The effect of gestational age on major neurodevelopmental disorders in preterm infants

BACKGROUND

Preterm infants have an increased risk of neurodevelopmental disorders. We established a direct quantitative comparison of the association between the degree of prematurity and three different neurodevelopmental disorders.

METHODS

In this cohort study, we combined data from 995,498 children in the Danish Medical Birth Register, from birth years 1997-2013, with information on cerebral palsy, epilepsy, and special educational needs. We estimated the gestational week-specific prevalence and risk for each of the disorders.

RESULTS

The risk ratio of cerebral palsy at gestational weeks 21-24, compared to term birth, was more than ten times higher than for the two other disorders. The prevalence of epilepsy and special educational needs declined almost parallel, with 9.2% (4.6%-13.5%) and 12.5% (11.2%-13.7%), respectively, per week of gestation toward term birth. Cerebral palsy did not decline similarly: from gestational weeks 21-24 until week 29 the prevalence declined insignificantly by 0.6% (-11.1%-11.0%) per week; whereas from week 29 until term, the prevalence declined markedly by 36.7% (25.9%-45.9%) per week.

CONCLUSIONS

The prevalence and risk of cerebral palsy are affected differently by the degree of prematurity compared with epilepsy and special educational needs, possibly reflecting important differences in cerebral pathophysiology.

IMPACT

For each week of gestation toward term birth, there was a clear log-linear decline in the prevalence of early childhood epilepsy and special educational needs. In contrast, the risk of cerebral palsy was high at the earliest gestational age, and the prevalence did not decline significantly until gestational week 29, from where it declined notably by nearly 40% for each week of gestation until term birth. Our results indicate important differences in the pathophysiological processes that associate preterm birth with these three neurodevelopmental disorders.

Declining prevalence of cerebral palsy in children born at term in Denmark

AIM

To investigate reasons for the declining prevalence of cerebral palsy (CP) in children born at term in Denmark by evaluating obstetric and neonatal factors associated with CP, and their changes over time.

METHOD

In this cohort study, we included 987 495 children (504 600 [51.1%] males and 482 895 [48.9%] females) born after 37 completed gestational weeks during birth years 1997 to 2013. Risk ratios of CP for each factor were calculated with log-binominal regression analyses. Significant factors were evaluated concerning their development in prevalence over time.

RESULTS

In the antenatal period, there were significant associations with an increased risk of CP and high maternal body mass index (BMI), smoking during pregnancy, nulliparity, male sex, gestational age, and low birthweight. In the study period, fewer females smoked during pregnancy and fewer children were born post-term, dropping from 22.6% to 11.4% and 9.4% to 2.5% respectively. Conversely, the proportion of females with high BMI increased. Most significant risk factors were found in the neonatal period, with an increase in children with diagnosed birth defects and children admitted to neonatal care.

INTERPRETATION

Reasons for the declining prevalence of CP appear to be multifactorial and likely include the decline in maternal smoking and children born post-term along with centralization and advances in neonatal treatment.

Effects of individual and parental educational levels on multimorbidity classes: a register-based longitudinal study in a Danish population

OBJECTIVES

To assess the effects of individual educational level in adulthood and parental educational level during childhood, as well as combinations of individual and parental educational levels, on multimorbidity classes.

DESIGN AND SETTING

In this longitudinal study, we used data from a random sample of the Danish population aged 32-56 years without multimorbidity in 2010 (n=102 818). The study population was followed until 2018. Information on individual and parental educational levels and chronic conditions was obtained from national registers. Multinomial logistic regression analyses were adjusted for sex, age and ethnicity.

OUTCOME MEASURE

Seven multimorbidity classes were identified using latent class analysis based on 47 chronic conditions. Persons deceased during follow-up comprised a separate class.

RESULTS

We found an independent effect of individual educational level on five multimorbidity groups and death, most pronounced for the multimorbidity group 'Many conditions' (OR=1.89, 95% CI 1.58 to 2.26 for medium and OR=3.22, 95% CI 2.68 to 3.87 for short compared with long educational level) and of parental education on four groups and death, most pronounced for the multimorbidity group 'Many conditions' (OR=1.36, 95% CI 1.07 to 1.73 for medium and OR=1.48, 95% CI 1.15 to 1.89 for short compared with long educational level). Odds of belonging to four multimorbidity classes increased with lower combination of individual and parental educational levels, most pronounced for the multimorbidity group 'Many conditions'.

CONCLUSION

As both individual and parental educational levels contribute to the risk of multimorbidity, it is important to address inequality throughout the life course to mitigate multimorbidity. Future studies could adopt a life course approach to investigate the mediating role of behavioural, clinical, environmental and other social factors.

Using both electromyography and movement disorder assessment improved the classification of children with dyskinetic cerebral palsy

AIM

Children with dyskinetic cerebral palsy (CP) are often severely affected and effective treatment is difficult, due to different underlying disease mechanisms. Comprehensive systematic movement disorder evaluations were carried out on patients with this disorder.

METHODS

Patients born from 1995 to 2007 were identified from the Danish Cerebral Palsy Register and referrals to the neuropaediatric centre, Rigshospitalet, Copenhagen. They were classified by gross motor function, manual functional ability, communication ability, dystonia and spasticity. Electromyography was carried out on the upper and lower limbs. Magnetic resonance imaging scans were revised, and aetiological searches for underlying genetic disorders were performed.

RESULTS

We investigated 25 patients with dyskinetic CP at a mean age of 11.7 years. Dystonia, spasticity and rigidity were found in the upper limbs of 21, four and six children, respectively, and in the lower limbs of 18, 18 and three children. The mean total Burke-Fahn-Marsden score for dystonia was 45.02, and the mean Disability Impairment Scale level was 38% for dystonia and 13% for choreoathetosis. Sustained electromyography activity was observed in 20/25 children. Stretching increased electromyography activity more in children with spasticity. There were 10 re-classifications.

CONCLUSION

The children had heterogenic characteristics, and 40% were reclassified after systematic movement disorder evaluation.

Disparities in postpartum depression screening participation between immigrant and Danish-born women

BACKGROUND

Qualitative studies suggest that immigrant women experience barriers for postpartum depression (PPD) screening. This study examines the prevalence of participation in PPD screening in the universal home-visiting programme in Denmark, in relation to migrant status and its association with acculturation factors, such as length of residence and age at migration.

METHODS

The sample consists of 77 694 births from 72 292 mothers (2015-18) that participated in the programme and were registered in the National Child Health Database. Lack of PPD screening using the Edinburgh Postpartum Depression Scale (EPDS) was examined in relation to migrant group and acculturation factors. We used Poisson regression with cluster robust standard errors to estimate crude and adjusted relative risk.

RESULTS

In total, 27.8% of Danish-born women and 54.7% of immigrant women lacked screening. Compared with Danish-born women, immigrant women in all groups were more likely to lack PPD screening (aRR ranging from 1.81 to 1.90). Women with low acculturation were more likely to lack screening. Women who migrated as adults [aRR = 1.27 (95% CI 1.16, 1.38)] and women who had resided in Demark for <5 years [aRR = 1.37 (95% CI 1.28, 1.46)] were more likely to lack screening.

