Return-to-Work According to Impairment type among occupationally injured workers in Korea

This study examined the association between return-to-work and impairment type. Database of the Korea Workers' Compensation and Welfare Service was used to identify disabled persons; and return-to-work information was obtained from the Korea Employment Information Services database. The study participants were 79,328 persons who received Workers' compensation and who were confirmed as disabled during 2009-2011. Logistic regression was used to analyze the association between return-to-work and impairment type, adjusted by age, sex, impairment severity, pre-injury businesses size, and pre-injury occupational category. Compared to injuries of the upper limbs, the odds ratio of return-to-work was 0.63 (95% CI, 0.60-0.65) for injuries involving the lower limbs, 0.62 (95% CI, 0.59-0.66) for the spine, 0.75 (95% CI, 0.66-0.86) for the eyes, 0.98 (95% CI, 0.77-1.25) for the oral cavity, 0.44 (95% CI, 0.37-0.53) for the ears, 1.02 (95% CI, 0.83-1.25) for the figure, 0.75 (95% CI, 0.72-0.79) for pain, and 0.36 (95% CI, 0.32-0.41) for neuropsychiatric impairment. These findings indicate that impairment type influences return-to-work rates.ope

A new disability rating method according to the job using the Korean Academy of Medical Science disability guideline

The purpose of this study was to develop a disability rating scale according to job classification using the Korean Academy of Medical Society (KAMS) guidelines. All jobs were categorized based on their level of physical activity and professional skills. The KAMS guidelines were used for the impairment rating. We modified the California Schedule for rating permanent disabilities. The differences were plotted to compare between the impairment rate and the job-adjusted disability rate. The KAMS job-adjusted disability rates were then compared to the McBride and workers' compensation rates. A total of 1,206 occupations were classified into 44 groups. The occupational disability indexes were rated on a scale of 1 to 7. The differences in the McBride disability rates varied inconsistently from 0% to 35%, while the differences in the KAMS disability rates were between 0% and 18%. The KAMS disability rates were slightly higher than the McBride disability rates for the upper extremities, but were lower for the lower extremities and internal organs. This is the first Korean job-adjusted disability rating method. There are several limitations, but its impairment rating is more scientific and reflects the current Korean occupational environment.ope

Two cases of lung cancer in foundry workers.

Background : Iron and steel foundry workers are exposed to various toxic and carcinogenic substances including crystalline silica, polycyclic aromatic hydrocarbons, and arsenic. Studies have been conducted on lung cancer in iron and steel founding workers and the concentration of crystalline silica in foundries; however, the concentration of crystalline silica and cases of lung cancer in a single foundry has never been reported in Korea. Therefore, the authors report two cases of lung cancer and concentration of crystalline silica by the X-ray diffraction method. Case presentation : A 55-year-old blasting and grinding worker who worked in a foundry for 33 years was diagnosed with lung cancer. Another 64-year-old forklift driver who worked in foundries for 39 years was also diagnosed with lung cancer. Shot blast operatives were exposed to the highest level of respirable quartz (0.412 mg/m3), and a forklift driver was exposed to 0.223 mg/m3. Conclusions : The lung cancer of the two workers is very likely due to occupationally related exposure given their occupational history, the level of exposure to crystalline silica, and epidemiologic evidence. Further studies on the concentration of crystalline silica in foundries and techniques to reduce the crystalline silica concentration are required.ope

