Unconsciousness and amnesia after cross-body electric shocks not involving the head-A prospective cohort study.

INTRODUCTION: Little is known about how electrical current passes through the human body except that it follows the physical rule of least resistance. Whether organs remote from the shortest route of the current can be affected is unknown, as different types of tissue vary in resistance. This may explain why some people exposed to electrical injury report symptoms from the central nervous system (CNS). In this study, we examined the association between exposure to cross-body electrical current and immediate CNS symptoms. MATERIAL AND METHODS: In a prospective cohort study, we followed 6960 members of the Danish Union of Electricians for 26 weeks using weekly questionnaires. We identified 2356 electrical shocks, and for each shock we asked whether the exposure was cross-body or same-side. We excluded those who reported exposure to the head as well as those who could not report the entry and exit points of the current. We examined two outcomes: becoming unconscious or having amnesia of the event. We use percentages to describe the data and logistic regression to analyze the results. RESULTS: We found that unconsciousness and amnesia following electric shocks were rare events (0.6% and 2.2%, respectively). We found an increased risk of reporting unconsciousness and amnesia in those exposed to cross-body electrical shock exposure compared to those with same-side exposure (Odds Ratio 2.60[0.62 to 10.96] and Odds Ratio 2.18[0.87 to 5.48]). CONCLUSION: Although the outcomes investigated are rare, we cannot rule out a possible effect on the CNS when persons are exposed to cross-body electrical current even though it does not pass through the head.

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.

Neurological symptoms and disorders following electrical injury: A register-based matched cohort study.

INTRODUCTION: Electric shocks may have neurological consequences for the victims. Although the literature on the neurological consequences of electric shocks is limited by retrospective designs, case studies and studies of selected patient groups, previous research provides some evidence of a link between electric shocks, and diseases and symptoms of the central nervous system (CNS)(e.g. epilepsy, migraine and vertigo) and the peripheral nervous system (PNS)(e.g. loss of sensation, neuropathy and muscle weakness). This study aims to employ a register-based, matched cohort study, to investigate whether individuals demonstrate a greater risk of neurological diseases and symptoms of the CNS or PNS in the years following an electrical injury. MATERIALS AND METHODS: We identified 14,112 electrical injuries over a period of 19 years in two Danish registries, and matched these with three different groups of persons in a prospective matched cohort study: (1) patients with dislocation/sprain injuries, (2) patients with eye injuries and (3) persons employed in the same occupation. Year of injury, sex and age were used as matching variables. The outcomes we identified comprised neurological disorders and central or peripheral nervous system symptoms that covered a range of diagnoses in the Danish National Patient Register. The associations were analysed using conditional logistic regression for a range of time periods (six months to five years) and conditional Cox regression for analyses of the complete follow-up period (up to 20 years). RESULTS: For victims of electric shock, the CNS sequelae we identified included an increased risk of epilepsy, convulsions, abnormal involuntary movements, headache, migraine and vertigo. We also identified an uncertain, increased risk of spinal muscular atrophy and dystonia, whereas we identified no increased risk of Parkinson's disease, essential tremor, multiple sclerosis or other degenerative diseases of the nervous system. For victims of electric shock, the PNS sequelae we identified included an increased risk of disturbances of skin sensation, mononeuropathy in the arm or leg and nerve root and plexus disorders. We also identified an uncertain, increased risk of facial nerve disorders, other mononeuropathy, and polyneuropathy. CONCLUSION: Our results confirm that electrical injuries increase the risk of several neurological diseases and symptoms of the CNS or PNS in the years following the injury. Most often the diseases and symptoms are diagnosed within the first six months of the injury, but delayed onset of up to 5 years cannot be ruled out for some symptoms and diagnoses. Some of the conditions were rare in our population, which limited our ability to identify associations, and this warrants cautious interpretation. Therefore, further studies are needed to confirm our findings, as are studies that examine the mechanisms underlying these associations.