CONCLUSIONS

Immigrant women in Denmark, particularly recent immigrants, are at increased risk of not being screened for PPD using the EPDS. This can lead to under-recognition of PPD among immigrant women. More work is needed to understand how health visitors recognize the mental health needs of immigrant women who are not screened, and whether this gap results in reduced use of mental health services.

Parental education, parent-child relations and diagnosed mental disorders in childhood: prospective child cohort study

BACKGROUND

Mental disorder in childhood is an important public health issue. We aimed to examine the prospective association between parental education at childbirth and diagnosed mental disorders in young children and explore whether this association was mediated or modified by parent-child relations in infancy.

METHODS

Prospective cohort study of all newborn was from 2002 to 2010 from 16 municipalities in the capital region of Copenhagen, Denmark, with follow-up until their 8th birthday, N = 40 762. Baseline data included information from national population registers and from health visitors' records at child aged 0 to 10 months. Outcome variable: any mental disorder diagnosed at hospital from age 11 months to 8 years.

RESULTS

Low parental education was predictive of diagnosed child mental disorder, adjusted odds ratio (AOR) = 1.83 (95% CI 1.49-2.23). Problematic parent-child relation at age 8-10 months was also predictive of mental disorder, AOR = 2.06 (1.57-2.70) but did not mediate the association between parental education and mental disorder. AOR for mental disorders was 3.24 (2.03-5.16 for the combination vocational training and problematic parent-child relation and 2.49 (1.42-4.38) for the combination primary school and problematic parent-child relation.

CONCLUSIONS

Low parental education and problematic parent-child relation were independent risk factors for diagnosed mental disorders in the age span of 11 months to 8 years.

The Danish Multiple Sclerosis Registry

OBJECTIVES

The Danish Multiple Sclerosis Registry is the oldest operative and nationwide MS registry. We present The Danish Multiple Sclerosis Registry with its history, data collection, scientific contribution, and national and international research collaboration.

MATERIALS AND METHODS

Detailed description of data collection, completeness, quality optimizing procedures, funding, and legal, ethical and data protection issues are provided.

RESULTS

The total number of registered cases with clinical isolated syndrome and multiple sclerosis since 1956 was by start of May 2020 30,023 of whom 16,515 cases were alive and residing in Denmark, giving a prevalence rate of about 284 per 100,000 population. The mean annual number of new cases receiving an MS diagnosis was 649 per year in the period 2010 to 2019. In total, 7,945 patients (48.1%) are receiving disease modifying therapy at the start of May 2020.

CONCLUSIONS

Multiple Sclerosis registers are becoming increasingly important, not only for epidemiological research but also by quantifying the burden of the disease for the patients and society and helping health care providers and regulators in their decisions. The Danish Multiple Sclerosis Registry has served as data source for a number of scientific publications including epidemiological studies on changes in incidence and mortality, cohort studies investigating risk factors for developing MS, comorbidities and socioeconomic outcomes in the MS population, and observational studies on effectiveness of disease modifying treatments outside the narrow realms of randomized clinical trials.

Continuing decline in the prevalence of cerebral palsy in Denmark for birth years 2008-2013

AIM

To quantify and analyse the prevalence and clinical features of cerebral palsy (CP) in Denmark for birth years 2008-2013 and compare results with previous periods.

METHOD

A nationwide register-based study covering all children with a confirmed diagnosis of CP born in Denmark. Information about CP subtype, aetiology and severity was collected from the Cerebral Palsy Follow-up Program and supplemented from medical files. Data from the Danish Medical Birth Register was included, and the results were compared to previous data from the Danish National Cerebral Palsy Register. Prevalence per 1000 live births and proportions were analysed using the Cochran-Armitage test for trend.

RESULTS

The period covered 368,618 live births and 636 children with CP, making the overall prevalence for the period 1.73 per 1000 live births. This was significantly lower than the prevalence of 1.99 for the previous period 1999-2007 (p = 0.004). The decline in prevalence between the two periods was mainly due to a decrease in children with bilateral spastic and dyskinetic CP born after 37 gestational weeks. The decline in prevalence was accompanied by a smaller proportion of children with associated impairment.

CONCLUSION

We found a decrease in prevalence and severity in CP among Danish children. The decline was most pronounced in children born after 37 gestational weeks with severe subtypes of CP. National guidelines that recommend induction of labour before the completion of week 42 and therapeutic hypothermia for term neonates with hypoxic-ischaemic encephalopathy, may have contributed to the decline.

Patterns of multimorbidity and demographic profile of latent classes in a Danish population-A register-based study

Background

Multimorbidity is an increasing public health concern and is associated with a range of further adverse outcomes. Identification of disease patterns as well as characteristics of populations affected by multimorbidity is important for prevention strategies to identify those at risk.

Aim

The aim of the study was to identify and describe demographic characteristics of multimorbidity classes in three age groups (16–44 years, 45–64 years, and 65+ years).

Methods

Based on register information on 47 chronic diseases and conditions, we used latent class analysis to identify multimorbidity classes in a random sample of the Danish population (n = 470,794). Information on sociodemographic characteristics (age, sex, region of origin, educational level, employment status, and marital status) was obtained from registers and linked to the study population. Age- and sex-adjusted multinomial logistic regression models were used to examine associations between multimorbidity classes and sociodemographic characteristics.

Results

We identified seven classes among individuals in the age groups 45–64 years and 65+ years and five classes in the age group 16–44 years. Overall, the classes were similar in the three age groups, but varied in size, i.e. the class ‘No or few diseases’ was larger in the younger age group. The class ‘Many diseases’ (a class with both somatic diseases and mental illnesses) was only seen in individuals aged 45–64 years and 65+ years. There were social inequalities in odds of belonging to the multimorbidity classes compared to the healthier class. These social inequalities varied but were especially strong in the classes named ‘Many diseases’ and ‘Mental illness, epilepsy’.

Conclusion

The results of the study suggest that there are social inequalities in multimorbidity but that these inequalities are not universal to all types of multimorbidity. This supports that multimorbidity is diverse and should be prevented and treated accordingly.

Study protocol of the Healthy High School study: a school-based intervention to improve well-being among high school students in Denmark

BACKGROUND

The prevalence of low well-being, perceived stress and unhealthy behaviours is high among high school students, but few interventions have addressed these problems. The aim of this paper is to present a study protocol of a cluster randomised controlled trial evaluating the Healthy High School (HHS) intervention programme. The intervention programme is designed to improve well-being (primary outcome) by preventing 1) stress and promoting 2) sleep, 3) sense of community, 4) physical activity (PA) and 5) regular and healthy meals among high school students in Denmark.

