Diabetes screening in South Korea: a new estimate of the number needed to screen to detect diabetes

Abstract

Background/Aims: The Korean Diabetes Association (KDA) guidelines recommend adults aged ≥ 40 years and adults aged ≥ 30 years with diabetes risk factors for diabetes screening. This study aimed to determine the age threshold for diabetes screening in Korean adults. Methods: This study was based on the analyses of Korean adults aged ≥ 20 years using the Korea National Health and Nutrition Examination Survey (KNHANES) and the National Health Insurance Service-National Sample Cohort (NHIS-NSC). To evaluate screening effectiveness, we calculated the number needed to screen (NNS). Results: NNS to detect diabetes decreased from 63 to 34 in the KNHANES and from 71 to 42 in the NHIS-NSC between the ages of 30-34 and 35-39. When universal screening was applied to adults aged ≥ 35, the NNS was similar to that of adults aged ≥ 40. Compared to the KDA guidelines, the rate of missed screening positive in adults aged ≥ 20 decreased from 4.0% to 0.2% when the newly suggested screening criteria were applied. Conclusions: Universal screening for adults aged ≥ 35 and selective screening for adults aged 20 to 34, considering diabetes risk factors, may be appropriate for detecting prediabetes and diabetes in South Korea.

Screening for Prediabetes and Diabetes in Korean Nonpregnant Adults: A Position Statement of the Korean Diabetes Association, 2022

“…Therefore, the Committee of Clinical Practice Guidelines of the KDA performed a study to determine the age thresholds for diabetes screening to provide evidence for screening guidelines using the KNHANES 2016 to 2020 and the NHIS-NSC 2012 to 2017 [ 22 ]. The analysis, using two large datasets representative of Korea’s general population, was reliable in that it analyzed relatively recent data.…”

“…Notably, the NNS markedly decreased from 63 in the group aged 30 to 34 years to 34 in the following age group of 35 to 39 years in the KNHANES and from 71 to 42 for the same age groups in the NHIS-NSC, respectively ( Fig. 2 ) [ 22 ], Therefore, it seems plausible to perform universal screening for diabetes or prediabetes in adults aged ≥35 years.…”

“…For adults aged 20 to 34 years, NNS was calculated according to the presence of diabetes risk factors using the KNHANES ( Table 2 ) [ 22 ]. Among the suggested risk factors for diabetes according to the KDA guideline, data on overweight or obesity (defined as body mass index [BMI] ≥23 kg/m 2 for overweight and ≥25 kg/m 2 for obesity), family history of diabetes, hypertension, and dyslipidemia were available in the KNHANES.…”

“…Based on these results, assuming universal screening for individual over the age of 35 and selective screening for adult aged 20 to 34 with risk factors, the total NNS for diabetes was 18 and the rate of missed screening positivity was 0.2% [ 22 ]. This could significantly reduce the rate of missed screening positive of 4%, calculated based on previous KDA guideline, without significantly increasing the NNS from 16 to 18 [ 22 ].…”

“…In addition, the committee calculated the NNS for the detection of prediabetes or diabetes in all age groups [ 22 ]. The NNS for prediabetes or diabetes was lower in all age groups than the NNS for diabetes only, and there was no sharp decrease between the age groups (the NNS value from the 20 to 24-year age group to the ≥75-year age group ranged from 1 to 8 in the KNHANES and 3 to 10 in the NHIS-NSC.…”