Occupational lifting predicts hospital admission due to low back pain in a cohort of airport baggage handlers.

PURPOSE: To examine if occupational lifting assessed as cumulative years as a baggage handler is associated with first-time hospital diagnosis or treatment for low back disorders. METHODS: This study is based on the Copenhagen Airport Cohort consisting of male baggage handlers performing heavy lifting every day and a reference group of unskilled men from the greater Copenhagen area during the period 1990-2012. We followed the cohort in the National Patient Register and Civil Registration System to obtain information on diagnoses, surgery, mortality, and migration. The outcomes were first-time hospital diagnosis or surgery for (1) lumbar disc herniation or (2) low back pain (LBP). RESULTS: Baggage handlers (N = 3473) had a higher incidence rate of LBP, but not of lumbar disc herniation, compared to the reference group (N = 65,702). Baggage handlers with longer employment had a higher incidence of LBP compared to baggage handlers with shorter employment. The linear association of cumulative years as a baggage handler on LBP was significantly increased with an incidence rate ratio of 1.16 (95% CI 1.07-1.25) for a 5-year increase of employment as baggage handler. CONCLUSIONS: In this large cohort study, we found an increased incidence of LBP among baggage handlers compared to the reference group with indications of a dose-response relationship between years of employment and the outcome. For baggage handlers working on the apron, the incidence was particularly increased before introduction of technical lifting equipment, suggesting that preventive measures to reduce cumulative work load may have a positive effect.

Psychoactive substances in natural and unnatural deaths in Norway and Sweden - a study on victims of suicide and accidents compared with natural deaths in psychiatric patients.

BACKGROUND: The extent of post-mortem detection of specific psychoactive drugs may differ between countries, and may greatly influence the national death register's classification of manner and cause of death. The main objective of the present study was to analyse the magnitude and pattern of post-mortem detection of various psychoactive substances by the manner of death (suicide, accidental, undetermined and natural death with a psychiatric diagnosis) in Norway and Sweden. METHODS: The Cause of Death Registers in Norway and Sweden provided data on 600 deaths in 2008 from each country, of which 200 were registered as suicides, 200 as accidents or undetermined manner of death and 200 as natural deaths in individuals with a diagnosis of mental disorder as the underlying cause of death. We examined death certificates and forensic reports including toxicological analyses. RESULTS: The detection of psychoactive substances was commonly reported in suicides (66 and 74% in Norway and Sweden respectively), accidents (85 and 66%), undetermined manner of deaths (80% in the Swedish dataset) and in natural deaths with a psychiatric diagnosis (50 and 53%). Ethanol was the most commonly reported substance in the three manners of death, except from opioids being more common in accidental deaths in the Norwegian dataset. In cases of suicide by poisoning, benzodiazepines and z-drugs were the most common substances in both countries. Heroin or morphine was the most commonly reported substance in cases of accidental death by poisoning in the Norwegian dataset, while other opioids dominated the Swedish dataset. Anti-depressants were found in 22% of the suicide cases in the Norwegian dataset and in 29% of suicide cases in the Swedish dataset. CONCLUSIONS: Psychoactive substances were detected in 66 and 74% of suicides and in 85 and 66% of accidental deaths in the Norwegian and Swedish datasets, respectively. Apart from a higher detection rate of heroin in deaths by accident in Norway than in Sweden, the pattern of detected psychoactive substances was similar in the two countries. Assessment of a suicidal motive may be hampered by the common use of psychoactive substances in suicide victims.

Accidents and undetermined deaths: re-evaluation of nationwide samples from the Scandinavian countries.

