Although spirometry results can be interpreted differently depending on the reference equation used, there are no established criteria for selecting reference equations as part of the special health examinations for Korean workers. Thus, it is essential to examine the current use of reference equations in Korea, quantify their impact on result interpretation, and propose reference equations suitable for Korean workers, while also considering the environmental conditions of special health examination facilities.

The 213,640 results from the special health examination database were analyzed to identify changes in the ratio of measured values to reference values of lung capacity in Korean workers with changes in age or height, and changes in the agreement of interpretations with the reference equation used. Data from 238 organizations that participated in the 2018–2019 quality control assessment by the Korea Occupational Safety and Health Agency were used to identify the spirometer model and reference equations used in each special health examination facility.

Korean special health examination facilities used six reference equations, and the rate of normal or abnormal ventilatory diagnoses varied with the reference equation used. The prediction curve of the Global Lung Function Initiative 2012-Northeast Asian (GLI2012) equation most resembled that of the normal group, but the spirometry model most commonly used by examination facilities was not compliant with the GLI2012 equation. With a scaling factor of 0.95 applied to the Dr. Choi equation, the agreement with the GLI2012 equation was > 0.81 for men and women.

We propose the GLI2012 equation as reference equation for spirometry in Korean workers. The GLI2012 equation exhibited the most suitable prediction curve against the normal lung function group. For devices that cannot use the GLI2012 equation, we recommend applying a scaling factor of 0.95 to the Dr. Choi equation.

Since the night time work was introduced as a ‘harmful factor’ for the worker's special health examination (WSHE) in 2014, the validation of the questionnaire used for screening gastrointestinal (GI) disorder has not been conducted. The purpose of this study is to verify the validity of the questionnaire using the data of specific health screening cluster.

We used WSHE screening data for 3 years, from 2014 to 2016, in health screening cluster. The subjects who had received upper GI endoscopy in opportunistic screening and WSHE simultaneously regardless of the results of the questionnaire were selected. We tested the validity of the questionnaire using upper GI endoscopy as a gold standard.

This study was conducted on 5,057 examinees in 2014, 8,352 examinees in 2015, and 10,587 examinees in 2016. The validity of the questionnaire for each year was as follows: sensitivity 12.3% (95% confidence interval [CI], 11.1–13.4), specificity 88.6% (95% CI, 87.2–90.1), accuracy 41.1% (95% CI, 39.8–42.5) in 2014, sensitivity 5.9% (95% CI, 5.2–6.5), specificity 93.6% (95% CI, 92.7–94.4), accuracy 38.6% (95% CI, 37.6–39.6) in 2015, sensitivity 6.0% (95% CI, 5.4–6.5), a specificity of 9.42% (95% CI, 93.4–95.0), accuracy of 34.2% (95% CI, 33.3–35.1) in 2016. In generally, questionnaire showed sensitivity of 10%, specificity of 90%, and accuracy of 40%.

Despite the purpose of WSHEs aiming to identify target disease early, the sensitivity of the questionnaire for GI disease was too low as 10%. The reasons for this are the problem of the question itself, and the problem of ambiguous target disease. In the future, the questionnaire should be improved to meet the purpose of the WSHE, and further correction of the target disease should be made.

This study aimed to document the trend in blood lead levels in Korean lead workers from 2003 until 2011 and blood lead levels within each of the main industries.

Nine years (2003–2011) of blood lead level data measured during a special health examination of Korean lead workers and collected by the Korea Occupational Safety and Health Agency were analyzed. Blood lead levels were determined by year, and a geometric mean (GM) was calculated for each industry division.

The overall GM blood lead level for all years combined (n = 365,331) was 4.35 μg/dL. The GM blood lead level decreased from 5.89 μg/dL in 2003 to 3.53 μg/dL in 2011. The proportion of the results ≥30 μg/dL decreased from 4.3% in 2003 to 0.8% in 2011. In the “Manufacture of Electrical Equipment” division, the GM blood lead level was 7.80 μg/dL, which was the highest among the industry divisions. The GM blood lead levels were 7.35 μg/dL and 6.77 μg/dL in the “Manufacturers of Rubber and Plastic Products” and the “Manufacture of Basic Metal Products” division, respectively.

The blood lead levels in Korean lead workers decreased from 2003 to 2011 and were similar to those in the US and UK. Moreover, workers in industries conventionally considered to have a high risk of lead exposure also tended to have relatively high blood lead levels compared to those in other industries.