Perceived stress among adolescents as a marker for future mental disorders: A prospective cohort study.

AIM: The mental health problems of adolescents are important in relation to their future health and life course. The aim of this study was to investigate perceived stress in adolescence as a marker for later mental disorders. METHODS: The data consisted of a combination of questionnaire and register data for 11,929 adolescents. Perceived stress was measured using Cohen's Perceived Stress Scale divided into low, moderate and high perceived stress. Mental disorder was identified using the ICD-10 codes for Mental and Behavioural Disorders classified into whether the adolescents were diagnosed or not. Logistic regression was used to examine the prospective association between perceived stress and mental disorders during about 12 months of follow-up, including the adolescents self-rated health, sex and parental education. RESULTS: In total, 247 adolescents (2.1%) were diagnosed with a mental disorder during follow-up. The perceived stress of the adolescents was associated with mental disorders, yielding two-fold higher odds of developing a mental disorder for adolescents reporting moderate perceived stress and six-fold higher odds among adolescents reporting high perceived stress in the adjusted model. CONCLUSIONS: Adolescents with high levels of perceived stress were more likely to develop a mental disorder. Interventions to reduce perceived stress among adolescents could therefore potentially help to identify groups at high risk for later mental disorders.

The importance of adverse childhood experiences for labour market trajectories over the life course: a longitudinal study.

BACKGROUND: Transitioning from school to work is important in influencing people's trajectories throughout their life course. This study investigated the extent to which adverse childhood experiences (ACEs) were associated with differences in labour market trajectories for young adults in the context of a Nordic child care regime with low levels of child poverty. METHODS: Information on labour market participation, educational events, and public transfer records was recoded into seven state spaces for each month between ages 16 and 32 for a cohort of Danish adolescents born in a rural county in 1983 (N = 3373). Cluster analysis of the sequences using the optimal matching algorithm was used to identify groups with similar trajectories. Multinomial regression was used to assess the association between self-reported ACEs and cluster membership, taking gender and family of origin into account. RESULTS: 'In employment' was the state space in which the young adults spent the most time over their early life courses (mean: 85 out of 204 months; 42%). Cluster analysis identified three clusters. Cluster 3 was most distinct, where the mean time 'outside the labour market' was 149 months (73%), and only 17 months (8%) were spent 'in employment'. Cumulative ACEs increased the probability of being included in Cluster 3 (OR: 1.51). Experiencing parental divorce (OR: 3.05), witnessing a violent event (OR: 3.70), and being abused (OR: 5.64) were most strongly associated with Cluster 3 membership. CONCLUSIONS: Labour market trajectories among adolescents with a higher number of ACEs consisted of more time outside the labour market, compared to adolescents who had experienced fewer adversities. The lasting consequences of childhood adversity should be taken more into account in welfare policies, even in countries such as Denmark, with high social security levels and high-quality universal childcare.

Not just a research method: If used with caution, can job-exposure matrices be a useful tool in the practice of occupational medicine and public health?