BACKGROUND: National mortality statistics should be comparable between countries that use the World Health Organization's International Classification of Diseases. Distinguishing between manners of death, especially suicides and accidents, is a challenge. Knowledge about accidents is important in prevention of both accidents and suicides. The aim of the present study was to assess the reliability of classifying deaths as accidents and undetermined manner of deaths in the three Scandinavian countries and to compare cross-national differences. METHODS: The cause of death registers in Norway, Sweden and Denmark provided data from 2008 for samples of 600 deaths from each country, of which 200 were registered as suicides, 200 as accidents or undetermined manner of deaths and 200 as natural deaths. The information given to the eight experts was identical to the information used by the Cause of Death Register. This included death certificates, and if available external post-mortem examinations, forensic autopsy reports and police reports. RESULTS: In total, 69 % (Sweden and Norway) and 78 % (Denmark) of deaths registered in the official mortality statistics as accidents were confirmed by the experts. In the majority of the cases where disagreement was seen, the experts reclassified accidents to undetermined manner of death, in 26, 25 and 19 % of cases, respectively. Few cases were reclassified as suicides or natural deaths. Among the extracted accidents, the experts agreed least with the official mortality statistics concerning drowning and poisoning accidents. They also reported most uncertainty in these categories of accidents. In a second re-evaluation, where more information was made available, the Norwegian psychiatrist and forensic pathologist increased their agreement with the official mortality statistics from 76 to 87 %, and from 85 to 88 %, respectively, regarding the Norwegian and Swedish datasets. Among the extracted undetermined deaths in the Swedish dataset, the two experts reclassified 22 and 51 %, respectively, to accidents. CONCLUSION: There was moderate agreement in reclassification of accidents between the official mortality statistics and the experts. In the majority of cases where there was disagreement, accidents were reclassified as undetermined manner of death, and only a small proportion as suicides.

Physical violence and health-related quality of life: Danish cross-sectional analyses.

BACKGROUND: The aim of this study was to evaluate the association between experienced physical violence and health-related quality of life (HRQoL) by comparing self-reported health status for individuals with and without experience of physical violence. Our hypothesis was that individuals exposed to violence would experience worse HRQoL than non-exposed individuals. We tested whether men and women and different age groups experience similar reductions in HRQoL, and the extent to which such differences might be associated with social circumstances and lifestyle conditions. Finally, we explored the HRQoL consequences of exposure to violence in a longer time perspective. METHODS: We used data from self-completed questionnaires in two Danish nationally representative, cross-sectional health interview surveys. Exposure to violence was indicated through specific survey questions (Straus' conflict tactics scale) enquiring about different types of violence during the last 12 months. Health status of respondents was elicited by the EQ-5D and SF-36 questionnaires. The health status profiles were converted to health score indexes using the Danish algorithm for EQ-5D and the revised Brazier algorithm for SF-6D. Differences in score indexes between the exposed and non-exposed individuals were explored separately for men and women using ordinary least square regression with four age categories as explanatory variables. RESULTS: In the 2000 and 2005 surveys, respectively, 4.9% and 5.7% of respondents indicated that they had been exposed to physical violence within the last 12 months. Exposure to violence was more prevalent in the younger age groups and more prevalent for men than women. Respondents exposed to violence had lower score indexes on both the EQ-5D and the SF-6D compared with the non-exposed. Respondents who reported exposure to violence in both 2000 and 2005 reported lower HRQoL than individuals who only reported exposure in one of the surveys. CONCLUSIONS: The results of this study provide evidence for an association between exposure to physical violence and reduction in health-related quality of life.

Cumulative years in occupation and the risk of hip or knee osteoarthritis in men and women: a register-based follow-up study.

OBJECTIVES: Occupational workload has been associated with an increased risk of osteoarthritis (OA), but only little research has been conducted among female workers. The objective of this study was to analyse if men and women in farming, construction or healthcare work have increased risk of developing OA of the hip or knee. METHODS: A follow-up study based on register data of the whole Danish working population in the period 1981 to 2006 followed up for hip or knee OA during 1996 to 2006. Cumulative years in occupation were calculated for assessment of dose-response relationship. Gender-specific analyses were carried out with Cox regression models using age as timescale and adjusting for calendar period, income, unemployment and previous knee injury, and done separately for hip and knee OA. RESULTS: Male floor layers and bricklayers and male and female healthcare assistants had the highest risks of knee OA, and farmers had the highest risk of hip OA. Male farmers had increased risk of hip OA already after 1-5 years in occupation (HR, 1.63) and a dose-response-related risk of hip OA (HR up to 4.22). Generally, the risk of OA increased with cumulative years in the occupation in both men and women. CONCLUSIONS: Occupations with heavy physical workload present a strong risk for hip and knee OA in both men and women, and the risks increase with cumulative years in occupation and noticeable hip OA among male farmers.

