Unspecified pain and other soft tissue disorders following electrical injuries: a register-based matched cohort study.

OBJECTIVE: This study investigates whether individuals who have sustained an electrical injury (EI) are diagnosed with unspecified pain or pain related to the musculoskeletal system in the years following the injury. METHODS: Individuals listed in Danish registers as having sustained EIs were matched for sex, age, and year of injury in a cohort study with individuals having experienced dislocations/sprains (match 1), eye injuries (match 2), and a sample of individuals with the same occupation without a history of electrical injuries (match 3). Outcomes were unspecified pain and unspecified soft tissue disorders. Conditional logistic regression and conditional Cox regression were applied. RESULTS: We identified 14,112 individuals who sustained EIs. A higher risk of both outcomes was observed for all three matches, and was highest at the 6- and 12-month follow-ups. The risk of both outcomes was considerably higher for match 3. CONCLUSIONS: This study confirms that exposure to EIs increases the risk of being diagnosed with unspecified pain or unspecified soft tissue disorders both at short and long terms. Our results also showed that the risk of unspecified pain as sequelae is related to the severity of the injury.

Reliability and structural validity of the Danish Short 4-item version of the Center for Epidemiological Studies Depression Scale for Children (CES-DC4) in adolescents.

BACKGROUND: The 4-item version of the Center of Epidemiological Studies Depression Scale (CES-DC4) is a self-reported questionnaire used to measure depressive symptoms in adolescents, but the psychometric properties of the scale have been tested to only a limited extent. The aim of this study was to examine the reliability and structural validity of the Danish CES-DC4 in 9th graders. METHODS: Using a sample of 72 adolescents 15 to 17 years of age from five 9th grade classes, the reliability of the CES-DC4 was determined by a test-retest study at a 2-week interval. Descriptive statistics of the adolescents were presented, and internal consistency, structural validity, reliability, and agreement between tests were evaluated. The structural validity of the scale was tested by confirmatory factor analysis (CFA), and the sumscores of the test and retest were presented. RESULTS: The estimated Cronbach's α was 0.61 (95% CI 0.50; 0.71). Inter-item and item-rest correlations indicated that one of the four items (item 20) did not fit well on the scale. CFA found a one-factor model suited for the scale, but the factor loadings indicated that item 20 contributed the least to measure the factor (0.29). Sum scores ranged from 0-9 within a possible interval of 0-12. There were no signs of systematic error of the scale. Limits of Agreement (-3.01; 3.79) were broad. The standard error of measurement (SEM = 1.25 point (95% CI.1.05; 1.47)) and intraclass correlation (ICC(2,1) = 0.60 (95% CI: 0.44; 0.73)) calculations showed low reliability of the CES-DC4. CONCLUSION: This study found low reliability of the CES-DC4 with low estimates of ICC and Cronbach's α. The CES-DC4 needs revision, and removal of item 20 and adding more items from the CES-DC should be considered.

Contacts with general practitioner, sick leave and work participation after electrical injuries: a register-based, matched cohort study.

OBJECTIVE: Exposure to electrical current may cause injury with both mental and physiological consequences. This may lead to increased contacts with general practitioners (GP) and the injured person may develop reduced ability to work. We aimed to examine these outcomes in terms of work-participation, long-term sick leave and contacts with GPs. METHODS: In a matched cohort design, we identified 14 112 electrical injuries in two registries and matched these with both patients with distorsion injuries or eye injuries, and with persons from the same occupation, using year of injury, sex and age for matching. We defined the outcomes based on register information regarding contacts with GPs and public transfer income. After the injury, we determined if the person had a long-term sick leave episode during the first 6, 12 months and 5 years. We calculated work participation during the year and 5 years and the number of GP contacts in the year of the injury, the year after and 5 years after the injury and dichotomised this at twice the mean number of contacts in the study population. The associations were analysed using conditional logistic regression. RESULTS: We found increased risk for all defined outcomes, with the highest estimates in the occupation match. The risk estimates were similar over time. Adjusting for previous work participation increased the estimates slightly, whereas adjusting for previous contacts with GPs reduced the estimates. Restricting to those with at longer hospitalisation increased the estimates. CONCLUSION: Electrical injuries increase risk of long-term sick leave, low work participation and increased contacts with GPs.