Electricians' Health After Electrical Shocks: A Prospective Cohort Study.

OBJECTIVES: To examine whether demographic and health factors are associated with risk of electrical shocks and compared mental and physical health before and after an electrical shock. METHODS: A 6-month cohort study of 6960 electricians involved weekly questionnaires regarding exposure to electrical shocks, and health. We examined the association between health and demographic factors and the risk of eventual electrical shocks and health before and after a shock. RESULTS: Youth and poor health were associated with risk of shocks. Reporting of numbness, cramps/spasms, tremors, tinnitus, dizziness, and flashbacks increased in the week of the shock, but only tinnitus and flashbacks persisted, as other symptoms receded. Severity, high voltage, cross-body exposure, wet entry/exit points, and direct current as well as health worries and/or neuroticism increased some estimates. CONCLUSION: Electrical shocks are common, but rarely result in health effects.

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.

Incidence and immediate consequences of electrical shocks among Danish electricians: a cohort study.

OBJECTIVES: The health-related consequences of electrical shocks are mostly studied in patients from selected cohorts in hospital burn units, by making internal comparisons of subgroups, but without comparing them to unexposed individuals, or considering information regarding the preinjury health of the injured persons. Often, little is known about the details of the electrical shocks. Our purpose was to do a longitudinal study of Danish electrical workers, to monitor exposure to electrical shocks weekly over a 6-month period and to determine whether these shocks have short-term, health-related consequences. DESIGN: Prospective cohort study with weekly measurements. SETTING: Members of the Danish Union of Electricians. PARTICIPANTS: Of the 22 284 invited, 6960 electricians (31%) participated in the baseline data collection, and the participation rate in the weekly follow-up ranged from 61% to 81% during the 6 month follow-up. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was an electrical shock and secondary outcomes were the immediate health-related consequences of the shocks. RESULTS: A total of 2356 electrical shocks were reported by 1612 (23%) of the participants during the 26-week follow-up. Alternating current and voltage below 1000 V were the most common forms of electricity. In most cases, the fingers/hands were the entry and exit points, but many were unable to specify the exit point. The participants categorised 73% of the electrical shocks as 'not at all severe', and most of the shocks did not cause any immediate physical damage. However, flashbacks were more common than physical consequences. Only a few of the participants contacted health services following an electrical shock, and even fewer were absent from work. CONCLUSION: Nearly one-fourth of Danish electricians experienced one or more electrical shocks during a 26-week period, but most of the shocks are not perceived as severe, and have only limited immediate consequences.

Mental disorders following electrical injuries-A register-based, matched cohort study.

INTRODUCTION: Electrical injuries happen every day in homes and workplaces. Not only may these injuries cause physical damage and disability, they may also cause mental disorders. The aim of this study was to investigate if persons with an electrical injury suffer from mental disorders in the following years. MATERIAL AND METHODS: In a prospective matched cohort design, we identified 14.112 electrical injuries in two Danish registries and matched these with persons with dislocation/sprain injuries or eye injuries, respectively, as well as with persons from the workforce from the same occupation, using year of injury, sex and age as matching variables. We identified possible outcomes in terms of mental diagnoses in the Danish National Patient registry, based on literature, including reviews, original studies and case-reports as well as experiences from clinical praxis. The associations were analyzed using conditional cox- and logistic regression. RESULTS: We found that the following of the examined outcomes were associated with exposure to an electrical injury compared to the matched controls. Some of the outcomes showed the strongest associations shortly after the injury, namely 'mental disorders due to known physiological condition', 'anxiety and adjustment disorders', and especially the 'Post Traumatic Stress Disorder (PTSD)' subgroup. The same pattern was seen for 'Depression' although the associations were weaker. Other conditions took time to develop ('Somatoform disorders'), or were only present in the time to event analysis ('other non-psychotic mental disorders' and 'sleep disorders'). The findings were consistent in all three matches, with the highest risk estimates in the occupation match. CONCLUSION: Electrical injuries may result in mental disorders, both acute and several years after. However, the absolute risk is limited as most of the outcomes are rare.