Predictors and protective factors for adolescent Internet victimization: results from a 2008 nationwide Danish youth survey.

AIM: To examine the rate of Internet victimization in a nationally representative sample of adolescents aged 14-17 and to analyze predictors and protective factors for victimization. METHODS: Data were collected for 3707 pupils in Danish schools in 2008, using a multimedia computer-based self-interviewing programme. Family characteristics, alcohol and drug abuse, exposure to physical/sexual abuse, emotional problems, social conduct and own risky Internet behaviour were included in the analyses. RESULTS: Any online victimization was reported by 27% of the adolescents, most frequently a rumour spread online (9% of boys and 15% of girls) and sexual solicitation (5% of boys and 16% of girls). Parental surveillance of adolescents' Internet use significantly reduced their risk of online victimization. Roughly half of the adolescents had met Internet acquaintances face to face, with few instances resulting in forced sex (five boys and nine girls). Female gender, parental physical violence, previous exposure to sexual abuse, alcohol abuse in the family, self-reported emotional problems and antisocial behaviour and high Internet use were all weakly and risky online behaviour strongly associated with online victimization. CONCLUSIONS: Danish adolescents are generally aware of the principles of 'safe chatting'; however, online harassment is relatively frequent, but offline victimization based on Internet acquaintances is rare.

The Danish Register of Causes of Death.

INTRODUCTION: Cause-specific mortality statistics is a valuable source for the identification of risk factors for poor public health. CONTENT: Since 1875, the National Board of Health has maintained the register covering all deaths among citizens dying in Denmark, and since 1970 has computerised individual records. VALIDITY AND COVERAGE: Classification of cause(s) of deaths is done in accordance to WHO's rules, since 1994 by ICD-10 codes. A change in coding practices and a low autopsy rate might influence the continuity and validity in cause-specific mortality. CONCLUSION: The longstanding national registration of causes of death is essential for much research. The quality of the register on causes of death relies mainly upon the correctness of the physicians' notification and the coding in the National Board of Health.

The Danish National Cohort Study (DANCOS).

INTRODUCTION: The Danish National Cohort Study (DANCOS) is a nationally representative public health survey based on linkage of information in the repeated Danish Health Interview surveys, 1986-2005, to the national Danish registers on health and welfare. It facilitates studies of self-reported health behaviour and utilisation of healthcare services by subgroups and analysis of non-response bias. RESEARCH TOPICS: DANCOS data are utilised in a variety of analyses presented here by a few examples that emphasise the impact of modifiable risk factors on public health, description of non-response bias, and the epidemiology of chronic pain and of osteoarthritis. Examples of DANCOS-based results are shown for each of the four topics. Smoking results in 24% of all deaths and, compared to other risk factors for public health, smoking accounts for the highest number of years of life lost. For non-response the mortality is higher among non-respondents than among respondents, but no significant bias on healthcare estimates can be seen. On average individuals with chronic pain had 12.8 contacts per year to the primary healthcare sector compared with 7.3 for individuals without. For osteoarthritis it is estimated that in 2020 there will be 22,600 incident cases. CONCLUSION: DANCOS is a public health survey linked with registers with many research possibilities. With this article we hope to stimulate further interest in the survey.

Register-based studies on migration, ethnicity, and health.

INTRODUCTION: Researchers in Denmark have unique possibilities of register-based research in relation to migration, ethnicity, and health. This review article outlines how these opportunities have been used, so far, by presenting a series of examples. RESEARCH TOPICS: We selected six registers to highlight the process of how migrant study populations have been established and studied in relation to different registers: The Danish Cancer Registry, the Danish Central Psychiatric Research Register, the Danish National Patient Register, the Danish National Health Service Register, the Danish Injury Register, and the Danish Medical Birth Register. CONCLUSION: Our paper documents the unique opportunities to study migration, ethnicity, and health through Danish national registers. Our examples show that in Denmark ''country of birth'' is the most commonly used measure. It renders information on whether the person is an immigrant or not, and on ethnic background. Data on migration background (i.e. refugee status vs. family reunification, etc.) is more difficult to obtain and therefore less used. It has been debated if ethnicity should be registered upon using health services; however, some consider it discriminatory. Although, we do not register ethnicity in relation to use of health care in Denmark, our possibilities of linkage between population registers and registers on diseases and healthcare utilisation appear to render the same potentials.