Comparison of Cardiovascular Disease Characteristics According to the Employment Status among Emergency Department Patients

employed population in comparson with the non-employed group. Methods: The study subjects were patients aged 20~65 from 3 university based hospital emergency centers and a structured questionnaire were used for comparing the characteristics of cardiovascular disease according to employment status. Multivariate logistic regression was used to analyze the association between employment status and cardiovascular disease risk factors. Results: Among the patients, 573 people were employed (482 males, 91 females) and 251 were nonemployed (117 males, 134 females). Compared to the non-employed group, the employed group was distinctive in that it contained patients of younger age, had a male dominant gender distribution, and a higher proportion of smoking and drinking patients. The employed group was less likely to be previouslydiagnosed with diabetes, hypertension, chronic renal failure, cardiovascular disease, or cerebrovascular disease. The employed group was generally more stressed out but there was no significant differences in sleeping time. Infarction was more frequent in the employed group, but hemorrhage was more frequent in the non-employed group. According to the multivariate logistic regression analysis results, the odds ratio of drinking and stress was 1.89(95% CI: 1.25~2.86) and 2.68(95% CI: 1.80~3.99) respectively. Conclusions: Infarction was more frequent in the employed group. Drinking and stress were also more frequent in the employed group. The results of this study don’t necessarily mean that stress and drinking are more important than other risk factors but, it means stress and drinking control are more important in the employed group compared to the non-employed group.ope

Allergic Diseases and Multiple Chemical Sensitivity in Korean Adults

PURPOSE: Multiple chemical sensitivity (MCS) is a clinical syndrome representing multi-organ and psychological symptoms caused by chronic exposure to various chemicals in low concentrations. We evaluated the prevalence and related factors of MCS targeting Korean adults using the Quick Environmental Exposure and Sensitivity Inventory (QEESI©). METHODS: A total of 446 participants were recruited from Severance Hospital. Participants underwent a questionnaire interview including questions on sociodemographic factors, occupational and environmental factors, allergic diseases, and the QEESI©. Among them, 379 participants completed the questionnaire and the QEESI©. According to the QEESI© interpretation results, participants were divided into very suggestive (VS) group and less suggestive (LS) group. RESULTS: The estimated prevalence of MCS was higher in allergic patients than non-allergic participants (19.7% and 11.3%, respectively, P=0.04). In the multivariate logistic regression analysis, ages of 30-39 (OR, 2.94; 95% CI, 1.25-6.95) and those of 40-49 (OR, 2.51; 95% CI, 1.02-6.21) were significantly related to MCS compared to those aged less than 30 years. Female sex (OR, 2.16; 95% CI, 1.11-4.18), experience of dwelling in a new house (OR, 2.05; 95% CI, 1.04-4.03), and atopic dermatitis (OR, 1.95; 95% CI, 1.04-3.69) were also significantly related to MCS. However, only age of 30-39 in the allergic group was significant in the stratified analysis. CONCLUSIONS: The estimated prevalence of MCS was higher among allergic patients than non-allergic participants. People with experience of dwelling in a new house and atopic dermatitis were more at risk of being intolerant to chemicals. Further studies to provide the nationally representative prevalence data and clarify risk factors and mechanisms of MCS are required.ope

(An) international comparative analysis of the cancer control laws : policy implications for the provement of the cancer control act of K