METHODS

The development of the HHS study was guided by the Intervention Mapping protocol. The intervention comprises four components: 1) a teaching material, 2) a smartphone app, 3) a catalogue focusing on environmental changes, and 4) a peer-led innovation workshop aiming at inspiring students to initiate and participate in various movement activities. The HHS study employs a cluster-randomised controlled trial design. Thirty-one high schools across Denmark were randomly allocated to intervention (16 schools) or control (15 schools) groups. The study included all first-year students (~ 16 years of age) (n = 5976 students). Timeline: Intervention: August 2016 - June 2017. Collection of questionnaire data: Baseline (August 2016), 1st follow-up (May 2017) and 2nd follow-up (April 2018). All students were invited to participate in a monthly sub-study about perceived stress using text messages for data collection (September 2016 - June 2017). PA was objectively assessed among a sub-sample of students using accelerometers (Axivity, AX3) in August 2016 and May 2017.

PRIMARY OUTCOME MEASURES

Student well-being measured by the Cantril Ladder and the five item World Health Organisation Well-being Index (individual level outcomes).

SECONDARY OUTCOME MEASURES

Stress (10-item Perceived Stress Scale), sleep (quantity and quality), PA (hours of moderate-to-vigorous PA per week, hours of daily sedentary time and average daily PA), meal habits (daily intake of breakfast, lunch, snacks and water), and strong sense of community in class and at school, respectively (individual level outcomes). The study encompasses process and effect evaluation as well as health economic analyses.

TRIAL REGISTRATION

ISRCTN ISRCTN43284296, 28 April 2017, retrospectively registered.

Children with dyskinetic cerebral palsy are severely affected as compared to bilateral spastic cerebral palsy

AIM

We aimed at describing clinical findings in children with dyskinetic as compared to bilateral spastic cerebral palsy (CP).

METHODS

Data were extracted from the Danish nationwide CP register. Participants were born in 1999-2007 and were 5-6 years at ascertainment.

RESULTS

The total number of CP cases was 1165 of which 92 had dyskinetic and 540 bilateral spastic CP. Prevalence of dyskinetic CP was 0.16 per 1000 live births. In participants with dyskinetic compared to bilateral spastic CP, there was more frequently an Apgar level less than five at five minutes (22.7% vs. 11.2%) and neonatal seizures (43.5% vs. 28.5%), but less respiratory deficiency, hyperbilirubinaemia and sepsis. Impairment based on gross motor function classification was more severe in dyskinetic CP (level III-V 90.0% vs. 66.0%). In dyskinetic CP, there was a high rate of reduced developmental quotient (68.1%), visual impairment (39.3%) and epilepsy (51.6%). Basal ganglia lesions were more prevalent in dyskinetic compared to bilateral spastic CP (27.7% vs. 12.8%).

CONCLUSION

Cases of dyskinetic CP had overlapping clinical features with cases of bilateral spastic CP, but differed significantly in several perinatal risk factors. The children with dyskinetic CP had experienced more peri- or neonatal adverse events, and neurodevelopmental impairment was severe.

Reproductive history of the Danish multiple sclerosis population: A register-based study

Background:

A diagnosis of multiple sclerosis (MS) may impact the choice of parenthood.

Objective:

To investigate the number of live births, abortions and ectopic pregnancies among persons with MS.

Methods:

From the Danish Multiple Sclerosis Registry, we extracted data from all persons diagnosed with MS from 1960 to 1996 and matched each MS person with four reference persons. We used a negative binomial regression model for the live births and Poisson regression model for abortions and ectopic pregnancies. The total fertility rate (TFR) during 1960–2016 and the annual number of live births in the MS population were analysed.

Results:

Persons with MS had fewer children than reference persons. Fewer women with MS had elective abortions after diagnosis (incidence rate ratio (IRR) = 0.88; 95% confidence interval (CI) = 0.78–1.00) than reference persons. There was no difference regarding the number of elective abortions, spontaneous abortions or ectopic pregnancies after onset. The TFR was lower for women with MS than for reference persons, and the number of annual live births by MS persons increased during 1960–2016.

Conclusion:

MS seems to considerably impact reproductive choices, especially after clinical diagnosis, resulting in the MS population having fewer children than the general population.

Decline in severe spastic cerebral palsy at term in Denmark 1999-2007

AIM

To analyse trends in prevalence and severity of cerebral palsy (CP) in Denmark in birth years 1999-2007 and compare with previous periods.

METHOD

Data has been collected uniformly in the Danish cerebral palsy national register nationwide since 1995. Rates in the time periods 1999-2001, 2002-2004 and 2005-2007 covering 585,393 births were analysed by gestational age and subtypes.

RESULTS

Total number of CP cases in the period was 1165. The overall prevalence of CP decreased significantly from 2.1 in 1999-2001 to 1.8 in 2005-2007 per 1000 livebirths (p = 0.022). The decline was only significant for children born at term (p = 0.007) but not for the preterm (p = 0.44). The decline in children born at term was based on a decrease in bilateral spastic CP (n = 117 in years 1999-2001 and n = 59 in 2005-2007). Multidisciplinary obstetric skills training with neonatal resuscitation in Denmark was initiated in 2003 and timely associated with the decrease. The prevalence of unilateral spastic CP the prevalence did not change, but in the two last time periods more children had a right-sided than left-sided unilateral spastic CP.

CONCLUSION

The decline in rate of CP seen in 2005-2007 as compared to 1999-2001 was mainly based on fewer cases of severe spastic CP in term infants. We hypothesize that improved neonatal resuscitation in the delivery room may be partly responsible for the decrease. In premature children the decline was not significant in this time period, but has been dramatically decreasing in the years before the time period here analysed.

"To survey or to register" is that the question for estimating population incidence of injuries?

Background

Measuring the true incidence of injury or medically attended injury is challenging. Population surveys, despite problems with recall and selection bias, remain the only source of information for injury incidence calculation in many countries. Emergency department (ED) registry based data provide an alternative source.The aim of this study is to compare the yearly incidence of hospital treated Home and Leisure Injuries (HLI), and Road Traffic Injuries (RTI) estimated by survey-based and register-based methods and combine information from both sources in to a comprehensive injury burden pyramide.

Methods

Data from Luxemburg's European Health Examination Survey (EHES-LUX), European Health Interview Survey (EHIS) and ED surveillance system Injury Data Base (IDB) collected in 2013, were used. EHES-LUX data on 1529 residents 25-64 years old, were collected between February 2013-January 2015. EHIS data on 4004 other residents aged 15+ years old, were collected between February and December 2014. Participants reported last year's injuries at home, leisure and traffic and treatment received. Two-sided exact binomial tests were used to compare incidences from registry with the incidences of each survey by age group and prevention domain. Data from surveys and register were combined to build an RTI and HLI burden pyramide for the 25-64 years old. This project was part of the European Union project BRIDGE-Health (BRidging Information and Data Generation for Evidence-based Health Policy and Research).