Risk factors for violence exposure and attributable healthcare costs: results from the Danish national health interview surveys.

AIMS: To describe the characteristics of men and women exposed to physical violence, to identify risk factors for violence exposure and to quantify the attributable healthcare costs of violence. METHODS: The Danish national health interview surveys of 2000 and 2005 included data on exposure to defined forms of physical violence over the last 12 months. Respondents who reported exposure to violence during the past year were compared with a reference group of non-exposed respondents, and data were merged with the National Health Registers. We identified risk factors for violence by logistic regression models and used OLS regression for quantification of attributable healthcare costs of violence, including somatic and psychiatric admissions, outpatient contacts, prescriptions and primary health services; and analyzed intimate partner violence separately. RESULTS: Young age, being divorced and drinking more than the recommended amount of alcohol per week were risk factors for violence both for men and women. Total annual healthcare costs, adjusted for age and deliveries, were 787 euros higher on average for women exposed to violence than for non-exposed women, mainly related to psychiatric treatment. For women, no significant cost differences existed between victims of partner violence and non-victims. The total healthcare costs were not higher for exposed men than for non-exposed men, but male victims of partner violence incurred significantly higher costs. CONCLUSIONS: Primarily due to costs of psychiatric treatment, male and female victims of violence had higher total healthcare costs than non-exposed people. Whether mental health problems increase the risk of violence exposure or violence is a particular risk factor for health problems cannot be assessed by cross-sectional data alone.

Socioeconomic differences in perinatal health and disease.

INTRODUCTION: The Danish Medical Birth Register has been used extensively in conjunction with other national registers to examine different aspects of socioeconomic differences in perinatal health outcomes. Here, we review some recent findings. RESEARCH TOPICS: Socioeconomic differences were observed in stillbirth, preterm birth, birthweight, congenital anomalies, and infant death. The patterns varied according to the health outcome and measure of socioeconomic position, but also according to the time period and the country under study. Our review also shows how many different strategies have been used to examine the influence of socioeconomic factors on perinatal health. CONCLUSION: Danish register data is an invaluable source of information on socioeconomic differences in perinatal health. Danish registers continue to provide excellent opportunities for research and surveillance in this area.

Violence, a risk factor for poor mental health in adolescence: a Danish nationally representative youth survey.

AIMS: To analyze mental health associations between youth's exposure to physical violence outside the home and at home, including witnessing domestic violence, and to describe gender differences in the associations. METHODS: A multimedia computer-based survey among a nationally representative sample of 6,200 9th grade pupils included data on violence victimization, symptoms of anxiety and depression, psychosocial and health behaviour factors. Analyses included gender stratified cross-tabulations and logistic regressions. RESULTS: Direct associations were found for both sexes between anxiety and depression and exposure to mild and severe physical violence both outside the home and at home. Adjusted for possible confounding factors, associations for severe violence exposure both at home and outside the home were found only among girls; odds ratio (OR): 2.4 [1.3-4.7]) and OR: 3.0 [1.1-8.6], respectively. Exposure to severe violence at home remained a strong risk factor for internalizing symptoms for boys, OR: 3.6 [1.4-9.2]. In the adjusted model, a stronger association was found between bad relationships with peers and poor mental health for boys than for girls; OR: 2.0 [1.6-2.3] and OR: 1.4 [1.3-1.6], respectively. For both sexes, witnessing physical violence against mother at home was associated with mental health problems, but did not remain a risk factor when adjusted for confounders. CONCLUSIONS: Gender differences exist in harmful mental health associations with regard to exposure to violence. For girls, violence outside the home is a stronger risk factor than violence at home, compared with boys.

Identifying victims of violence using register-based data.