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.

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.

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.

Salivary cortisol and depression in public sector employees: cross-sectional and short term follow-up findings.

INTRODUCTION: Increased cortisol levels have been suggested to play a role in the development of depression. An association has been shown in some studies but not consistently. The timing of an association is uncertain, and long-term follow-up studies may miss associations in narrower time windows. In the present study, we examined the association of several cortisol measures and depression in a repeated cross-sectional and short-term follow-up design. Depression was assessed by both self-reported symptoms of depression and clinical interviews. METHOD: In 2007, 10,036 public sector employees received a questionnaire along with salivary cortisol test tubes for home administration. Morning (30min after awakening) and evening (2000h) salivary samples were collected. Questionnaires and valid saliva samples were returned from 3536 employees. Approximately 3.6 months later a subsample of the participants collected three morning saliva samples (at awakening, 20min and 40min after awakening) plus an evening sample (2000h); participants with high baseline scores of self-reported depressive symptoms, burnout and perceived stress were invited to a standardized interview (SCAN) to detect clinical depression; and the symptom questionnaire was repeated for subsample participants. The study was repeated in 2009 with questionnaires and salivary test tubes (n=2408). In four cross-sectional and two short-term follow-up analyses odds ratios of depressive symptoms and of clinical depression were estimated by logistic regression for morning, evening, mean and the difference between morning and evening cortisol (slope). For the subsample, awakening response (CAR) and area under the curve (AUC) cortisol measures were calculated. We adjusted for sex, age, income, education, family history of depression, physical activity and alcohol consumption. RESULTS: None except one of the measures of salivary cortisol were associated with self-reported depressive symptoms or clinical depression, neither in the four cross-sectional analyses nor in the two short term follow-up analyses. E.g. in 2007, the adjusted odds ratios (OR) of depressive symptoms by a one unit increase in morning and evening cortisol (ln(nmol/litre saliva)) were 1.01 (95% CI: 0.88-1.17) and 1.05 (0.93-1.18), respectively. The one exception was significant at p=0.04 and was considered as due to chance. CONCLUSION: In this large study, salivary cortisol was not associated with self-reported symptoms of depression or with clinical depression.

A two-year follow-up study of salivary cortisol concentration and the risk of depression.

Stress is a suspected cause of depression. High cortisol concentration, a biomarker of an activated stress response, has been found in depressed patients. The aim of this study was to determine if a high level of salivary cortisol is a risk factor of depression. In 2007, we enrolled 4467 public employees. Morning and evening salivary cortisol concentration were measured for each participant. Participants reporting high levels of depressive, burnout, or stress symptoms, assessed by questionnaires were assigned to a psychiatric interview. In this interview 98 participants were diagnosed with depression and subsequently excluded. Two years later in 2009, 2920 participants who had provided at least one valid saliva cortisol measurement at baseline participated at follow up. The psychiatric interviews were repeated and 62 cases of newly onset depression were diagnosed. Odds ratios of depression were estimated for every 1.0nmol/l increase in morning, evening, and daily mean cortisol concentration, as well as for the difference between morning and evening cortisol concentration. The risk of depression decreased by increasing daily mean cortisol concentration and by increasing difference between morning and evening concentrations, while morning and evening cortisol concentrations were not significantly associated with depression. The adjusted odds ratios for 1.0nmol/l increase in morning, evening, and daily mean cortisol concentration were 0.69 (95% CI: 0.45, 1.05), 0.87 (95% CI: 0.59, 1.28), and 0.53 (95% CI: 0.32, 0.90), respectively. The adjusted odds ratio for 1.0nmol/l increase in difference between morning and evening concentration were 0.64 (95% CI: 0.45, 0.90). This study did not support the hypothesis that high salivary cortisol concentration is a risk factor of depression, but indicate that low mean salivary cortisol concentration and a small difference between morning and evening cortisol concentration may be risk factors of depression.