보건정책관리학과/석사[한글]우리나라는 고령화 추세에 따라 암으로 인한 경제사회적 부담이 계속 증가하고 있다. 대장암, 전립샘암 등 서구형 암이 많아지는 등 암발생의 양상이 변화하고 있고, 암예방·진단·치료기술은 급격히 발달하고 있다. 세계보건기구(WHO)는 국가 차원의 암관리 기준을 마련하여 회원국에게 권장하고 있고, 미국이나 일본은 수십년 이상 암관리사업을 체계적으로 추진해오고 있다. 국내외적인 상황 변화에 따라 새로운 차원의 국가 암관리사업을 전개하기 위해서는 기존 암관리법을 비롯한 암관리 관련 법령 및 사업에 대한 개선방안을 제시할 필요가 있다. 이에 WHO의 암관리기준과 공중보건법 이론에 따라 우리나라, 미국, 일본의 암관리 법령 및 사업 현황을 비교·분석하여 우리나라 관련 법령에 대한 시사점을 도출코자 하였다. 분석은 WHO 기준에 따라 암정책 수립 및 인프라 부문, 암예방, 암조기검진, 암진단치료, 암완화의료, 암연구, 암등록 등 7개 영역으로 나누었다. 우리나라는 암관리법, 국립암센터법, 국민건강보험법, 국민건강증진법 등이, 미국은 공중보건서비스법(Public Health Service Act)이, 일본은 암대책기본법이 주된 분석 대상이 되었다. 분석 결과는 다음과 같다. 암정책수립 및 인프라 구축 부문의 경우 사업 성과평가 내용과 시민단체 등의 이해관계자가 국가암관리사업의 기획·수행·평가에 참여하는 것을 제도화하고, 근거 중심의 암정보를 수집·제공하는 내용을 암관리법에 별도 조항으로 포함시킬 필요성이 있다. 암예방 부문에서는 암예방 시책을 추진해야 한다는 선언적 조항을 포함시키되, WHO의 권고안대로 암예방 사업을 만성질환 예방사업의 일환으로추진해야 한다. 암조기검진 부문에서는 국민들을 상대로 조기검진에 대한 이해를 높여 수검률을 향상시키고, 조기검진이 가능한 암종을 확대하며, 비용효과적인 검진방법을 개발할 필요성이 있다. 이들 조치는 유관 법령의 개정 없이 연구과제 발주나 시범사업 추진 등 행정조치만으로도 가능하다. 암진단·치료의 세계적 추세는 암진료에 대한 다학제적 접근과 암임상시험 활성화를 통한 진단·치료율 향상으로 요약할 수 있기 때문에 우리나라도 다기관 암임상연구 지원을 강화가 할 필요가 있다. 암완화의료 부문의 경우 완화의료 내용 및 절차, 그리고 완화의료 전문기관에 관한 지원 내용을 암관리법에 반영할 필요가 있다. 암연구는 암정복추진연구개발사업을 이행성 연구, 다기관 공동 암임상연구, 근거를 구명하는 전통의학적 연구 등으로 특성화하고, 암등록사업은 병기 및 치료내용별 생존율 등을 산출하는 등 국민이 체감할 수 있는 암통계정보를 생산해야 한다. 이들 조치는 입법이나 법 개정 없이 예산사업으로 개선할 수 있는 내용이다. 우리나라 암관리는 궁극적으로 암 등 특정 질환 중심이 아니라 만성질환의 공통적인 위험요인을 차단하는 생활습관 개선 방향으로 나갈 필요가 있다. 금연, 균형잡힌 식생활, 절주, 예방접종, 운동, 체중조절 등 생활습관의 변화는 암뿐만 아니라 다른 만성질환도 동시에 예방하기 때문에 비용효과적이다. 따라서 장기적으로는 암 등 특정 질환 예방·관리 중심에서 만성질환에 공통적인 위험요인을 차단하기 위한 생활습관 개선으로 우선 순위를 옮길 필요가 있으며, 이는 국민건강증진법을 기본법적 성격으로 개정하면 이루어질 수 있다. 또한 가장 큰 단일 암 위험요인인 담배가 국민 건강에 미치는 해악을 고려할 때 규제 위주의 조치를 취하는 것이 당연하다. 따라서 담배사업법 등을 폐지하고 가칭 ‘담배관리법’이라는 단일법으로 통일시키거나 국민건강증진법에 포함시키도록 하되 그 내용은 WHO 담배규제기본협약(FCTC)이 권고하는 내용과 부합되도록 한다. 한편 우리나라의 암관리 관련 법령은 법령간 통일성이 유지되도록 개선할 필요가 있다. 국립암센터는 그 주된 기능이 국가암관리사업을 지원하는 것이므로 국립암센터가 별도의 독립된 법을 가지기보다는 국가 암관리 내용을 담고 있는 암관리법에 흡수되는 것이 타당하다. 암조기검진 내용은 건강검진기본법에서, 진단치료의 경우에는 주로 진료비 경감 등의 문제를 다루므로 국민건강보험법이나 의료급여법 등에서 다루는 것이 법적 통일성에서 바람직하며, 완화의료 관련 내용은 궁극적으로는 암뿐만 아니라 AIDS 등 치명적 질환까지 완화의료에 포함시킬 수 있도록 독립된 법으로 개정할 필요가 있다. [영문]A sharp increase in ageing population is one of the main reasons that cancer burden is on the steady rise in Korea. In terms of cancer incidence, Korea is following western countries as more and more people are diagnosed with colorectal, prostate and thyroid cancers. The World Health Organization or WHO has drawn up a guideline for cancer control at the national level, disseminating it to member countries. The U.S. and Japan have given top priority to the cancer control policy, implementing the programs for more than four decades. Korea needs to learn much from these two countries' cancer control experiences. This study was devised to provide the government with some policy implications for improving Korea's Cancer Control Act and related programs by making a comparative analysis of the cancer control related laws of Korea, U.S. and Japan. The analysis was based upon the public health law theories and WHO's cancer control guidelines including the Fifty-eighth World Health Assembly's Resolution on Cancer Prevention and Control (WHA58.22). I have grouped cancer control contents into the following seven fields in accordance with the WHO guideline: 1) establishment of cancer policy and infrastructure; 2) cancer prevention; 