Sociodemographic, personal, and disease-related determinants of referral to patient-reported outcome-based follow-up of remote outpatients: a prospective cohort study.

PURPOSE: We examined the association between sociodemographic, personal, and disease-related determinants and referral to a new model of health care that uses patient-reported outcomes (PRO) measures for remote outpatient follow-up (PRO-based follow-up). METHODS: We conducted a prospective cohort study among outpatients with epilepsy at the Department of Neurology at Aarhus University Hospital, Denmark. Included were all persons aged ≥ 15 years visiting the department for the first time during the period from May 2016 to May 2018. Patients received a questionnaire containing questions about health literacy, self-efficacy, patient activation, well-being, and general health. We also collected data regarding sociodemographic status, labour market affiliation, and co-morbidity from nationwide registers. Associations were analysed as time-to-event using the pseudo-value approach. Missing data were handled using multiple imputations. RESULTS: A total of 802 eligible patients were included in the register-based analyses and 411 patients (51%) responded to the questionnaire. The results based on data from registers indicated that patients were less likely to be referred to PRO-based follow-up if they lived alone, had low education or household income, received temporary or permanent social benefits, or if they had a psychiatric diagnosis. The results based on data from the questionnaire indicated that patients were less likely to be referred to PRO-based follow-up if they reported low levels of health literacy, self-efficacy, patient activation, well-being, or general health. CONCLUSION: Both self-reported and register-based analyses indicated that socioeconomically advantaged patients were referred more often to PRO-based follow-up than socioeconomically disadvantaged patients.

Influences of childhood family factors on depressive symptoms in adolescence and early adulthood: A Danish longitudinal study.

Aims: The study examined the timing of family socio-economic factors during early (aged 0-8 years) and late (aged 9-14 years) childhood, as well as psychosocial variables in relation to depressive symptoms at the ages of 15, 18 and 21. Methods: This prospective cohort study included 3014 young people from western Denmark. Exposure variables were equivalised household income (income), mother's educational level and mother's labour market participation (LMP), derived from registers and self-reported variables family functioning, subjective social status and negative life events. The outcome variable was depressive symptoms. Associations were analysed using logistic regression, adjusted for other exposure variables and sex. Results: In early childhood, mother's low LMP was associated with higher risk of depressive symptoms at the age of 15, whereas mother's low educational level and lower income was associated with higher risk of depressive symptoms at the age of 21. In late childhood, lower income, mother's low educational level and mother's low LMP was associated with higher risk of depressive symptoms at the ages of 15 and 21. Poorer family functioning was associated with depressive symptoms at the age of 15-21, with estimates ranging from 1.8 to 2.6. Reporting two or more negative life events were associated with depressive symptoms at the ages of 15 and 18. Conclusions: Timing of low income, mother's low educational level and mother's low LMP during childhood in relation to future depressive symptoms in the offspring appears to be of some importance in this Danish youth cohort. Family functioning and negative life events were the most stable risk factors for depressive symptoms. Results should, however, be interpreted with caution due to the risk of reverse causality.

Subjective social status is an important determinant of perceived stress among adolescents: a cross-sectional study.

BACKGROUND: Stress is an increasing public health problem, and the association between stress and subjective social status (SSS) among adolescents has received little attention. SSS in society have shown to be associated with perceived stress, but the association between SSS in school and stress has never been examined. The aim of this study was to explore the association between SSS and perceived stress in Danish adolescent boys and girls. METHODS: Data was collected in 2017 in frame of The Danish Occupation of Children and Adolescents Cohort (FOCA cohort), where Danish 9th graders (age 15/16) from 1746 schools participated in a survey (4527 girls, 3654 boys, aged 15 to 16 years). SSS in society and SSS in school were the exposure variables, and the level of perceived stress was the outcome variable. Associations between SSS in school and in society separately with perceived stress was analysed using linear regression models stratified by gender and adjusted to social and health-related factors (e.g. neighbourhood safety, home characteristics, grade meaning, homework load, self-rated health, smoking, alcohol consumption). RESULTS: The mean overall PSS score was 14.7; for girls the score was 16.3, and for boys it was 12.6. The analyses revealed a strong linear association between SSS, in both society and school, and perceived stress. The lower the SSS, the higher perceived stress. The associations were the same for both genders, but girls reported a higher level of stress than did boys. CONCLUSION: We found that girls reported a higher level of perceived stress than boys. Furthermore, we found a strong association between low SSS in society and especially SSS in school and a high level of perceived stress among Danish adolescents.