The recent editorial by Dr Susan Peters "Although a valuable method in occupational epidemiology, job-exposure matrices are no magic fix" ably describes the strengths and limitations of job-exposure matrix (JEM) approaches in occupational epidemiology research (1). In addition to their use in research, we would like to add that JEM may also be of use in compensation and surveillance efforts in occupational health. JEM could assist the compensation process by supporting the assessment of relevant exposures related to specific health conditions (2). The potential usefulness of a JEM as a decision tool for compensation of work-related musculoskeletal disorders has been examined (3). Because occupational diseases are often under-recognized, another practical application is using a JEM to screen for occupational exposures as part of health surveillance. Use of JEM to screen for asbestos and wood dust exposure in the clinical setting has shown promising results (4-6). By summarizing multiple exposures at a job level (7), JEM may also assist policy-makers in setting priorities for hazards and controls at work, as well as occupational practitioners to target prevention efforts and direct the conduct of more precise exposure measures to particular jobs. Sharing JEM across different countries may be useful in providing estimates of exposures across larger populations to calculate global burden of disease related to occupational exposure. The JEMINI (JEM InterNatIonal) initiative was launched to explore the possibility of developing international JEM that could be used across countries (8). Beginning with physical (biomechanical) exposures, this open group has started homogenizing job coding systems and comparing some available JEM. Estimating differences in the level of exposure between countries will require much more work, without guaranteed success. As Peters mentioned, many limitations exist in the use of JEM. Users of JEM must consider the source of exposure data - expert assessments, data collected from individual workers, or environmental sampling. The coding of occupations is time consuming and can introduce error (9), and more testing of and comparison with automated job coding systems is needed (10). JEM reflect an "average" level of exposure within a job at the expense of individual variation. At population level, JEM can offer a useful estimate of exposures. If used at an individual level in a clinical or compensation setting, JEM cannot replace the professionals involved in exposure assessment but may help them focus their action more effectively on complex situations that require their expertise. In conclusion, these JEM developed for research might also be used as a public health tool, provided that their limitations are properly taken into account. References 1. Peters S. Although a valuable method in occupational epidemiology, job-exposure matrices are no magic fix. Scand J Work Environ Health 2020;46:2314. https://doi.org/10.5271/sjweh.3894 2. Kerbrat J, Descatha A. (The recognition of health consequences of difficult working conditions in France and its evaluation with the use of a job-exposure matrix). Arch Mal Prof Environ. 2018;79:493500. https://doi.org/10.1016/j.admp.2017.12.001 3. Fadel M, Valter R, Quignette A, Descatha A. Usefulness of a job-exposure matrix « MADE ¼ as a decision tool for compensation of work-related musculoskeletal disorders. Eur J Public Health 2019;29:86870. https://doi.org/10.1093/eurpub/cky274 4. Lorentz E, Despreaux T, Quignette A, Chinet T, Descatha A. (Screening of occupational exposure to asbestos and silica by job-exposure matrix among patients with lung cancer and mesothelioma). Rev Mal Respir. 2019;36:108895. https://doi.org/10.1016/j.rmr.2019.08.006 5. Imbernon E, Goldberg M, Spyckerell Y, Steinmetz J, Bonenfant S, Fournier B. (Use of a job-exposure matrix for the screening of occupational exposure to asbestos). Rev Epidemiol Sante Publique 2004;52:717. https://doi.org/10.1016/S0398-7620(04)99018-9 6. Carton M, Bonnaud S, Nachtigal M, Serrano A, Carole C, Bonenfant S, et al. Post-retirement surveillance of workers exposed to asbestos or wood dust: first results of the French national SPIRALE Program. Epidemiol Prev. 2011;35:31523.   7. Guéguen A, Goldberg M, Bonenfant S, Martin JC. Using a representative sample of workers for constructing the SUMEX French general population based job-exposure matrix. Occup Environ Med. 2004;61:58693. https://doi.org/10.1136/oem.2003.010660 8. Descatha A, Evanoff BA, Andersen JH, Fadel M, Ngabirano L, Leclerc A, et al. JEMINI (Job Exposure Matrix InterNatIonal) Initiative: a Utopian Possibility for Helping Occupational Exposure Assessment All Around the World? J Occup Environ Med. 2019;61:e3201. https://doi.org/10.1097/JOM.0000000000001631 9. Petersen SB, Flachs EM, Svendsen SW, Marott JL, Budtz-Jørgensen E, Hansen J, et al. Influence of errors in job codes on job exposure matrix-based exposure assessment in the register-based occupational cohort DOC*X. Scand J Work Environ Health 2020;46:25967. https://doi.org/10.5271/sjweh.3857 10. Buckner-Petty S, Dale AM, Evanoff BA. Efficiency of autocoding programs for converting job descriptors into standard occupational classification (SOC) codes. Am J Ind Med. 2019;62:5968. https://doi.org/10.1002/ajim.22928.