3) early detection; 4) diagnosis and treatment; 5) palliative care; 6) cancer research, 7) cancer registration and statistics. The targets of analysis were the Cancer Control Act, the National Cancer Center Act, the Health Insurance Act and the Health Promotion Act in Korea, the Public Health Service Act in the U.S., and the Cancer Control Act in Japan. Following are the conclusions that I have reached by analysing the related laws and programs of the three countries; In the field of developing cancer policy and infrastructure, a clause institutionalizing stakeholders' participation in the development, implementation and evaluation of cancer control policy and programs needs to be added to the Cancer Control Act. The Act also needs to include another clause that provides for the collection, analysis and dissemination of the evidence-based cancer information. In the area of cancer prevention, a nominal clause declaring the government's dedication to cancer prevention should be shown in the Act and the national cancer prevention programs are to be carried out as part of the government's comprehensive chronic diseases prevention programs. In the field of early detection, the government should try to boost the target people's participation rate by enhancing the general people's understanding of the importance of early detection in cancer. It also should try to increase the number of early-detectable cancers and develop the cost-effective screening technologies by promoting research activities. Since the best outcome in cancer treatment could be realized through a combination of multidisciplinary approach and evidence-making clinical research, the government should support multi-institutional clinical cancer trials among the medical community specializing in cancer. The Act should provide for the definition and contents of palliative care in more detail and procedures for supporting the palliative care organizations which are high in demand but low in supply in Korea. In order to differentiate the National R&D Program for Cancer Control from other National R&D ones, it needs to give its priority to translational research, multi-institutional clinical trials, and the verification of the effects of traditional medicine in cancer. Cancer registration program should meet the people's needs by producing cancer patients' survival rates by stage and treatment procedure. Cancer control policies should be incorporated into the life-style modification policies which aim to address the risk factors common to most of the chronic diseases. In that sense, the Health Promotion Act of Korea should be revised as a basic law regulating almost all kinds of chronic diseases in the long run. The current Tobacco Industry Act should be repealed and one single law such as the so-called th Basic Law for Health Promotion should regulate the tobacco related matters, reflecting WHO's FCTC recommendations. Finally, some subjects that Korea's cancer related laws stipulate overlap with one another. Therefore, these laws need to be reorganized according to their inherent functions. For example, the National Cancer Center (NCC) Act should be incorporated into the Cancer Control Act because the NCC was established as a central agency for implementing the national cancer control programs which are regulated mainly by the Cancer Control Act.ope