Results

Among 25-64 years old the incidence of hospital treated injuries per thousand population was 60.1 (95% CI: 59.2-60.9) according to IDB, 62.1 (95% CI: 50.6-75.4) according to EHES-LUX and 53.2 (95% CI: 45.0-62.4) according to EHIS. The incidence of hospital admissions was 3.7 (95% CI: 3.5-4.0) per thousand population from IDB-Luxembourg, 12.4 (95% CI: 7.5-19.3) from EHES-LUX and 18.0 (95% CI: 13.3-23.8) from EHIS. For 15+ years-old incidence of hospital treated HLI was 62.8 (95% CI: 62.1-63.5) per thousand population according to IDB whereas the corresponding EHIS estimate was lower at 46.9 (95% CI: 40.4-54.0). About half of HLI and RTI of the 25-64 years old were treated in hospital.

Conclusion

The overall incidence estimate of hospital treated injuries from both methods does not differ for the 25-64 years old. Surveys overestimate the number of hospital admissions, probably due to memory bias. For people aged 15+ years, the survey estimate is lower than the register estimate for hospital treated HLI injuries, probably due to selection and recall biases. ED based registry data is to be preferred as single source for estimating the incidence of hospital treated injuries in all age groups.

Mental health among children of mothers with multiple sclerosis: A Danish cohort and register-based study

BACKGROUND

Multiple sclerosis is associated with an increased risk of developing physical, cognitive, and mental health problems. Current studies have demonstrated variating outcomes of parental multiple sclerosis mental health problems and their children's mental health development.

OBJECTIVE

The purpose of this study was to investigate whether maternal multiple sclerosis is associated with the mental health status of their child.

METHODS

Data from the Danish National Birth Cohort (DNBC) were merged with information from the Danish Multiple Sclerosis Registry. Two proxies, total difficulties score and prediction of any psychiatric diagnosis based on the strengths and difficulties questionnaire, were used to measure the mental health status of the children. The two groups were compared using Mann-Whitney and logistic regression analyses.

RESULTS

For the total difficulties score the control and exposed group consisted of respectively n = 42,016 and n = 40, and for the prediction of any psychiatric diagnosis respectively n = 16,829 and n = 17. We found no statistically significant association between maternal multiple sclerosis and mental health status on neither of the proxies.

CONCLUSION

Maternal multiple sclerosis did not show any association with the mental health status of their children at age eleven. On the contrary, other studies conclude that there is an association between maternal multiple sclerosis and the child's mental health status, one especially mediated by the maternal mental health status.

Spontaneous Fibrinolysis Demonstrated by Immunological Technique

The occurrence of spontaneous fibrinolysis has been investigated in various medical diseases, e. g. myocardial infarction, cerebral stroke, phlebothrombosis, pulmonary embolism, metastasing cancer, and others. Serum from patients has been tested for fibrinolytic break-down products by use of immunodiffusion and Immunoelectrophoresis with double-diffusion. It was anticipated that positive results might provide useful diagnostic, prognostic, and therapeutic information, particularly in patients with myocardial infarction. However, there is no apparent correlation between the occurrence of spontaneous fibrinolysis and the course of disease.

In patients with haemorrhagic diathesis the tests give useful information, but in the remaining groups tested, the significance of occurring fibrinolytic break-down products cannot yet be evaluated.

Fibrinogen Break-Down Products and Clotting Parameters

Fibrinogen and fibrin break-down products (b. p.) in vitro and in vivo are identified by immunodiffusion, Immunoelectrophoresis and acryl-disc-electrophoresis with immunodiffusion.

The clotting parameters obtained in vitro by addition of b. p. to plasma system are compared with similar tests in patients with spontaneous occurence of b. p.

B. p. formed after short plasmin digestion of fibrinogen prolong significantly the thrombin time, reduce the maximal thrombin activity in the thrombin generation test and inhibit the clot formation in TEG, increasing the k- and reducing the mA values. These b. p. are further digested. The plasmin resistant fractions exhibiting D or E antigenic properties are less active. The specific activity of the different fractions were not investigated.

The clotting parameters in patients with spontaneous occurence of b. p. (D fraction) are very different. Defects similar, but not identical, to those obtained in vitro by addition of b. p. to plasma systems are seen. Accelerated thrombin generation, enhanced fibrin polymerization and accelerated clot formation in TEG are found in others. Similar differences in fibrinolytic activity are demonstrated. The presence of b. p. might be the only abnormality found. B. p. are suggested to develop either as the result of localized thrombo-fibrinolysis or during a more generalized increase in fibrinolytic activity.

Immunological methods can demonstrate b. p. in the concentration of 0.05 to 0.10 mg%. The thrombin time is not significantly prolonged until b. p. are present in the concentration of 0.5 mg% (early b. p.) - 2 mg% (later b. p.) as estimated spectrophotometrically.

Incidence of MS has increased markedly over six decades in Denmark particularly with late onset and in women

OBJECTIVE

To describe the pattern of development of incidence of multiple sclerosis (MS) over 60 years in Denmark with age-period-cohort analyses and seasonality of birth.

METHODS

Data on virtually all patients with onset of MS have since 1950 been prospectively recorded and kept in the Danish Multiple Sclerosis Registry with multiple sources of notification. Annualized incidence rates per 100,000 were directly standardized to the European Standard Population.

RESULTS

We have registered 19,536 cases with clinical onset of confirmed MS in Denmark from 1950 to 2009. From the 1950-1959 to the 2000-2009 onset period, incidence more than doubled in women, with an increase from 5.91 (95% confidence interval [CI]: 5.60-6.24) to 12.33 (95% CI: 11.91-12.75) per 100,000 per year compared with a modest 24% increase in men from 4.52 (95% CI: 4.24-4.81) to 6.08 (95% CI: 5.79-6.38). With age at onset of 50 years and older, incidence increased with a factor 4.30 in women and 2.72 in men. The female/male sex ratio increased over time and with year of birth. Age-period-cohort analysis revealed a significant birth cohort effect in addition to the age and period effect. We found no statistically significant seasonality of births.

CONCLUSION

The incidence of MS has doubled in women, most pronounced with late onset, and has only modestly increased in men. Lifestyle changes in the female population that could include fewer childbirths, increased occurrence of obesity, and increased cigarette consumption may have a role.

Comorbidity in multiple sclerosis is associated with diagnostic delays and increased mortality

OBJECTIVE

To investigate the effect of chronic comorbidity on the time of diagnosis of multiple sclerosis (MS) and on mortality in MS.

METHODS

We conducted a population-based, nationwide cohort study including all incident MS cases in Denmark with first MS symptom between 1980 and 2005. To investigate the time of diagnosis, we compared individuals with and without chronic comorbidity using multinomial logistic regression. To investigate mortality, we used Cox regression with time-dependent covariates, following study participants from clinical MS onset until endpoint (death) or to the end of the study, censuring at emigration.