Work-related threats and violence and post-traumatic symptoms in four high-risk occupations: short- and long-term symptoms.

OBJECTIVES: To examine the associations between exposure to work-related violence and threats and subsequent PTSD among males and females in four high-risk occupations in human service work. Furthermore, we examined the modifying effect of coping style and self-efficacy. METHODS: Questionnaire data were collected in 2011 and in 2015 from 2678 employees working in psychiatric wards, in the elder sector, in special schools and in the Prison and Probation Service (PPS). Exposure to work-related violence and threats was measured in 2011, while PTSD was measured in 2011 and 2015 by the Impact of Event Scale-Revised. To assess the associations, logistic regression was conducted, adjusted for bullying, sexual harassment, negative acts, conflicts at work, other private traumas and baseline PTSD. RESULTS: There was an association between work-related threats and PTSD in 2011 and 2015. Furthermore, there was an association between work-related violence and PTSD in 2011. The associations were strongest in the PPS. Male staff had a higher risk for PTSD. Neither coping style nor self-efficacy did modify the associations between exposure to work-related violence and threats and subsequent PTSD. CONCLUSION: The prevention of PTSD following work-related violence and threats should first of all be based on reducing the risk of work-related violence. In addition, supervisors should be trained to detect symptoms of PTSD after exposure to traumatic events.

How does psychosocial stress affect the relationship between socioeconomic disadvantage and overweight and obesity? Examining Hemmingsson's model with data from a Danish longitudinal study.

BACKGROUND: Chronic stress in childhood may increase the risk of overweight and obesity in young people. Erik Hemmingsson has suggested a new obesity causation model which focuses on psychosocial stress. The aim was to examine the associations between socioeconomic disadvantage and overweight and obesity and examine if these associations attenuate, when the effect of the different domains from Eric Hemmingsson's obesity causation model were taken into account. METHODS: A longitudinal study using data from The West Jutland Cohort Study (N = 2879). Outcome was overweight and obesity combined derived from self-reported weight and height at age 15, 18, 21 and 28 years. Exposure variables were equivalised household income, educational level and labour market participation of the mother derived from registers and psychosocial variables derived from questionnaires. A three-step adjustment model using logistic regression and stratified by gender was applied. RESULTS: Mother's low educational level was associated with a 3-fold increased odds of obesity in 18 year-old-girls, which attenuated when adjusting for the domains adult distress, disharmonious family environment and offspring distress. In 28 year-old girls, a 2.5-fold increased odds of obesity was observed, which attenuated when mutual adjusted for other socioeconomic variables and attenuated even further when adjusting for all the domains. In 18-year-old boys, a 3-fold increased odds of obesity was observed which attenuated after adjustments for adult distress, disharmonious family environment and offspring distress. In 21-year old boys, a four-fold increased odds of obesity was observed that attenuated after adjustments. At age 28 years, a three-fold increased odds of obesity was observed, which vanished in the fully adjusted model. CONCLUSIONS: Our study confirms to some extent that the associations between socioeconomic disadvantage and overweight and obesity can be explained by the domains included in Erik Hemmingsson's model, although our results should be interpreted with caution. Adult distress, disharmonious family environment and offspring distress accounted for some of the association in girls, whereas in boys it was primarily offspring distress, which had the greatest impact. Young people's educational attainment can act as a buffer in the relationship between mother's lower educational level and obesity at age 28 years.

Long-term prognosis for neck-shoulder pain and disorders: a 14-year follow-up study.