Coping strategies in adolescence and labour-market participation in young adulthood: A prospective birth cohort study.

Aims: The aim of this study was to investigate whether coping strategies in adolescence (14-15 years of age) were associated with labour-market participation (LMP) in young adulthood (25-26 years of age) and whether the association differed by sex. Methods: A birth cohort from the former county of Ringkjoebing, Denmark, consisting of 2826 individuals, comprised the study population. In 2004, the study population completed a questionnaire from which information about coping and covariates were gathered. Coping strategies were measured using five sub-scales of the Brief COPE Scale, which were combined into two overall coping strategies: active coping and avoidant coping. Ten years later, the participants were followed for a 52-week period in a register on social benefits. Logistic regression was applied to data, with adjustment for covariates: sex, parents' socio-economic status (education and income) and self-rated health. Results: A total of 2203 (78%) participants were categorised as high LMP at follow-up. No significant associations were found between active coping in adolescence and LMP in 2014/2015. For avoidant coping, in the fully adjusted model, medium-level avoidant coping was associated with higher odds (odds ratio (OR)=1.02 (95% confidence interval (CI) 0.83-1.25) of high LMP. For low avoidant coping, the OR was 1.37 (95% 1.07-1.75). For both coping strategies, sex did not modify the association. Conclusions: Findings showed that avoidant coping was significantly associated with high LMP. Further research is needed to investigate coping in relation to specific problem areas.

Labour market attachment among parents and self-rated health of their offspring: an intergenerational study.

BACKGROUND: Unemployment influences the individual's health, whether this effect passes through generations is less studied. The aim of this intergenerational study was to investigate whether parents' labour market attachment (LMA) were associated with self-rated health (SRH) among adolescents using preceding labour market events. METHODS: The study was performed using questionnaire data from the Danish Future Occupation of Children and Adolescents cohort (the FOCA cohort) of 13 100 adolescents (mean age 15.8 years) and their accompanying parents identified through registers. Adolescents' SRH was measured using one item from SF-36. Information on parents' LMA was obtained from a national register, analyzed on a weekly basis in a 5-year period before the adolescents completed the questionnaire. An integration indicator was calculated from an initial sequence analysis to determine how well the parents were integrated in the labour market. The association between the adolescents' SRH and parents' LMA was examined by logistic regression and an extended sequence analysis stratified on adolescents' SRH. RESULTS: Totally, 29.1% of the adolescents reported moderate SRH. The adjusted odds ratios (OR) of moderate SRH was higher among adolescents of parents with low labour market integration (OR: 1.5 95% CI: 1.3-1.6 for fathers and OR: 1.4 95% CI: 1.2-1.5 for mothers). Also, adolescents with moderate SRH had parents who were less integrated in the labour market and had more weeks on non-employment benefits compared with the adolescents, who reported high SRH. CONCLUSIONS: Unstable LMA among parents affected SRH among their adolescent children, indicating a negative effect of labour market marginalization across generations.

Do negative childhood conditions increase the risk of somatic symptoms in adolescence? - a prospective cohort study.

BACKGROUND: In order to prevent health and social problems later in life, it is important to identify childhood conditions related to the development of somatic symptoms. This prospective study expands on previous research by investigating whether negative childhood conditions are related to somatization later in life, taking other risk factors into account. This study aims to investigate whether somatic symptoms of the participants' parents, poor family functioning, or negative life events during childhood result in somatic symptoms in early or late adolescence. METHODS: The study population includes participants from the West Jutland Cohort Study who responded to the survey on their somatic symptoms at age 15 (n = 2963) and/or age 18 (n = 2341). The study also includes additional questionnaire information about the participants' poor family functioning, number of negative life events, and parental reports of somatic symptoms as well as register information about parental socioeconomic background. Generalized linear models for the binomial family were used and the results were presented as relative risks (RR) and risk differences (RD) with 95% confidence intervals (95%-CI). RESULTS: Experiencing poor family functioning at age 15 showed associations with somatic symptoms at age 15 (RR 1.75, 95%-CI, 1.43-2.14 and RD 18, 95%-CI, 11-25%) and 18 (RR 1.32, 95%-CI, 1.00-1.75 and RD 7, 95%-CI, 0.2-14%). The relative risks between poor family functioning and somatic symptoms were 2.5 for the boys at age 15 and 1.71 for the girls at age 18. Having experienced two or more negative life events up to the age of 15 was associated with reporting somatic symptoms at age 15 (RR 1.73, 95%-CI, 1.31-2.28 and RD 24, 95%-CI, 11-37%). No relative risks above 1.35 were found between parents reporting somatic symptoms and participants reporting somatic symptoms at ages 15 or 18. CONCLUSIONS: An increased awareness of the association between a poor social climate in the family and somatic symptoms may help professionals in health and educational systems prevent the development of such symptoms among adolescents.