A study of the estimation for cardiovascular function and blood pressure using the photoplethysmographic signal

의료공학협동과정 의공학전공/석사[한글] 본 연구에서는 광센서를 이용하여 수집된 PPG 신호를 사용하여 혈압을 추정할 수 있는 방법을 제안한다. 혈압의 변동은 혈액량의 변동과 저항 성분의 변동으로 구성된다. 그리고 PPG 신호는 혈압의 파형과 유사함을 보이며 혈관의 수축과 이완의 기점에 대해서도 유사한 변화를 보인다[32]. 즉 광원이 피부에 투과되어질 때 파형의 맥동성분은 동맥혈관에서 심장의 수축과 이완에 영향을 받으며, 직류성분은 심장의 이완동안 혈관 내에 잔류하는 혈액을 의미한다. 따라서 실험에서 시간의 함수 형태로 획득된 PPG 신호를 분석하여 심장의 출력성분(DC)과 저항성분(AC)을 구분함으로써 심혈관의 기능과 혈압을 추정할 수 있는 근거를 제공한다. 실험은 우선적으로 동물 실험을 통해 혈압과 PPG 신호와의 상관관계를 조사하였으며 발견되어진 관계를 바탕으로 1차적 임상실험을 통하여 재확인하였다. 이후 2차적 임상실험을 통해 PPG 신호와 온도·압력과의 상관성을 알아보았고 마지막으로 모든 실험을 바탕으로 PPG 신호로부터 심혈관계의 기능과 혈압 추정을 하였다. 상관관계 분석은 중회귀분석법을 사용하였다. 본 연구에서 동물실험과 임상실험 1은 개의 꼬리와 피검자의 손가락에서 측정되었다. 그리고 두개의 요소가 온도와 압력에 표준화 되어진 각각의 PPG 신호로부터 유도되었다: 혈액량 신호, 맥파 신호. 혈압은 이 두 신호의 변화율에 의해 추정되어진다. 두 신호와 혈압과의 중회귀분석에서 상관성은 동물실험에서 수축기 혈압에 대해 0.924±0.060, 이완기 혈압에 대해 0.931±0.460, 임상실험 1에서 수축기 혈압에 대해 0.722±0.090, 이완기 혈압에 대해 0.831±0.113임을 확인하였다(p<0.001). 임상실험 2도 피검자의 손가락에서 측정되었는데 이 때 혈액량 신호와 맥파 신호는 각 시기에 대해 온도와 압력으로부터 유도되었다. 두 신호와 혈액량 신호와 맥파 신호의 중회기분석에서 상관성은 수축기 혈액량 신호에 대해 0.835±0.155, 이완기 혈액량 신호에 대해 0.844±0.145, 맥파 신호에 대해 각각 0.767±0.120, 0.770±0.121임을 보여준다. 이 결과는 이동형 감시 장치에 쓰이는 센서의 형태에 의해 측정되어지는 비표준화된 PPG 신호를 통한 혈압의 추정의 가능성을 제시한다. PPG 신호는 소동맥계로부터 혈압을 제시하는 근거를 제공한다. 표준화된 PPG 신호가 장기적으로 획득되어질 때 혈액량과 맥파의 변화추이는 획득되어질 수 있고 혈압이 증가되어지는 현상을 예측할 수 있다. 비표준화된 PPG 신호는 온도와 압력에 의해 표준화 시켜야한다는 이상의 결론으로부터 기존의 커프에 의한 혈압측정법의 단점을 보완하고 환자의 편의성과 접근성을 유도하는 시스템을 개발할 수 있을 것이다. [영문]This study proposes a method to estimate blood pressure(BP) from the photoplethysmographic(PPG) signal. Blood pressure consists of the change of blood volume and the resistance. Preciding studies present the PPG signal resembles the BP wave and varies, as does the BP wave, with vasodilator and vasoconstrictor drugs on the circulation[32]. When the light source transmits the skin, just the pulsation factor is affected by cardiac contraction and relaxation and the non-pulsation factor means the remained blood in the vessel during cardiac relaxation. Therefore, we distinguished the cardiac output and the blood vessel resistance by analyzing the PPG signal. This process furnished the bases of the cardiovascular function(CVF) and BP. In the animal experiments, we first found the correlations between BP and PPG signal, In the first clinical experiments, we reconfirmed the relationships. Next we found correlations between PPG signal and temperature and between PPG signal and pressure with the second clinical experiments. Finally, by the experiments, we could estimate CVF and BP from the PPG signal by the multi-regression analysis. In the current study, the animal and the first clinical experiments were performed on the index tales and on the index fingers, and two parameters were derived from each PPG signal which is normalized with temperature and pressure. BP was estimated by the level of the variability of the two signals. In multi-regression analysis, we confirmed that the correlation coefficients between BP and the two signals are 0.92±0.060 for systolic BP(SBP) and 0.931±0.460 for diastolic BP(DBP) from the animal experiments. In case of the first clinical experiments, the correlation coefficients are 0.722±0.090 for SBP and 0.831±0.113 for DBP(p<0.01). The second clinical experiments was also performed on the index fingers, then BV signal and PW signal were changed by temperature and pressure. In multi-regression analysis, the correlation coefficients between the signals show 0.835±0.155 for systolic BV signal, 0.844±0.145 for diastolic BV, and 0.767±0.120 for PW signal(p<0.01). This result presents a possibility of estimation of BP with the PPG signals(without normalization) that are acquired from sensors of mobile monitoring equipment. The PPG signal furnishes an information for present BP of the arterial system. We are able to get transitions of BV and PW when the normalized PPG signal is acquired during a long term. This process can predict the increase of BP. From the result mentioned above, the PPG signal has to be normalized to temperature and pressure. Then we can develop the system which complements the weak points of existent cuff BP measurement and give a convenience and a good access.ope