AIMS: The aim of this study was twofold. Firstly we identified victims of violence in national registers and discussed strengths and weaknesses of this approach. Secondly we assessed the magnitude of violence and the characteristics of the victims using register-based data. METHODS: We used three nationwide registers to identify victims of violence: The National Patient Register, the Victim Statistics, and the Causes of Death Register. We merged these data and assessed the degree of overlap between data sources. We identified a reference population by selecting all individuals in Denmark over 15 years of age that had not been exposed to violence. For the study population and the reference population, socioeconomic and demographic information were retrieved from Statistics Denmark. We used logistic regression models in a cross-sectional analysis to identify characteristics of victims of violence. RESULTS: In 2006, 22,000 individuals were registered as having been exposed to violence. About 70% of these victims were men. Most victims were identified from emergency room contacts and police records, and few from the Causes of Death Register. There was some overlap between the two large data sources. We found significant differences between victims and non-victims according to socio-economic status, education, marital status, and ethnic origin, and also between victims by source of identification. CONCLUSIONS: We have identified a study population consisting of individual victims of violence that opens for further studies on violence. The use of different data sources is a strength but also a potential weakness to epidemiological, health economic, and other analyses using these data.

Parental violence and adolescent mental health.

Being the target of parental violent acts decreases child adjustment and increases the likelihood of mental health problems in childhood and adolescence. Our study analyses how different types of parental violence ranging from verbal threats and swearing to hitting and kicking a child, are associated with child adjustment, indicated by strengths and difficulties scale (SDQ) total problem score, internalizing and externalizing problems as well as prosocial behaviour. We also study whether girls and boys and youths in two Nordic countries respond differently to parental violence. The data consists of a large-scale community sample of 15-16-year old Finnish (n = 5,762) and Danish (n = 3,943) adolescents. The representative data of continental Finland and its Finnish and Swedish speaking ninth graders as well as representative data of Danish ninth grade pupils were collected by the Police College of Finland and in Denmark by the National Institute of Public Health, University of Southern Denmark. The results show a clear dose-response effect between parental violent behaviour and the adolescent's problems. The more severe forms of parental violence were associated with higher levels of SDQ total difficulties and internalizing and externalizing symptoms. There was also a connection between parental violence and the deterioration of prosocial behaviour. The association was gender and nationality specific. The findings imply a high prevalence of parental violence and adverse mental health among the affected Finnish and Danish adolescents. Though the laws have been set in motion to prevent the use of parental physical violence the challenges remain in several domains of child protection, general health care, prevention and intervention.

Cardiovascular disease and long-term occupational exposure to ultrafine particles: A cohort study of airport workers.

AIM: To investigate if ischemic heart disease (IHD) and cerebrovascular disease is associated with long-term occupational exposure to ultrafine particles (UFP) outdoors at an airport. METHODS AND RESULTS: This is a register-based follow-up study based on a cohort comprising an exposed group of 6515 men employed in unskilled work at Copenhagen Airport and a reference group of 61,617 men in unskilled work in other firms in greater Copenhagen during 1990-2012. The exposure was assessed from information on proportion of time spent on the airport apron for each calendar year (apron-years) and the primary exposure measure was cumulated apron-years. The cohort was merged to the National Patient Register that includes data on all contacts to public and private hospitals in Denmark and the Register of Causes of Death. Risk estimates were provided by Poisson regression and adjusted for age, calendar year and educational level. We found no associations between cumulative apron-years and IHD (IRR, 1.00; 95%CI, 0.97-1.03) or cerebrovascular disease (IRR, 1.00; 0.98-1.02) when adjusted for confounders. CONCLUSION: In this large cohort study, we found no association between outdoor occupational exposure to UFP and IHD and cerebrovascular disease.

Is sexual victimization gender specific?: the prevalence of forced sexual activity among men and women in denmark, and self-reported well-being among survivors.

The present study investigates the prevalence of sexual victimization and correlations between sexual victimization and indicators of poor health in two representative samples of men and women in Denmark. Specifically, the authors explore the prevalence of self-reported victimization among adolescents (N = 5,829) and adults (N = 3,932) and analyze differences in self-reported health outcomes between male and female victims and corresponding controls. Gender differences are found in the reported prevalence of sexual victimization. Significantly more females than males reported forced sexual experiences in both samples. Associations between sexual victimization and poor health outcomes are found for both genders. Comparable patterns of association for men and women are found on a number of variables, particularly those pertaining to risk behavior.