A Quantitative General Population Job Exposure Matrix for Occupational Daytime Light Exposure.

High daytime light levels may reduce the risk of affective disorders. Outdoor workers are during daytime exposed to much higher light intensities than indoor workers. A way to study daytime light exposure and disease on a large scale is by use of a general population job exposure matrix (JEM) combined with national employment and health data. The objective of this study was to develop a JEM applicable for epidemiological studies of exposure response between daytime light exposure, affective disorders, and other health effects by combining expert scores and light measurements. We measured light intensity during daytime work hours 06:00-17:59 for 1-7 days with Philips Actiwatch Spectrum® light recorders (Actiwatch) among 695 workers representing 71 different jobs. Jobs were coded into DISCO-88, the Danish version of the International Standard Classification of Occupations 1988. Daytime light measurements were collected all year round in Denmark (55-56°N). Arithmetic mean white light intensity (lux) was calculated for each hour of observation (n = 15,272), natural log-transformed, and used as the dependent variable in mixed effects linear regression models. Three experts rated probability and duration of outdoor work for all 372 jobs within DISCO-88. Their ratings were used to construct an expert score that was included together with month of the year and hour of the day as fixed effects in the model. Job, industry nested within job, and worker were included as random effects. The model estimated daytime light intensity levels specific for hour of the day and month of the year for all jobs with a DISCO-88 code in Denmark. The fixed effects explained 37% of the total variance: 83% of the between-jobs variance, 57% of the between industries nested in jobs variance, 43% of the between-workers variance, and 15% of the within-worker variance. Modeled daytime light intensity showed a monotonic increase with increasing expert score and a 30-fold ratio between the highest and lowest exposed jobs. Building construction laborers were based on the JEM estimates among the highest and medical equipment operators among the lowest exposed. This is the first quantitative JEM of daytime light exposure and will be used in epidemiological studies of affective disorders and other health effects potentially associated with light exposure.

[Development of "MADE", a French Job exposure matrix for evaluation of biomechanical exposure]. / Développement d?une matrice emplois-expositions française (« MADE ¼) pour l'évaluation des contraintes biomécaniques.

OBJECTIVE: This paper presents the stages of development of an occupational biomechanical exposure matrix and preliminary reliability and validity indicators. METHODS: The expertise-based job exposure matrix, called "MADE" (for "difficult physical conditions and job matrix"), was developed from the French and international classification of jobs for 17 biomechanical exposures. Three pairs of investigators independently rate the frequency and intensity of exposure of each job from 0 to 5; discordant scores within pairs (mean difference >20% for each biomechanical exposure considered) were discussed collectively. Reliability was assessed by the difference between the initial ratings, the number of revised jobs, and the correlation between the two classifications (with transcoding). Validity was studied by correlating variables similar to those from existing United States and Danish matrices. RESULTS: The difference between the mean scores of the pairs was considered to be "fair" (less than one point). Of the 51 paired results studied (17 exposures - 3 pairs of investigators), four coefficients were found to be less than 0.6, and 14 were between 0.6 and 0.7. Forty-nine of the 1,169 job categories were reviewed. Correlation coefficients between the initial classification and transcoding were greater than 0.7. Correlation coefficients between the French, United States and Danish MEE variables were fair to good. CONCLUSION: An expertise-based job exposure matrix with fairly reliable indicators has been developed, opening up the prospects to improve certain some fields of public health, at both national and international levels.