비관혈적 혈압측정: PPG 파형기반의 추정 및 검증

Dept. of Biomedical Engineering/박사Photoplethysmograph (PPG) is an optical measurement technique that can be used to detect blood volume (BV) changes in the micro vascular bed of tissue. It has widespread clinical application, with the technology utilized in commercially available medical devices. PPG waveform is believed to have significant information regarding the patient’s cardiovascular condition which has not been fully utilized in the current clinical practice.The objective of the current study is to assess the feasibility of using multiple features derived from the finger PPG waveform as markers of BP. The specific objectives are; first, to study the change in PPG waveform during BP change from patients in emergency room and intensive care unit based on a blood flow model and to evaluate their potentials as non-invasive indicators of cardiovascular diseases (CVDs), second, to evaluate the potential use of the finger PPG waveform derived BP as a non-invasive indicator of BV and vascular resistance (VR) by investigating its association with progressive change in the central BV and the total peripheral resistance (TPR) induced by cardiac stimulants, third, to investigate the propriety of using normalized PPG derived the finger PPG waveform to track variations in contact force (CF) change at measurement area and progressive changes in PPG waveform induced by forced gradual cooling and heating, forth, to develop an automated method of detecting BP from the finger PPG waveform and evaluate the reliability of the measurement by direct comparison with the BP measured from clinical non-invasive blood pressure (NIBP) equipment.The results from current study clearly show the possibility of finger PPG waveform as a noninvasive determine tool for BP change. BP detection model were verified by the relationship study, which involved change of cardiovascular status from a group of healthy human subject that constituted blood pressure change and a group of healthy animal subject that induced via commonly used cardiac stimulants. The results from these studies have supported that morphological features derived from the finger PPG waveform could be very useful for detecting the change in central BP, and the trends of features might be possible to identify not only the local BV change but also the VR change in peripheral vasculature. The relationship between effects of environment and the finger PPG waveform was confirmed that CF and skin surface temperature (SST) changes in groups of healthy subjects produced the progressive PPG waveform change. The clinical study focused on long-term comparison and has shown that morphological features of the finger PPG waveform could be potential markers of BP change, which may help to patients who are interested in monitoring their daily BP.In terms of clinical application, this approach is best way to identify BP change as easily as possible, because we can apply the long-term monitoring possibility of BP measurement system. In this perspective, the finger PPG waveform-based technique may prove to be extremely valuable detection technique of BP. The technique proposed in the current study may be applied in home and mobile healthcare phase, so that whenever and wherever the patient are, BP assessment can be more convenient with very simple monitoring procedures. When the simple, comfortable and totally noninvasive BP measurement is required, PPG waveform will be the ideal application for continuous BP monitoring of the patient.ope