RESULTS

We identified 8,947 individuals with clinical onset of MS between 1980 and 2005. In the study of time of diagnosis, we found statistically significant odds ratios for longer diagnostic delays with cerebrovascular comorbidity (2.01 [1.44-2.80]; <0.0005), cardiovascular comorbidity (4.04 [2.78-5.87]; <0.0005), lung comorbidity (1.93 [1.42-2.62]; <0.0005), diabetes comorbidity (1.78 [1.04-3.06]; 0.035), and cancer comorbidity (2.10 [1.20-3.67]; 0.009). In the mortality study, we found higher hazard ratios with psychiatric comorbidity (2.42 [1.67-3.01]; <0.0005), cerebrovascular comorbidity (2.47 [2.05-2.79]; <0.0005), cardiovascular comorbidity (1.68 [1.39-2.03]; <0.0005), lung comorbidity (1.23 [1.01-1.50]; 0.036), diabetes comorbidity (1.39 [1.05-1.85]; 0.021), cancer comorbidity (3.51 [2.94-4.19]; <0.0005), and Parkinson disease comorbidity (2.85 [1.34-6.06]; 0.007).

CONCLUSIONS

An increased awareness of both the necessity of neurologic evaluation of new neurologic symptoms in persons with preexisting chronic disease and of optimum treatment of comorbidity in MS is critical.

Excess mortality among patients with multiple sclerosis in Denmark has dropped significantly over the past six decades: a population based study

BACKGROUND

Lifetime expectancy in multiple sclerosis (MS) is reduced. Few studies have had sufficient follow-up or sufficient number of patients to assess if survival has improved with time. However, a recent meta-analysis found no time-dependent change in MS excess mortality across studies over recent decades.

OBJECTIVE

To investigate whether short-term all-cause excess mortality in patients with MS in the total Danish population has changed over the last six decades.

PATIENTS AND METHODS

We included all patients with MS recorded in the nationwide Danish MS Registry with definite or probable MS and onset from 1950 through 1999. The Danish Civil Registration System provided date of death for all deceased patients with follow-up in 2015, and Statistics Denmark supplied specific population mortality. We calculated excess number of death per 1000 person-years (EDR) and standardised mortality ratio (SMR).

RESULTS

We included 18 847 patients among whom 6102 had died as opposed to 2492 expected deaths. EDR was 10.63 (95% CI 10.19 to 11.09) and a SMR was 2.45 (95% CI 2.39 to 2.51). The 15-year EDR dropped gradually from 11.29 (95% CI 9.95 to 12.73) in the 1950-1959 onset cohort to 2.56 (95% CI 1.98 to 3.18) in the 1990-1999 onset cohort, and SMR dropped from 4.48 (95% CI 4.06 to 4.92) to 1.80 (95% CI 1.62 to 1.99).

CONCLUSION

The decline in short-term excess mortality in MS started decades before disease-modifying treatment of MS became available, before use of MRI became widespread, and before the McDonald diagnostic criteria were introduced. A change in the MS cohorts with fewer malignant cases may be a significant contributor.

Shoulder Muscle Load during Pushing and Pulling

Substituting lifting with pushing and pulling generally reduces the disc compression in the low back. However, from a biomechanical point of view, pushing and pulling tasks are much more complex to analyse compared to lifting. Instead of being close to vertical, the force directions are virtually unknown, and may vary during different phases of the task. The relation between external force and internal load is not simple, as force direction and body posture may change accordingly. Further, focus has mainly been on the lumbar spine and not on shoulder load. Although the lumbar spine load is reduced, shoulder muscle load is not necessarily changed to the same extent during pushing and pulling compared to lifting. Therefore, shoulder load is brought into focus in a study of pushing and pulling. Seven male waste collectors pushed and pulled two-wheeled containers with up to 50 kg of waste. When performing one-handed pull behind the body, the force was up to 280 N, and the internal shoulder flexion moments were up to 80 Nm in the initial phase, close to the subject's maximum shoulder flexion moments. For the two-handed push in front of the body, the total force was up to 360 N, corresponding to approximately 180 N for each hand. Pushing caused lower shoulder moments, up to 34 Nm in the initial phase. During steady state, the total force was up to 230 N when pushing and 130 N when pulling. Shoulder moments were below 27 Nm when pulling and below 16 Nm when pushing (all results are given as mean of subjects). Regarding the relation between exposure and internal load, there was a positive relation between the magnitude of the hand force and the shoulder moment (r=0.48). For the compression in the lumbar spine there was no relation to the magnitude of the hand force (r=0.05).

In conclusion, although loads on the low back during pushing and pulling are relatively small, loads on the shoulder muscles may be very high in some cases. Pushing and pulling may therefore be a risk factor for shoulder disorders.

Inverse comorbidity in multiple sclerosis: Findings in a complete nationwide cohort

BACKGROUND

Inverse comorbidity is disease occurring at lower rates than expected among persons with a given index disease. The objective was to identify inverse comorbidity in MS.

METHODS

We performed a combined case-control and cohort study in a total nationwide cohort of cases with clinical onset of MS 1980-2005. We randomly matched each MS-case with five population controls. Comorbidity data were obtained from multiple, independent nationwide registries. Cases and controls were followed from January 1977 to the index date, and from the index date through December 2012. We controlled for false discovery rate and investigated each of eight pre-specified comorbidity categories: psychiatric, cerebrovascular, cardiovascular, lung, and autoimmune comorbidities, diabetes, cancer, and Parkinson's disease.

RESULTS

A total of 8947 MS-cases and 44,735 controls were eligible for inclusion. We found no inverse associations with MS before the index date. After the index date, we found a decreased occurrence of chronic lung disease (asthma and chronic obstructive pulmonary disease) (HR 0.80 (95% CI 0.75-0.86, p<0.00025)) and overall cancer (HR 0.88 (95% CI 0.81-0.95, p=0.0005)) among MS-cases.

CONCLUSION

This study showed a decreased risk of cancers and pulmonary diseases after onset of MS. Identification of inverse comorbidity and of its underlying mechanisms may provide important new entry points into the understanding of MS.

Employment, disability pension and income for children with parental multiple sclerosis

Background:

Little is known about the consequences of parental multiple sclerosis (MS) on offspring’s socioeconomic circumstances.

Objective:

To investigate employment, disability pension and income in offspring of parents with MS compared with matched reference persons in a nationwide register-based cohort study.

Methods:

All Danish-born persons with onset of MS during 1950–1986 were retrieved from the Danish Multiple Sclerosis Registry. Their offspring were identified using the Civil Registration System. One random offspring from each sibship was matched by sex and year of birth with eight random reference persons.

Results:

We included 2456 MS offspring and 19,648 reference persons. At age 30, employment was lower among MS offspring than reference children (odds ratio (OR): 0.89; 95% confidence interval (CI): 0.84–0.95; p = 0.0003), and they more often received disability pension (OR: 1.31; 95% CI: 1.15–1.50; p < 0.0001) at ages 30 and 40 but not at age 50. Although the mean income was not significantly lower for the MS offspring cohort, most of them attained an annual personal income below 250,000 DKK (Danish krone), that is, ~33,650 EUR (OR: 0.91; 95% CI: 0.84–0.99; p = 0.04).