Effect of grip type, wrist motion, and resistance level on pressures within the carpal tunnel of normal wrists.

Elevated carpal tunnel pressure (CTP) has been associated with carpal tunnel syndrome. This study systematically evaluated the effect of wrist motion resistance and grip type on CTP during wrist motion typical of occupational tasks. CTP during four wrist motion patterns, with and without resistance, and with and without gripping, was measured in vivo in 14 healthy individuals. CTP measured during compound motions fell between that measured in the cardinal planes of wrist flexion/extension and radial/ulnar deviation. Generally, with no active gripping there was little pressure change due to wrist angular displacement or resistance level. However, concurrent active pinch or power grip increased CTP particularly in motions including extension. CTP typically did not increase during wrist flexion, and in fact often decreased. Extension motions against resistance when employing a pinch or power grip increase CTP more than motions with flexion. Results could help inform design or modification of wrist motion intensive occupational tasks. © 2014 The Authors.

Initial non-participation and loss to follow-up in a Danish youth cohort: implications for relative risk estimates.

BACKGROUND: Initial non-participation and loss to follow-up in the Danish youth cohort Vestliv could introduce selection bias of the measured risk estimates. OBJECTIVE: To investigate the impact of initial non-participation and loss to follow-up on the validity of descriptive measures and selected estimates of relative risk. METHODS: Of the 3681 young people defining the source population, 83% answered a questionnaire at baseline in 2004. At follow-up waves in 2007 and 2010, the response rates were 71% and 64%, respectively. Relative ORs (RORs) were used to examine the impact of initial non-participation and loss to follow-up on the association between socioeconomic or personal risk factors at age 14/15 and educational attainment at age 20/21. RORs were calculated as OR (baseline population)/OR (source population) or OR (follow-up population)/OR (baseline population). RESULTS: The participants had slightly better school abilities and came more often from homes with two adults, higher income or higher educational level. These differences increased at subsequent follow-ups. The effect of initial non-participation on the ORs was modest with most RORs being close to one. Loss to follow-up led to larger variations in the RORs ranging from 0.77 to 1.62 although for most estimates, the bias was minor. None of the measured RORs were statistically different from one indicating no significant bias. CONCLUSIONS: Although certain characteristics were related to those who initially chose to participate and especially to those who participated at follow-ups, it did not have any large influence on the relative risk estimates measured in the study.

Can negative life events and coping style help explain socioeconomic differences in perceived stress among adolescents? A cross-sectional study based on the West Jutland cohort study.

BACKGROUND: Previous research suggests that perceived stress in adolescence is socially patterned, but that this relationship may depend on the measure of socioeconomic status (SES) used. This study examines if social gradients in perceived stress, negative life events, and coping exist amongst Danish adolescents, and, if life events and coping strategies can partly account for an association between SES and perceived stress. These relationships are studied separately for two different measures of SES. METHODS: Questionnaire data were collected from 3054 14-15 year old youths (83% response rate) during baseline measurement in the West Jutland birth cohort study. Parents were identified via the Central Office of Civil Registration in which the respondents are linked to their parents or guardians via their CPR-number, a personal identification number given to everyone in Denmark. The study employs data from two independent sources, adolescent self-report data (stress, life events and coping) and national registers (parental educational level, household income and confounder variables). Ordinary Least Squares regression estimated the effects of parental SES, negative life events and coping on perceived stress. Analyses were stratified by gender. RESULTS: Girls reported more perceived stress than boys. SES accounted for a small but significant amount of the variance in perceived stress. Lower parental education and lower household income were associated with higher stress levels irrespective of gender, but the social gradient was strongest amongst girls when parents' education was used to measure SES, and strongest for boys when income was used. Life events and coping were also found to be associated with SES and both mediated part of the SES-perceived stress relationship. In general, the social gradient in perceived stress was accounted for by the study variables to a higher degree among girls than among boys. CONCLUSIONS: Lower parental education and household income are associated with higher levels of perceived stress amongst Danish adolescents. Furthermore, both life events and coping appear to mediate this relation. Gender differences in the ways SES and stress are related may exist.