Restrictions in means for suicide: an effective tool in preventing suicide: the Danish experience.

Restriction of means for suicide is an important part of suicide preventive strategies in different countries. The effect on method-specific suicide rate and overall suicide rate of restrictions on availability of carbon monoxide, barbiturates, and dextropropoxyphene was examined. From 1970 to 2000, overall suicide mortality and method-specific suicide mortality in Denmark were compared with official information about availability of barbiturates and analgesics and carbon monoxide in vehicle exhaust and household gas. Restrictions on availability of household gas with carbon monoxide content and barbiturates was associated with a decline in the number of suicides and suicides by self-poisoning with these compounds after controlling for the effect of calender year. Restricted access occurred concomittantly with a 55 percent decrease in suicide rate.

Consequences of collective violence with particular focus on the gender perspective--secondary publication.

There is increasing focus on the gender perspective related to the consequences of collective violence. Women run a greater risk of being victims of sexual violence, but few studies have focused on gender differences with respect to physical violence, sexual violations and the impact on health. Further research is needed on these issues as well as on the identification of evidence based interventions.

Differing Procedures for Recording Mortality Statistics in Scandinavia.

BACKGROUND: There may be various reasons for differences in suicide rates between countries and over time within a country. One reason can be different registration practices. AIMS: The purpose of this study was to describe and compare the present procedures for mortality and suicide registration in the three Scandinavian countries and to illustrate potential sources of error in the registration of suicide. METHOD: Information about registration practices and classification procedures was obtained from the cause of death registers in Norway, Sweden, and Denmark. In addition, we received information from experts in the field in each country. RESULTS: Sweden uses event of undetermined intent more frequently than Denmark does, and Denmark more frequently than Norway. There seems to be somewhat more uncertainty among deaths classified as ill-defined and unknown cause of mortality in Norway, compared with the other two countries. Sweden performs more forensic autopsies than Norway, and Norway more than Denmark. In Denmark, in cases of a suspected unnatural manner of death, a thorough external examination of the deceased is performed. CONCLUSION: Differences in the classification of causes of death and in postmortem examinations exist in Scandinavian countries. These differences might influence the suicide statistics in Scandinavia.

A Cohort Study on Meniscal Lesions among Airport Baggage Handlers.

Meniscal lesions are common and may contribute to the development of knee arthrosis. A few case-control and cross-sectional studies have identified knee-straining work as risk factors for meniscal lesions, but exposure-response relations and the role of specific exposures are uncertain, and previous results may be sensitive to reporting and selection bias. We examined the relation between meniscal lesions and cumulative exposure to heavy lifting in a prospective register-based study with complete follow-up and independent information on exposure and outcome. We established a cohort of unskilled men employed at Copenhagen Airport or in other companies in the metropolitan Copenhagen area from 1990 to 2012 (the Copenhagen Airport Cohort). The cohort at risk included 3,307 airport baggage handlers with heavy lifting and kneeling or squatting work tasks and 63,934 referents with a similar socioeconomic background and less knee-straining work. Baggage handlers lifted suitcases with an average weight of approximately 15 kg, in total approximately five tonnes during a 9-hour workday. The cohort was followed in the National Patient Register and Civil Registration System. The outcome was a first time hospital diagnosis or surgery of a meniscal lesion. Baggage handlers had a higher incidence of meniscal lesions than the referents. Within baggage handlers spline regression showed that the incidence rate ratio was 1.91 (95% confidence interval: 1.29-2.84) after five years as a baggage handler and then decreased slowly to reach unity after approximately 30 years, adjusted for effects of potential confounders. This relation between baggage handling and meniscal lesions was present for work on the apron which involves lifting in a kneeling or squatting position, but not in the baggage hall, which only involves lifting in standing positions. The results support that long-term heavy lifting in a kneeling or squatting position is a risk factor for the development of symptomatic meniscal lesions.