OBJECTIVES: The long-term prognosis for neck-shoulder pain and disorders and the impact of shoulder exposure among former sewing machine operators were investigated in a 14-year follow-up study. METHODS: Information on neck-shoulder pain and disorders was collected by questionnaire and clinical examination at baseline in 243 female sewing machine operators and by questionnaire 14 years later. During follow-up, information on comorbidity and job exposures was obtained from registers and by linking register-based D-ISCO 88 codes with a job exposure matrix. Logistic regression analyses were performed to examine associations between neck-shoulder pain and disorders at baseline and neck-shoulder pain and physical functioning at follow-up. RESULTS: We found an association between neck-shoulder disorders at baseline and neck-shoulder pain at follow-up (OR 5.9;95% CI 1.9 to 17.7), and between neck-shoulder pain at baseline and neck-shoulder pain at follow-up (OR 8.2;95% CI 3.5 to 19.2). Associations between neck-shoulder disorders and pain at baseline and limited physical functioning at follow-up had ORs of 5.0 (95% CI 1.5 to 16.1) and 2.2 (95% CI 1.1 to 4.6), respectively. In women still working in 2008, the association between neck-shoulder pain in 1994 and in 2008 seemed to be stronger for those in jobs with high job shoulder exposure. CONCLUSIONS: The results suggest a long-term adverse prognosis for neck-shoulder pain. High job shoulder exposure can worsen this prognosis for those who continue working. This knowledge could influence the counselling given to similar workers and emphasises the need to prevent neck-shoulder pain.

Do frequent exposures to threats and violence at work affect later workforce participation?

PURPOSE: Threats and violence at work are common problems in the human service sector. It can result in physical and psychological health symptoms. The aim of this study was to examine the association between exposure to threats and violence and workforce participation in four human service sectors. METHODS: 5170 employees answered questionnaires about threats and violence in 2010 and were followed in a register for public transfer incomes for 3.5 years to identify episodes of sick leave, general workforce participation, and permanent health-related benefits. RESULTS: We found associations between exposures to threats and violence at work and workforce participation, though only a few specific types of threats and violence were associated on their own. Self-rated severity of both threatening and violent episodes was associated with overall low workforce participation, new sick leave episodes, and permanent health-related benefits. However, the latter was not statistically significant. The same pattern seems to be present in the relation between the total amount of exposure to threats and violence (threats score and violence score), respectively, and overall low workforce participation and new sick leave episodes. The threats score was also related to permanent health-related benefits. CONCLUSION: Exposure to threats and violence is associated with temporary and permanent health-related benefits as well as with low workforce participation in general, although some of the associations were not statistically significant.

Neck-Shoulder Pain and Work Status among Former Sewing Machine Operators: A 14-year Follow-up Study.

Purpose A total of 243 Danish female sewing machine operators lost their jobs in 1996 because of outsourcing. The aim was to investigate the employment status during follow-up from 1996 to 2008, and to estimate to what extent former neck-shoulder pain had an impact on later work participation. Methods Assessment of neck-shoulder pain was based on questionnaires completed in 1994. The Danish Register-Based Evaluation of Marginalization (DREAM) register was used to describe employment status during the follow-up period. Register data were explored by sequence analyses and graphics, and the association between neck-shoulder pain and work participation was analyzed by logistic regression analysis. Results In all, 987 working years were lost during follow-up, and a sequence index plot revealed interrupted and heterogeneous courses of incomes. The odds ratio between neck and shoulder pain and a work participation score less than 75% was 1.49 (95% CI 0.84-2.67). Conclusions After outsourcing of the textile industry, the former sewing machine operators had decreased work participation and frequent transitions between different income types. Previous neck-shoulder pain tended to be associated with poor work participation. The results suggest that increased attention should be to given to dismissed workers from other industries that become outsourced, especially unskilled workers with similar work-related health limitations. Additionally, we concluded that time-to-event measures in research involving employment status are insufficient because of the many transitions that take place in working life.

Work injuries among migrant workers in Denmark.

OBJECTIVES: Work migration into Denmark has increased during the recent decades, especially after the enlargement of the European Union (EU) in 2004. Whether or not migrant workers experience more work injuries than the native workforce has been debated and results are conflicting, most likely due to methodological difficulties and cultural disparities. We set out to meet these challenges using population-based work injury registers, targeting a specific and representative region in Denmark. METHODS: This population-based study used data on work injuries from an emergency department (ED) and reported injuries from the ED's catchment area to the Danish Working Environment Authority during 11 years. We calculated incidences of work injury for groups of migrant workers compared with native Danes and adjusted incidence rate ratios based on information on the complete working population. RESULTS: The incidences of work injuries among migrant workers from the new EU countries and from the rest of the world were higher compared with Danish workers and workers from the old EU countries and other Western countries. Especially migrants older than 30 years and in low-risk industries were at higher risk. Workers who had migrated recently were at even higher risk. CONCLUSIONS: We found increased risk of work injuries among migrant workers. Studying migrants in registers is a methodological challenge as some migrants are not registered, for legal or illegal reasons; thus, only a selected group is studied, but this may most likely underestimate the risk.