Conclusion:

Having had a parent with MS may affect employment and increase the risk of disability pension and low income in adult life.

Educational achievements of children of parents with multiple sclerosis: A nationwide register-based cohort study

Little is known about the impact of parental multiple sclerosis (MS) on offspring's educational attainment. The objective of the study was to examine educational achievements in offspring of parents with MS compared with matched children of parents without MS in a nationwide register-based cohort study. Children of all Danish-born residents with onset between 1950 and 1986 were identified by linking the Danish Multiple Sclerosis Registry with the Civil Registration System. Twins, children with MS, and emigrated persons were excluded. The reference cohort consisted of randomly drawn individuals from the Civil Registration System without parental MS matched 8:1 to the MS offspring by sex and year of birth. Information about education was linked to the cohorts from nationwide educational registries. We included 4177 children of MS parents and 33,416 reference persons. Children of MS parents achieved statistically significant higher average grades than the reference cohort in their final exam of basic school with a mean grade difference of 0.46 (95 % CI 0.22-0.69; p = 0.0002). We found no difference in achievement of educational level above basic school (OR 1.04; 95 % CI 0.98-1.10; p = 0.20). There was a trend toward more MS offspring attaining health-related educations (OR 1.10; 95 % CI 1.00-1.21; p = 0.06). In conclusion, children of MS parents showed a small advantage in grade point average in final examinations in basic school, and they more often tended toward health-related educations. This study revealed no negative consequences of parental MS on grades and highest educational level achieved.

High-dose erythropoietin in patients with progressive multiple sclerosis: A randomized, placebo-controlled, phase 2 trial

Background:

Erythropoietin (EPO) is a part of an endogenous neuroprotective system in the brain and may address pathophysiological mechanisms in progressive multiple sclerosis (MS).

Objective:

To evaluate a treatment effect of EPO on progressive MS.

Methods:

This was a single-center, randomized, double-blind, placebo-controlled phase 2 trial, in which 52 patients with secondary or primary progressive MS were allocated to treatment with recombinant EPO (48,000 IU) or placebo, administered intravenously 17 times during 24 weeks. Patients had an Expanded Disability Status Score (EDSS) from 4 to 6.5 and clinical progression without relapses in the 2 preceding years. The primary outcome was the change in a composite measure of maximum gait distance, hand dexterity, and cognition from baseline to 24 weeks.

Results:

A total of 50 patients completed the study. Venesection was performed often but no thromboembolic events occurred. We found no difference in the primary outcome between the EPO and the placebo group using the intention-to-treat principle ( p = 0.22). None of the secondary outcomes, neither clinical nor magnetic resonance imaging (MRI) measures showed any significant differences.

Conclusion:

This study provides class II evidence that treatment with high-dose EPO is not an effective treatment in patients with moderately advanced progressive MS.

Shift work at young age is associated with increased risk of multiple sclerosis in a Danish population

BACKGROUND

Epidemiological studies suggest an important role for environmental factors in developing multiple sclerosis (MS). Furthermore several studies have indicated that the effect of environmental factors may be especially pronounced in adolescents. Recently only one study investigated and found that shift work at young age is associated with an increased risk of developing MS. In this study we focused on the effect of shift work in the vulnerable period between 15-19 years.

OBJECTIVE

The aim of this study was to investigate the association between shift work at young age and the risk of developing MS.

METHODS

We performed a large case-control study including 1723 patients diagnosed with MS and 4067 controls. MS patients were recruited from the Danish Multiple Sclerosis Biobank and controls from The Danish Blood Donor Study. Information on working patterns and lifestyle factors was obtained using a comprehensive lifestyle-environmental factor questionnaire with participants enrolled between 2009 and 2014. Logistic regression models were used to investigate the association between shift work at age 15-19 years and the subsequent risk of MS and were controlled for effects due to established MS risk factors.

RESULTS

We found a statistically significant association when total numbers of night shifts were compared with non-shift workers. For every additional 100 night shifts the odds ratio (OR) for MS was 1.20 (95% confidence interval (CI), 1.08-1.34, p=0.001). Increasing intensity of shift work also increased MS risk. For every additional night per month the OR was 1.04 (95% CI, 1.01-1.06, p=0.002). Duration of shift work in years was not associated with risk of MS.

CONCLUSION

This study supports a statistically significant association between shift work at age 15-19 years and MS risk.

Main meal frequency measures in the Health Behaviour in School-aged Children study: agreement with 7-day 24-h recalls

OBJECTIVES

To estimate agreement between questionnaire-based frequency measures from the Health Behaviour in School-aged Children study (HBSC) and 7-day 24-h recall measures of breakfast, lunch and evening meals among 11-15-year-olds, and examine whether disagreement between the two methods varied by socio-demographic factors.

METHODS

In one week 11-15-year-old Danish students completed HBSC questionnaires including meal frequency items. The following week they completed daily 24-h recall questionnaire about their meals (response rate 88.4 %, n = 412).

RESULTS

Good to moderate agreement for the breakfast measure: per cent agreement 0.70-0.87, kappa 0.43-0.65. Fair agreement for the lunch measure: per cent agreement 0.53-0.84, kappa 0.26-0.54. High per cent agreement for the evening meal measure (0.83-0.95) but poor kappa agreement (0.14-0.19). Being immigrant predicted disagreement between the two methods for week day breakfast OR (95 % CI) 2.17 (1.16-4.04) and lunch 2.44 (1.33-4.48).

CONCLUSIONS

We found good to moderate agreement between frequency and 7-day 24-h recall measures for breakfast, a fair agreement for lunch and for evening meal the two agreement methods provided different results. Migration status predicted disagreement between the two methods.

Shaping the Social: design of a settings-based intervention study to improve well-being and reduce smoking and dropout in Danish vocational schools

Background

The social environment at schools is an important setting to promote educational attainment, and health and well-being of young people. However, within upper secondary education there is a need for evidence-based school intervention programmes. The Shaping the Social intervention is a comprehensive programme integrating social and educational activities to promote student well-being and reduce smoking and dropout in upper secondary vocational education. The evaluation design is reported here.

Methods/design

The evaluation employed a non-randomised cluster controlled design, and schools were selected to either implement the intervention or continue with normal practice for comparison. In the baseline survey conducted 2011–2012, 2,329 students from four intervention schools and 3,371 students from six comparison schools answered a computer-based questionnaire during class, representing 73 % and 81 % of eligible students, and 22 % of all technical/agricultural vocational schools in Denmark. Follow-up assessment was conducted 10 weeks after baseline and at the same time teachers of the intervention classes answered a questionnaire about implementation. School dropout rates will be tracked via national education registers through a 2-year follow-up period.

