The effect of special medical examination for night shift workers and follow-up management against hypertension

Background: Special health examination is a screening program introduced in 1973 in Korea to examine health problems of workers who are regularly exposed to 177 hazardous substances and physical environments specified by the Occupational Safety and Health Act. Shiftwork was added as a risk factor in 2013. The purpose of this study was to analyze changes of hypertension status after a special medical examination and subsequent follow-up management. Methods: We used the data based on the special medical examination outcomes for night shift workers, performed at seven different health examination centers under the Korea Medical Institute (KMI) between 2014 and 2016. Workers who received special medical examinations for two consecutive years (2014–2015 and 2015–2016) were selected. A final study population of 2070 was evaluated. Results: Compared with the first-year examination, 1503 subjects (72.6%) received hypertension medication or showed improvement in blood pressure in their second-year examination. Older age (≥40s), women, larger workplaces (≥300 full-time workers), long-term workers (≥12 years), improvement in smoking habits, improvements for diabetes or dyslipidemia, normal or reduced BMI, and normal waist circumference were associated with proper management of hypertension. Conclusions: An appropriate follow-up management program should be developed to provide health management for night shift workers that need to focus on the factors identified in this study.