산업재해 환자의 직장복귀와 직업유지에 관련된 요인

보건학과INTRODUCTION Since 2007 in Korea, the annual number of workers with occupational injuries and diseases was more than 90,000, and the injuries and diseases result in considerable negative impacts. Return-to-work (RTW) is an effective way to prevent and reduce negative effects. Although there are researches and policies promoting RTW of workers, post re-entry situation of returned workers were not well understood. For successful RTW, it is necessary to understand the current situation of job retention along with re-entry after occupational injuries and diseases. Furthermore, researches on impacts of RTW type and period on job retention are also required. Therefore, the objective of this study is to understand the current situation and explore the related factors of RTW including both re-entry and retention, also, this study aims to investigate the impacts of RTW type and period on job retention. METHODS The Panel Study of Workers’ Compensation Insurance including data from 2,000 systemically sampled workers who had finished recuperation in 2012 was used in this study. Impacts of sociodemographic, work-related, and accident related factors were examined according to the workers’ RTW status and retention status. In the first analysis, the relationship between RTW (returned to original work or reemployed) and the factors were examined by logistic regression analyses. In the second analysis, the relationship between 24-month retention according to RTW type and other factors was examined by logistic regression analyses. In the third analysis, the relationship between job retention, regardless of period, according to RTW type and other factors was examined by Cox’s proportionalhazards model. In the fourth analysis, the relationship between job retention according to RTW period was examined. RESULTS The RTW rate in this study was 80.5% (original work: 35.9% and reemployed: 44.7%). In total workers, age, perceived health status, recuperation period, and disability rating were related to RTW. In workers returned to original work, age, education level, industry, perceived health status, accident type, recuperation period, rehabilitation service utilization, and maintenance of a relationship with employer were related to RTW. In reemployed workers, industry, perceived health status, recuperation period, disability rating, and maintenance of a relationship with employer were related to RTW. RTW type was related to 24-month job retention with OR for non-retention of 3.88 (2.86-5.28) in reemployed workers. In total workers, age, education level, perceived health status, accident type, and RTW consultation were related to 24-month retention. In workers returned to original work, age, education level, perceived health status, and recuperation period was related to 24-month retention. In reemployed workers, education level and perceived health status were related to 24-month retention. In the survival analyses, RTW type was related to job retention with HR for non-retention of 2.66 (2.11-3.35). RTW period was related to job retention with HR for non-retention of 3.03 (1.52-6.04) in the workers returned in 13 – 24 months and 5.33 (2.14-13.25) in the workers returned after 24 months. DISCUSSION In this study, there are notable results which can be considered in policy implementation. First, higher non-retention rate in the second year in returned to original work group was shown. Therefore period for fund supporting, which is now up to 1 year, needs to be considered for extension. Second, lower job retention probability in reemployed group was shown. Therefore, protection policies for the reemployed workers or benefits to the employers are needed. Third, RTW period was shown as a good prognostic factor for job retention. Therefore, shortening recuperation period along with delay in RTW should be considered. CONCLUSION Job retention is an important process in RTW. Considering that reemployed workers and workers with RTW period of more than 13 months are at more risks for non-retention, policies encouraging return to original workplace, protecting reemployed workers, and promoting early RTW should be considered.open박

Learning mechanisms of strategic alliances

Thesis (doctoral)--서울대학교 대학원 :경영학과 국제경영 전공,2001.Thesis (doctoral)-