Discussion

Shaping the Social was designed to address that students at Danish vocational schools constitute a high risk population concerning health behaviour as well as school dropout by modifying the school environment, alongside developing appropriate evaluation strategies. To address difficulties in implementing settings-based interventions, as highlighted in prior research, the strategy was to involve intervention schools in the development of the intervention. Baseline differences will be included in the effectiveness analysis, so will the impact of likely mediators and moderators of the intervention.

Trials registration

ISRCTN57822968. Date of registration: 16/01/2013

Registers of multiple sclerosis in Denmark

There are two nationwide population-based registers for multiple sclerosis (MS) in Denmark. The oldest register is The Danish Multiple Sclerosis Registry (DMSR), which is an epidemiological register for estimation of prevalence and incidence of MS and survival, and for identifying exposures earlier in life that may affect the risk of MS. This register has no systematic follow-up data except for survival. The DMSR has over the years published nationwide incidence- and prevalence data from Denmark and has been involved in a number of 'historical prospective' studies to elucidate the association between a number of different environmental exposures in the past and the subsequent risk of MS. Some of these studies have been able to exonerate suspected risk factors. The other register, the nationwide Danish Multiple Sclerosis Treatment Register, is a follow-up register for all patients who have received disease-modifying treatments since 1996. It has, in particular, contributed to the knowledge of the role of antibodies against the biological drugs used for the treatment of MS.

Psychiatric co-morbidity in multiple sclerosis: The risk of depression and anxiety before and after MS diagnosis

BACKGROUND

Studies of depression and anxiety in multiple sclerosis (MS) patients have reported higher rates in MS patients than the general population.

OBJECTIVE

To estimate the risk of depression and anxiety and the use of tricyclic antidepressant and selective serotonin reuptake inhibitors (SSRI) prescriptions, in the pre-diagnostic and the post-diagnostic period of MS compared to the background population.

METHODS

A cohort of 5084 MS patients was included and matched with a control population of 24,771 persons linked to nationwide registers. Logistic regression analyses were performed estimating odds ratios (OR).

RESULTS

In the pre-diagnostic period, the OR for having a diagnosis of depression and anxiety is 1.4 (95% confidence interval (CI) =1.05-1.88), and the OR of redemption prescriptions of TCAs is 1.90 (CI=1.54-2.34) and OR is 1.34 (CI= 1.20-1.51) for SSRI. In the post-diagnostic period the OR is 1.23 (CI= 0.92-1.64) for depression and anxiety diagnosis. The OR is 6.70 (CI=5.81-7.72) for TCA and OR is 2.46 (CI= 2.25-2.69) for SSRI.

CONCLUSION

During both the pre- diagnostic and post-diagnostic period, MS patient have increased risk of depression and anxiety diagnoses and redemption of antidepressant and anxiolytic prescriptions, compared to the background population.

Gender effects on treatment response to interferon-beta in multiple sclerosis

BACKGROUND

Gender appears to play a role in incidence and disease course of multiple sclerosis (MS).

OBJECTIVE

The objective was to determine whether male and female patients with MS respond differently to interferon-beta treatment in terms of reduction in relapse rates.

METHODS

We included all 2033 patients with relapsing-remitting MS who started treatment with interferon-beta from 1996 to 2003, identified from the Danish Multiple Sclerosis Treatment Register. We defined neutralizing antibody (NAb)-positive and NAb-negative periods in the single patient by the results of the NAb tests. Patients served as their own controls, and relapse rates were compared between NAb-negative and NAb-positive periods.

RESULTS

NAbs significantly abrogated the interferon-beta treatment efficacy in both genders. The all-over women:men relapse rate ratio irrespective of NAb status was 1.47 (95%CI; 1.28-1.68). In a generalized linear Poisson models analysis with relapse counts as response variable, the main effects NAbs, sex, age at treatment start and number of relapses in 2 years before treatment start were strongly significant, but the effect of NAbs on relapse rates did not differ significantly between men and women.

CONCLUSION

As NAbs influenced the on-treatment relapse rates strongly in both sexes but without statistical significant difference, there is no indication of different effects of interferon-beta in men or women.

The use of epidemiological multiple sclerosis registers in research: the Danish MS Registry

INTRODUCTION

The claim of detection of several environmental risk factors for multiple sclerosis (MS), some of them new, makes the research of population-based MS registers for critical review or confirmation of alleged associations more relevant than ever before.

AIMS

To present examples of the use and important contributions from the Danish MS Registry (DMSR) over decades.

METHODS

The DMSR has through more than six decades registered virtually all patients with MS in Denmark, using multiple sources of notification and has been used for descriptive epidemiology, follow-up studies, studies of comorbidity and 'historical prospective' studies of proposed risk factors for MS.

RESULTS

Based on research from DMSR, we have found that female incidence of multiple sclerosis in Denmark has increased considerably; that patients with MS loose their working ability and their spouses/partners at a much higher rate than the background population; that patients with MS have a considerable excess mortality which seem to have decreased over several centuries decades - not centuries, also before the era of disease modifying treatment; that fewer patients with MS than expected from the population get diagnosed with or die from cancer; that infectious mononucleosis increases the risk of MS; that head trauma and a number of occupational exposures, for example, nurses, utility workers, exposure to solvents do not carry an enhanced risk of MS.

CONCLUSION

The DMSR has, as an example of long-lasting population-based registers, proven to be an effective tool for studying MS epidemiology. In future, the need for this kind of registers will continue, as biology or immunology cannot stand alone.

Childhood body mass index and multiple sclerosis risk: a long-term cohort study

BACKGROUND

Obesity in late adolescence has been associated with an increased risk of multiple sclerosis (MS); however, it is not known if body size in childhood is associated with MS risk.

METHODS

Using a prospective design we examined whether body mass index (BMI) at ages 7-13 years was associated with MS risk among 302,043 individuals in the Copenhagen School Health Records Register (CSHRR). Linking the CSHRR with the Danish MS registry yielded 774 MS cases (501 girls, 273 boys). We used Cox proportional hazards models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among girls, at each age 7-13 years, a one-unit increase in BMI z-score was associated with an increased risk of MS (HR(age 7)=1.20, 95% CI: 1.10-1.30; HR(age 13)=1.18, 95% CI: 1.08-1.28). Girls who were ≥95(th) percentile for BMI had a 1.61-1.95-fold increased risk of MS as compared to girls <85(th) percentile. The associations were attenuated in boys. The pooled HR for a one-unit increase in BMI z-score at age 7 years was 1.17 (95% CI: 1.09-1.26) and at age 13 years was 1.15 (95% CI: 1.07-1.24).

CONCLUSION

Having a high BMI in early life is a risk factor for MS, but the mechanisms underlying the association remain to be elucidated.

Absence from work due to occupational and non-occupational accidents

AIMS

The aim of the present study was to investigate absence from work in Denmark due to occupational and non-occupational accidents.

BACKGROUND

Since the beginning of the last decade, political focus has been placed on the population's working capacity and the scope of absence due to illness. Absence from work is estimated at between 3% and 6% of working hours in the EU and costs are estimated at approximately 2.5% of GNP.