The association between leisure time physical activity in adolescence and poor mental health in early adulthood: a prospective cohort study.

BACKGROUND: The incidence of poor mental health (MH) is increasing in Denmark and worldwide, especially among 16-24 year olds. Low physical activity (PA) during adolescence seems to be a risk factor for poor MH in early adulthood. Among adults, it appears that a high level of PA may be protective against poor MH. We aimed to examine whether high levels of leisure time physical activity (LTPA) during adolescence reduced the risk of poor MH at age 20/21. METHODS: Prospective cohort study with data collected during 2004-2010 in the western part of Denmark. The study population was 3031 young people (age 14/15 in 2004). LTPA was the exposure variable and originates from questionnaires in 2004/2007. MH was the outcome variable and was measured at age 20/21 in 2010. MH was evaluated using a short version of the CES-DC. Logistic regression was used to analyse the associations between levels of LTPA and MH. All analyses were stratified by gender. RESULTS: 1,589 adolescents were included in the final analyses. Girls at 14/15 years of age with a low level of LTPA had an Adjusted Odds Ratio(AOR) of 1.63 (95% CI = 1.23-2.17) for poor MH as 20/21 year olds, compared to girls with a high level of LTPA. Among boys, the corresponding AOR = 1.19 (95% CI = 0.85-1.66). We found an exposure-response relationship between levels of LTPA and MH among girls, but not among boys. Girls with a reduction/persistent low level of LTPA between the ages of 15-18 had an increased risk for poor MH at age 20/21 compared to the reference group. CONCLUSIONS: Among girls, we found an association between a low level of LTPA among 14/15 year olds as well as a reduction/persistent low level of LTPA over time with poor MH at 20/21 years. We found no association between low levels of LTPA and poor MH among 14/15 year olds boys however it appears that a reduction/persistent low level of LTPA over time may have some influence on the risk of poor MH at 20/21 years. It is important to address the change in habits of LTPA during adolescence to prevent poor MH.

Effect of Psychosocial Work Environment on Sickness Absence Among Patients Treated for Ischemic Heart Disease.

INTRODUCTION: During the last decades mortality has declined in patients with coronary heart disease due to improvements in treatments and changes in life style, resulting in more people living with chronic heart disease. This implies that focus on rehabilitation and re-integration to the work-force becomes increasingly important. Previous studies among healthy workers suggest that the psychosocial working environment is associated with sickness absence. Whether the psychosocial working environment plays a role for patients with existing cardiovascular disease on return to work and sickness absence is less studied. METHODS: A cohort of patients under 67 years and treated with percutaneous coronary intervention (PCI) was established in 2006. Three months after the procedure the patients (n = 625) answered a questionnaire about their psychosocial working environment. Patients were followed in registers for the following year. We examined the association between psychosocial working environment and sickness absence at 3 months, 1 year and new sick-listings during the first year with logistic regression. RESULTS: A total of 528 patients had returned to work 3 months after the PCI, while 97 was still sick-listed. After 1 year one was dead, 465 were working and 85 were receiving health related benefits, while 74 had left the workforce permanently. A number of 106 patients were sick-listed during the whole first year or had left the workforce permanently. After the initial return to work, 90 experienced a new sickness absence during the first year while the remaining 429 did not. High work pace, low commitment to the workplace, low recognition (rewards) and low job control were associated with sickness absence at 3 months, but not after 1 year. Low job control as well as job strain (combination of high demands and low control) was associated with new sick-listings. CONCLUSION: The psychosocial working environment was associated with sickness absence 3 months after the PCI, but not 1 year after.

Psychosocial Working Environment and Risk of Adverse Cardiac Events in Patients Treated for Coronary Heart Disease.

INTRODUCTION: During the last decades a possible association between psychosocial working environment and increased risk of coronary heart disease (CHD) has been debated and moderate evidence supports that high psychological demands, lack of social support and iso-strain (the combination of high job strain and lack of social support) is associated with primary CHD. Whether psychosocial working environment plays a role as risk factor for new cardiac events and readmissions in patients with existing cardiovascular disease is less studied. METHODS: A cohort of patients <67 years treated with percutaneous coronary intervention (PCI) was established in 2006. Three months after PCI patients answered a questionnaire about their psychosocial working environment. Patients were followed in the Danish National Patient Registry and the Danish Civil Registration System for 3+ years to identify adverse cardiac events and death. We analysed the association between psychosocial working environment and adverse cardiac events by Cox Regression. RESULTS: A number of 528 patients had returned to work 12 weeks after PCI, while 97 were still sick-listed. We identified 12 deaths and 211 other events during follow-up. We found no statistically significant associations between psychosocial working environment and risk of adverse cardiac events and readmissions or mortality. CONCLUSION: The psychosocial working environment was not associated with adverse cardiac events.