Work-unit measures of organisational justice and risk of depression--a 2-year cohort study.

OBJECTIVES: The aim of this study is to analyse if low justice at work, analysed as aggregated workplace means, increases the risk of depression. METHODS: A total of 4237 non-depressed Danish public employees within 378 different work units were enrolled in 2007. Mean levels of procedural and relational justice were computed for each work unit to obtain exposure measures that were robust to reporting bias related to depression. Two years later in 2009, 3047 (72%) participated at follow-up. Those reporting high levels of depressive, burn-out or stress symptoms were assigned to a psychiatric diagnostic interview. In the interview 58 cases of new onset depression were identified. Depression ORs by work unit level of procedural and relational justice were estimated by multivariable logistic regression accounting for established risk factors for depression. RESULTS: Working in a work unit with low procedural justice (adjusted ORs of 2.50, 95% CI 1.06 to 5.88) and low relational justice (3.14, 95% CI 1.37 to 7.19) predicted onset of depression. CONCLUSIONS: Our results indicate that a work environment characterised by low levels of justice is a risk factor for depression.

A two-year follow-up study of risk of depression according to work-unit measures of psychological demands and decision latitude.

OBJECTIVES: The aim of this study was to examine if high psychological demands and low decision latitude at work increase the risk of depression. METHODS: In 2007, 4237 non-depressed Danish public employees within 378 different work units were enrolled in the study. Mean levels of psychological demands and decision latitude were computed for each work unit to obtain exposure measures that were robust to reporting bias. In 2009, 3046 (72%) participated at follow-up, and those reporting high levels of depressive, burnout or stress symptoms went through a psychiatric interview by which 58 cases of new onset depression were diagnosed. Odds ratios (OR) of depression for different levels of work unit mean psychological demands and decision latitude were estimated by logistic regression taking established risk factors into account. RESULTS: The OR for depression according to psychological demands was 1.07 [95% confidence interval (95% CI) 0.42-2.49] for every unit of change on a 5-point scale. The corresponding OR for decision latitude was 1.85 (95% CI 0.55-6.26). No interactive effects of psychological demands and decision latitude were observed. CONCLUSION: These findings suggest that low decision latitude may predict depression, but confidence intervals are wide and findings are also compatible with no increased risk.

Salivary cortisol and sleep problems among civil servants.

OBJECTIVE: The present study used information from a field study conducted among 4489 civil servants (70% women) in Denmark in 2007. The purpose was to examine the association between sleep problems and salivary cortisol by using a cross-sectional design with repeated measures in a subsample three-month later. METHODS: Sleep problems during the past night and the past 4 weeks were assessed by a self-administered questionnaire on overall sleep quality, disturbed sleep, sleep length and awakening problems. Saliva samples were collected in a single day, using cotton tubes, 30 min after awakening and again at 2000 h. A subsample of 387 participants collected saliva samples three-month later at awakening, +20 min and +40 min after awakening and at 2000 h. We adjusted for confounders related to sampling time, life style and personal characteristics, socioeconomic status and work aspects. RESULTS: Sleep problems during the past four weeks were associated with low morning and evening saliva cortisol concentrations: [-3.1% per score of disturbed sleep (p=.009); and -4.7% per score of awakening problems (p<.001)]. Whereas sleep problems were not related with slope (the morning to evening change in cortisol levels). Awakening problems predicted lower cortisol (-7.51% per score; p=.003) three-month later. Cortisol awakening response (CAR) and slope three-month later were significantly associated with disturbed sleep (-7.84% and -8.24%) and awakening problems (-6.93). Area under the curve (AUC(morning)) increased with disturbed sleep (3.77%). CONCLUSION: Surprisingly, low morning cortisol was associated with increased sleep problems during a four-week period prior to sampling among 4066 Danish civil servants. At follow-up three-month later, those with sleep problems had a flattened cortisol profile. Those with awakening problems also had low salivary cortisol in general.