Cross-cultural adaption and measurement properties of the Danish version of the Shoulder Pain and Disability Index.

OBJECTIVE: To cross-culturally adapt the Danish version of the Shoulder Pain and Disability Index and to evaluate its measurement properties in terms of reliability and known-group validity. DESIGN: Test-retest study. SETTING: Outpatient Clinic of the Department of Orthopaedic Surgery, Regional Hospital Herning, Denmark. SUBJECTS: Consecutive shoulder patients referred to an outpatient clinic. METHODS: The Shoulder Pain and Disability Index was translated from English into Danish according to international guidelines. The questionnaire was posted to patients one to two weeks before their scheduled clinical examination and repeated on the day of the examination. RESULTS: A total of 65 patients with a variety of shoulder diagnoses were included in the study. No significant differences were found in scores between the first and the second questionnaire. The minimal detectable change was estimated to 19.4 points, and the intraclass correlation coefficient was 0.88 (95% confidence interval 0.83 to 0.94). Internal consistency measured by Cronbach's alpha was 0.94. The questionnaire was found to discriminate well between currently working and non-working patients. CONCLUSION: The Shoulder Pain and Disability Index provides a sensitive and reliable tool to assess pain and disability in Danish-speaking orthopaedic shoulder patients.

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.

Depression, the Val66Met polymorphism, age, and gender influence the serum BDNF level.

Brain-derived neurotrophic factor (BDNF) has been suggested as a candidate gene for depression and numerous studies have investigated the possible association between genetic variants within BDNF and depression. Clinical studies have investigated the serum BDNF levels in individuals with depression. However, few studies have combined genetic association studies with serum BDNF measurements. The purpose of the present study was therefore to perform an investigation of BDNF using 162 individuals with depression and 289 healthy individuals. All individuals returned a completed questionnaire and participated in a semi-structured diagnostic interview. The major contribution of the present study is the integration of clinical assessment of cases and control individuals, simultaneous analyses of several genetic variants, serum BDNF measurements, and information on socio-demographic variables, lifestyle, and health indicators in a statistical model. In the present study the serum BDNF levels were increased in the depressive subjects compared to control individuals. Additionally, six SNPs were successfully analyzed, but did not associate with depression. Multiple linear regression models were applied and age, depression, gender, the Val66Met polymorphism, and the interaction between Val66Met and gender were identified as significant determinants of the serum BDNF level. In conclusion, our data demonstrate that other factors than a diagnosis of depression influence the serum BDNF level and the importance of these factors should be emphasized comparing different studies.

Risk factors for neck and upper extremity disorders among computers users and the effect of interventions: an overview of systematic reviews.

BACKGROUND: To summarize systematic reviews that 1) assessed the evidence for causal relationships between computer work and the occurrence of carpal tunnel syndrome (CTS) or upper extremity musculoskeletal disorders (UEMSDs), or 2) reported on intervention studies among computer users/or office workers. METHODOLOGY/PRINCIPAL FINDINGS: PubMed, Embase, CINAHL and Web of Science were searched for reviews published between 1999 and 2010. Additional publications were provided by content area experts. The primary author extracted all data using a purpose-built form, while two of the authors evaluated the quality of the reviews using recommended standard criteria from AMSTAR; disagreements were resolved by discussion. The quality of evidence syntheses in the included reviews was assessed qualitatively for each outcome and for the interventions. Altogether, 1,349 review titles were identified, 47 reviews were retrieved for full text relevance assessment, and 17 reviews were finally included as being relevant and of sufficient quality. The degrees of focus and rigorousness of these 17 reviews were highly variable. Three reviews on risk factors for carpal tunnel syndrome were rated moderate to high quality, 8 reviews on risk factors for UEMSDs ranged from low to moderate/high quality, and 6 reviews on intervention studies were of moderate to high quality. The quality of the evidence for computer use as a risk factor for CTS was insufficient, while the evidence for computer use and UEMSDs was moderate regarding pain complaints and limited for specific musculoskeletal disorders. From the reviews on intervention studies no strong evidence based recommendations could be given. CONCLUSIONS/SIGNIFICANCE: Computer use is associated with pain complaints, but it is still not very clear if this association is causal. The evidence for specific disorders or diseases is limited. No effective interventions have yet been documented.

