α = 0.05 in two-tailed tests.