Effects of psychosocial work factors on lifestyle changes: a cohort study.

OBJECTIVE: To evaluate the effect of the demand-control-support model, the effort-reward imbalance model, and emotional demands on smoking, alcohol consumption, physical activity, and body mass index. METHODS: This is a 2-year prospective cohort study of 3224 public sector employees. Measures were assessed with questionnaires. Multiple regression analyses were used to predict changes in lifestyle factors. RESULTS: Low reward predicted smoking, low-decision latitude predicted being inactive, and high demands predicted high-alcohol consumption but only for men at follow-up even after controlling for potential confounders. There were no other significant findings in the expected direction except for some of the confounders. CONCLUSIONS: We found only limited and inconsistent support for the hypothesis that a poor psychosocial work environment is associated with an adverse lifestyle.

Are risk estimates biased in follow-up studies of psychosocial factors with low base-line participation?

BACKGROUND: Low participation in population-based follow-up studies addressing psychosocial risk factors may cause biased estimation of health risk but the issue has seldom been examined. We compared risk estimates for selected health outcomes among respondents and the entire source population. METHODS: In a Danish cohort study of associations between psychosocial characteristics of the work environment and mental health, the source population of public service workers comprised 10,036 employees in 502 work units of which 4,489 participated (participation rate 45%). Data on the psychosocial work environment were obtained for each work unit by calculating the average of the employee self-reports. The average values were assigned all employees and non-respondent at the work unit. Outcome data on sick leave and prescription of antidepressant medication during the follow-up period (1.4.2007-31.12.2008) was obtained by linkage to national registries. RESULTS: Respondents differed at baseline from non-respondents by gender, age, employment status, sick leave and hospitalization for affective disorders. However, risk estimates for sick leave and prescription of antidepressant medication, during follow-up, based on the subset of participants, did only differ marginally from risk estimates based upon the entire population. CONCLUSIONS: We found no indications that low participation at baseline distorts the estimates of associations between the work unit level of psychosocial work environment and mental health outcomes during follow-up. These results may not be valid for other exposures or outcomes.

Does outdoor work during the winter season protect against depression and mood difficulties?

OBJECTIVE: At temperate latitudes, 1-5% of the population suffer from winter depression; during winter, mood difficulties tend to increase but may be alleviated by bright light therapy. Unlike indoor workers, outdoor workers are exposed to therapeutic levels of sunlight during winter. We hypothesized that outdoor work may protect against mood difficulties and depression. METHOD: We studied this hypothesis among 2910 civil servants from Århus, Denmark, who participated in a survey in January-February 2009. Mental symptoms (N=422) defined a common case category that we broke down into two parts: depression (N=66) and mood difficulties but no depression (N=356). A total of 222 controls were also sampled from the study population. All 644 participants reported the extent of outdoor work. RESULTS: The confounder-adjusted odds ratio (OR) of mood difficulties showed a decreasing trend by increasing hours of outdoor work of borderline statistical significance. The OR was 0.63 [95% confidence interval (95% CI) 0.34-1.18)] for those working outdoors for >2 hours a day. No such effect was suggested for depression. CONCLUSION: Our study is limited by its cross-sectional design and low statistical power but nevertheless suggests that outdoor work during winter may protect against mood difficulties. If this finding holds true it may have significant impact on workers' health as well as public health in general. Therefore, further studies are recommended.

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.

[Late sequelae following electrical accidents]. / Senfølger efter elulykker.

A literature review of non-acute pain, neurological and psycho-neurological impairments in relation to electrical accidents is performed. Pain in extremities is frequent. Neurological and psycho-neurological symptoms can arise days or months after an electrical accident. The causal mechanisms are not known. The best known non-organic effect is post-traumatic stress disorder. The existing knowledge of long-term consequences of electrical accidents is generally based on cases and patient summaries. There is serious lack of longitudinal studies describing delayed or progressive non-acute symptoms.