Incidence of work injuries amongst Danish adolescents and their association with work environment factors.

BACKGROUND: The objective was to examine the incidence of work accidents that required medical attention among Danish adolescents and to identify possible work environment factors associated with such accidents. METHODS: We collected information in two questionnaire rounds (2004 and 2007) from a birth cohort comprising all adolescents born in 1989 (n = 3,687) living in Ringkjøbing County, Denmark. The questionnaire contained items on self-reported number of accidents and number of working hours in both rounds and on work environment factors in the second round. RESULTS: Approximately 5% of the adolescents who held a job, experienced a work injury at the age of 17. This equals an incidence of 65 accidents per million working hours. Most adolescents had decent working conditions, although nearly half reported that their work was heavy, monotonous or psychologically demanding. Heavy work, high psychological demands and low social support increased the risk of experiencing work injuries after adjustment for a number of factors. CONCLUSIONS: The incidence of work injuries among adolescents appears to be higher than the incidence among their older colleagues. Lack of social support from management significantly raised adolescents' risk of experiencing a work injury. This suggests that more direct supervision may be a good way of preventing accidents in this age group.

Job strain and the risk of depression: is reporting biased?

It is unknown whether the relation between job strain and depression reflects causal characteristics of the working environment or reporting bias. The authors investigated reporting bias by analyzing individual versus work-unit measures of job strain and the risk of depressive symptoms (n = 287) and a diagnosis of depression (n = 97) among 4,291 employees within 378 work units in Aarhus, Denmark, 2007. All participants reported psychological demands and decision latitude, and the authors estimated mean values for each work unit. The odds ratios predicting depressive symptoms or a diagnosis of depression for the highest versus the lowest levels of individual, self-reported high psychological demands and low decision latitude were significantly increased above 2.5. When participants were classified by the work-unit mean levels, these associations were substantially smaller. For depressive symptoms, the odds ratios were 1.49 (95% confidence interval (CI): 0.88, 2.53) and 1.08 (95% CI: 0.84, 1.39), respectively, for psychological demands and decision latitude. For a diagnosis of depression, the odds ratios were 1.33 (95% CI: 0.57, 3.09) and 1.02 (95% CI: 0.68, 1.56), respectively, for psychological demands and decision latitude. These findings indicate that reporting bias inflates associations between job strain and the occurrence of depression, if studies rely on individual self-reports.

Does computer use pose a hazard for future long-term sickness absence?

The aim of the study was to investigate if weekly duration of computer use predicted sickness absence for more than two weeks at a later time.A cohort of 2146 frequent computer users filled in a questionnaire at baseline and was followed for one year with continuously recording of the duration of computer use and furthermore followed for 300 weeks in a central register of sickness absence for more than 2 weeks.147 participants of the 2,146 (6.9%) became first time sick listed in the follow-up period. Overall, mean weekly computer use did not turn out to be a risk factor for later sickness absence. The hazard ratio for sickness absence with weekly increase of one hour in computer use was 0.99 (95% CI: 0.99 to 1.00). Low satisfaction with work place arrangements and female gender both doubled the risk of sickness absence.We have earlier found that computer use did not predict persistent pain in the neck and upper limb, and it seems that computer use neither predicts future long-term sickness absence of all causes.