Use, failure, and non-compliance of respiratory personal protective equipment and risk of upper respiratory tract infections-A longitudinal repeated measurement study during the COVID-19 pandemic among healthcare workers in Denmark.

INTRODUCTION: Upper respiratory tract infections (URTI) are common and a common cause of sick-leave for healthcare workers, and furthermore pose a threat especially for patients susceptible to other diseases. Sufficient use of respiratory protective equipment (RPE) may protect both the workers and the patients. The COVID-19 pandemic provided a unique opportunity to study the association between use of RPE and URTI in a real-life setting. The aim of this study was to examine if failure of RPE or non-compliance with RPE guidelines increases the risk of non-COVID-19 URTI symptoms among healthcare workers. METHODS: In a longitudinal cohort study, we collected self-reported data daily on work tasks, use of RPE, and URTI symptoms among healthcare workers with patient contact in 2 Danish Regions in 2 time periods during the COVID-19 pandemic. The association between failure of RPE or non-compliance with RPE guidelines and URTI symptoms was analyzed separately by generalized linear models. Persons tested positive for severe acute respiratory syndrome coronavirus 2 were censored from the analyses. The 2 waves of data collection were analyzed separately, as there were differences in recommendations of RPE during the 2 waves. RESULTS: We found that for healthcare workers performing work tasks with a risk of transmission of viruses or bacteria, failure of RPE was associated with an increased risk of URTI symptoms, RR: 1.65[0.53-5.14] in wave 1 and RR: 1.30[0.56-3.03] in wave 2. Also non-compliance with RPE guidelines was associated with an increased risk of URTI symptoms compared to the use of RPE in wave 1, RR: 1.28[0.87-1.87] and wave 2, RR: 1.39[1.01-1.91]. Stratifying on high- versus low-risk tasks showed that the risk related to failure and non-compliance was primarily associated with high-risk tasks, although not statistically significant. DISCUSSION: The study was conducted during the COVID-19 pandemic and thus may be affected by other preventive measures in society. However, this gave the opportunity to study the use of RPE in a real-life setting, also in departments that did not previously use RPE. The circumstances in the 2 time periods of data collection differed and were analyzed separately and thus the sample size was limited and affected the precision of the estimates. CONCLUSION: Failures of RPE and non-compliance with RPE guidelines may increase the risk of URTI, compared to those who reported use of RPE as recommended. The implications of these findings are that the use of RPE to prevent URTI could be considered, especially while performing high-risk tasks where other prevention strategies are not achievable.

Personal predictors of educational attainment after compulsory school: influence of measures of vulnerability, health, and school performance.

AIMS: Getting a secondary education is essential in preventing future inequalities in health and socioeconomic status. We investigated to what degree personal predictors like low school performance, high vulnerability, and poor health status are associated with not completing a secondary education in a Danish youth cohort. METHODS: This prospective study used data from a questionnaire in 2004 and register data in 2010. The study population consisted of 3053 adolescents born in 1989. Information on educational attainment from Statistics Denmark was divided into four categories: completed, still studying, dropped out, or never attained a secondary education. Data was analysed using multinomial logistic regression. RESULTS: Low grades when completing compulsory school predicted not having completed a secondary education by age 20/21 (odds ratios (OR) between 1.7 and 2.5). Low sense of coherence in childhood was associated with dropping out from a vocational education (OR 2.0). Low general health status was associated with dropping out (OR 2.2) or never attaining a secondary education (OR 2.7) and overweight was associated with never attaining a secondary education (OR 3.5). CONCLUSIONS: The study confirms the social gradient in educational attainment. Furthermore, the results indicate that factors related to the individual in terms of low school performance, low health status, and high vulnerability predict future success in the educational system. It is recommended that these high-risk groups are recognised and targeted when designing guidance and supervision programmes for youth at secondary education.