METHODS

Victims of accidents treated at two emergency departments were interviewed regarding absence for the injured, the family and others. All answers were linked to the hospital information on the injury, so that it was possible to examine the relation between absence and injury type, and cause of the accident.

RESULTS

In total, 1,479 injured persons were interviewed. 36% of these reported absence from work by themselves or others. In mean, an injury caused 3.21 days of absence. Based on this the total absence due to injuries in Denmark was estimated to 1,822,000 workdays, corresponding to approximately 6% of the total absence from work due to all types of illness. Non-occupational injuries resulted in more absence than did occupational injuries.

CONCLUSIONS

Absence due to accidents contributed to a considerable part of the total absence from work, and non-occupational accidents caused more absence than did occupational accidents.

Are there differences in injury mortality among refugees and immigrants compared with native-born?

BACKGROUND

The authors studied injury mortality in Denmark among refugees and immigrants compared with that among native Danes.

METHOD

A register-based, historical prospective cohort design. All refugees (n=29, 139) and family reunited immigrants (n=27, 134) who between 1 January 1993 and 31 December 1999 received residence permission were included and matched 1:4 on age and sex with native Danes. Civil registration numbers were cross-linked to the Register of Causes of Death, and fatalities due to unintentional and intentional injuries were identified based on ICD-10 diagnosis. Sex-specific mortality ratios were estimated by migrant status and region of birth, adjusting for age and income and using a Cox regression model after a median follow-up of 11-12 years.

RESULTS

Compared with native Danes, both female (RR=0.44; 95% CI 0.23 to 0.83) and male (RR=0.40; 95% CI 0.29 to 0.56) refugees as well as female (RR=0.40; 95% CI 0.21 to 0.76) and male (RR=0.22; 95% CI 0.12 to 0.42) immigrants had significantly lower mortality from unintentional injuries. Suicide rates were significantly lower for male refugees (RR=0.38; 95% CI 0.24 to 0.61) and male immigrants (RR=0.24; 95% CI 0.10 to 0.59), whereas their female counterparts showed no significant differences. Only immigrant women had a significantly higher homicide rate (RR=3.09; 95% CI 1.11 to 8.60) compared with native Danes.

CONCLUSIONS

Overall results were advantageous to migrant groups. Research efforts should concentrate on investigating protective factors among migrants, which may benefit injury prevention in the majority population.

Long-term health effects of unintentional injuries in Danish adults

INTRODUCTION

The objective of the present study was to determine the prevalence of self-reported health effects of unintentional injuries in the adult Danish population, including the limitation of daily activities and perceived general health.

MATERIAL AND METHODS

In the 2005 National Health and Morbidity Survey in Denmark, 14,566 adults aged 16 years or more were asked about long-term health effects of unintentional injuries. Those reporting long-term health effects were asked about the type and duration of these effects and the accompanying limitation of their daily activities. Information on the external causes of injury was obtained by linking the interview data to the National Patient Register.

RESULTS

In total, 1,058 respondents (7.3%) reported health effects of injuries. Among these, 336 (2.3%) reported considerable limitations in their daily activities. Those reporting health effects also reported poor health in general. The most severe health effects affected the head, neck and back, as well as multiple body parts. Those injuries that entailed the most severe health effects were caused by traffic injuries and falls.

CONCLUSION

Long-term effects of injuries are prevalent in the adult population and most can be attributed to falls and traffic injuries. Back injuries and multiple injuries had the largest influence on perceived health.

FUNDING

The work was supported by TrygFonden grant no. 7585-07.

TRIAL REGISTRATION

not relevant.

Health service use in adults 20-64 years with traumatic brain injury, spinal cord injury or pelvic fracture. A cohort study with 9-year follow-up

OBJECTIVES

To estimate the health service use over 9 years after the injury year for patients with traumatic brain injury (TBI), spinal cord injury (SCI) and pelvic fracture (PF), and compare with non-injured.

DESIGN

A register-based cohort design with a 9-year follow-up period.

SETTING

The Danish population.

PARTICIPANTS

The study included 434, 100 and 278 hospital-treated incident patients with TBI, SCI and PF, respectively, among 20-year-olds to 64-year-olds identified using the National Patient Register. Controls for each patient group were drawn from the population register, matched by age, sex and health service use during 1995. All were followed during 1996-2005 by linkage to national health registers. The observations were excluded when the patients left Denmark or died.

OUTCOME MEASURES

The use of hospital treatments, contacts with general practitioners and the use of physiotherapy.

RESULTS

Compared to the controls, more patients with TBI and SCI were hospital admitted all 9 years after the injury year, on average 0.36 and 0.50 times annually, respectively. For patients with PF hospital admissions returned to baseline year 2 after the injury year. For patients with SCI the use of general practitioner services remained at an increased level year 9 after the injury year, while it returned to baseline level year 4 after the injury year for patients with TBI and year 2 for patients with PF. For patients with SCI physiotherapy use remained increased over 9 years after the injury year, while it returned to baseline the fifth year for patients with TBI and the third year after for patients with PF.

CONCLUSIONS

TBI and SCI increase the use of health services over 9 years after the injury year, while most health service use after PF returned to baseline 2 years after the injury year.

The Danish Injury Register

Introduction: The Danish Injury Register was established in 1988 and is based on injury case records from four Danish hospitals (five hospitals until 2007). Content: In total, 1.76 million cases were recorded during 1990—2008. Data items include the place of the accident, mechanism of injury, involved products, type of sports, and description of the accident. Validity and coverage: The register covers approximately 15% of the Danish population and is roughly representative for the whole Denmark in terms of age, sex, and social groups. Conclusion: The Danish Injury Register is a valuable source of information on injuries in Denmark, in particular product-related injuries and sports injuries. Further, the possibility to link to other registers increases the use of the data.

Unintentional injuries in children of Danish and foreign-born mothers

Aims: Unintentional injuries in children of foreign-born mothers were studied and compared with those in children of Danish-born mothers. Methods: A population of 173,504 children living in 32 municipalities in Denmark was followed from 1998 to 2003. Detailed information on childhood unintentional injuries from hospital records was linked to register data on parents’ education, country of origin, income, family type, etc. Poisson regression was used to analyse differences in injury risk between children of different origins. Results: We found 133,649 injuries, of which 15,389 occurred in children of foreign-born mothers. The injury rates in children of Western and non-Western origin were 0.83 (0.70—0.98) times and 0.84 (0.79— 0.90) times that of children of Danish-born mothers, respectively. The difference was largest in children of families with unemployed parents. The injury rate in girls of non-Western origin was 29% lower than in girls of Danish origin, while the rate in boys of non-Western origin was only 5% lower than in boys of Danish origin. This gender difference was particularly pronounced for sports and traffic injuries. Children of non-Western origin had a three-fold higher rate of burns caused by hot water, tea or oil than children of Danish origin. Conclusions: Prevention of injuries in children of non-Western origin should especially focus on scalds from tea, oil, and hot water.