Age at menarche and pregnancy-related pelvic pain.

AIM: Menarcheal age is a predictor of several complications related to pregnancy and diseases later in life. We aimed to study if menarcheal age is a risk factor for pregnancy-related pelvic pain. MATERIAL AND METHODS: A nested case-control study was conducted within the Danish National Birth Cohort, a cohort of pregnant women, recruited during 1996-2002, and their children. In the second trimester of pregnancy the women provided information about age at menarche and potential confounders. Selection of cases (n = 2227) was based on self-reported pelvic pain during pregnancy from an interview done 6 months post-partum. The controls (n = 2588) were randomly selected among women who did not report pelvic pain. We used logistic regression analysis to calculate odds ratios (OR) for pregnancy-related pelvic pain according to age at menarche. RESULTS: In the cohort, 18.5% of all pregnant women reported pregnancy-related pelvic pain. Compared to women who were 12-14 years old at menarche, the adjusted OR for overall pelvic pain were 1.4 (95% confidence interval [CI] 1.1-1.7) in women 11 years or younger and 0.8 (95%CI 0.6-0.9) in women 15 years or older. The corresponding adjusted OR for severe pelvic pain were 1.6 (95%CI 1.3-2.0) and 0.7 (95%CI 0.6-0.9). When age was analyzed as a continuous variable, the odds for overall and severe pelvic pain decreased with 14% and 16%, respectively, for each increasing year. CONCLUSIONS: The risk of pregnancy-related pelvic pain decreased with increasing menarcheal age in an 'exposure-response' pattern. A low menarcheal age is a risk indicator and may be a risk factor for pregnancy-related pelvic pain.

Methods in measuring return to work: a comparison of measures of return to work following treatment of coronary heart disease.

PURPOSE: Methods of measuring return to work (RTW) following temporary disability are diverse. The purpose of this study was to compare different measures of RTW within a 12-month period using a well-defined population of patients treated with Percutaneous Coronary Intervention (PCI) and weekly administrative data on transfer payments. METHODS: Different RTW measures were defined based on weekly data from 12 months follow-up after PCI and agreement between definitions was expressed as Cohen's kappa. Prognostic factors for RTW were compared using logistic regression. RESULTS: Among those working before the PCI, 70 % were back to work at 6 months after the PCI and 76 % 1 year after when using cross-sectional measures and excluding those who left the workforce permanently during follow up. When using a time to event measure, 77 % experienced RTW during follow up, while only 60 % experienced RTW without recurrent sick-leave events during the following year. We found moderate to near perfect agreement when comparing the measures, with lowest agreement between the time-to-event measure without relapses compared to the other measures. When comparing prognostic factors for the different RTW outcomes, we found most associations similar in size, except from the clinical measure left ventricular ejection fraction, possibly related to recurrent sick leave. CONCLUSIONS: Different measures revealed some differences in proportions of RTW. However, high agreement between RTW-definitions was found. Choice of RTW-definitions should depend on study purpose; simple cross-sectional methods are sufficient in prediction of RTW and analysis of risk factors, while methods capturing relapses are recommended when sustainability, prognosis and vulnerability are in focus.

Electrical injury and the long-term risk of cataract: A prospective matched cohort study.

PURPOSE: Over the years, many cases of electric cataract related to severe electrical injuries have been reported. Most have been cases where the entrance or exit point of the current was on the skull or near the eyes. Still, cases of cataract have been reported where an electric current has passed through the body between two contact points remote from the eyes. This study investigates whether persons exposed to an electric current develop cataracts in the subsequent years. METHODS: We identified 14 112 persons who had received electrical injuries in two Danish registries. We matched these with patients partly with dislocation/sprain injuries and partly with persons from the workforce from the same occupation using year of accident, sex and age as matching variables in a prospective, matched-cohort design. We identified cataract as outcome (DH25, DH26 and DH28) in the Danish National Patient Registry. The associations were analysed using conditional Cox and logistic regression. RESULTS: We did not identify an increased risk of cataract following electrical injury compared to matched controls. CONCLUSION: A review of the literature clearly substantiates the occurrence of electric cataract as a consequence of electric current coming in contact with a point on the skull or near the eye. However, our results indicate that electric cataract is not a delayed-onset effect of electrical injury, in general, and do not suggest a need for cataract screening in all cases of electrical injury.