Physical violence, self rated health, and morbidity: is gender significant for victimisation?

STUDY OBJECTIVE

To analyse gender differences in associations between physical violence and self rated health and self reported morbidity among a random sample of adults in Denmark.

DESIGN AND SETTING

Two questions on self rated health and self reported morbidity respectively, were obtained from a cross sectional national health interview survey conducted among 12 028 adults (16 years +) in Denmark in 2000. A question on six different forms of physical violence was obtained from a supplementary self administered questionnaire given to the same sample. The reporting period for experienced physical violence was the past 12 months and for morbidity symptoms, the past 14 days.

MAIN RESULTS

Men aged 16-24 years were significantly more likely to have experienced violence than women (OR = 3.2, 95% CI = 2.3 to 4.2). Female victims of physical violence were significantly more likely to rate their health as poor (OR = 2.02, 95% CI = 1.41 to 2.89) and to report anxiety (OR = 2.14, 95% CI = 1.35 to 3.37), depression (OR = 2.36, 95% CI = 1.55 to 3.60), and stomach ache (OR = 1.58, 95% CI = 1.01 to 2.47) than female non-victims. Male victims of physical violence were only significantly more likely to report stomach ache (OR = 1.73, 95% CI = 1.03 to 2.89) than male non-victims.

CONCLUSIONS

Associations between physical violence and poor self rated health and self reported morbidity were found to be significant for women, but not for men. It is probable that gender differences in experiences of violence, as well as gender differences in health related self perception, contribute to a gender specific process of victimisation. Improved knowledge about the relation between gender specific violence and victimisation as a gender specific consequence is essential for targeting violence prevention.

Vitamin A and sudden infant death syndrome in Scandinavia 1992-1995

AIM

To assess the effect of vitamin supplementation on the risk of sudden infant death syndrome (SIDS).

METHODS

The analyses are based on data from the Nordic Epidemiological SIDS Study, a case-control study in which parents of SIDS victims in the Scandinavian countries were invited to participate together with parents of four matched controls between 1 September 1992 and 31 August 1995. The odds ratios presented are computed by conditional logistic regression analysis.

RESULTS

The crude odds ratio in Scandinavia for not giving vitamin substitution was 2.8 (95% CI (1.9, 4.3)). This effect was statistically significant in Norway and Sweden, which use A and D vitamin supplementation, but not in Denmark, where only vitamin D supplementation is given. The odds ratios remained significant in Sweden when an adjustment was made for confounding factors (OR 28.4, 95% CI (4.7, 171.3)).

CONCLUSION

We found an association between increased risk of sudden infant death syndrome and infants not being given vitamin supplementation during their first year of life. This was highly significant in Sweden, and the effect is possibly connected with vitamin A deficiency. This effect persisted when an adjustment was made for potential confounders, includingsocioeconomic factors.

Breast feeding and the sudden infant death syndrome in Scandinavia, 1992-95

AIMS

To assess the effects of breast feeding habits on sudden infant death syndrome (SIDS).

METHODS

The analyses are based on data from the Nordic Epidemiological SIDS Study, a case-control study in which parents of SIDS victims in the Scandinavian countries between 1 September 1992 and 31 August 1995 were invited to participate, each with parents of four matched controls. The odds ratios presented were computed by conditional logistic regression analysis.

RESULTS

After adjustment for smoking during pregnancy, paternal employment, sleeping position, and age of the infant, the adjusted odds ratio (95% CI) was 5.1 (2.3 to 11.2) if the infant was exclusively breast fed for less than four weeks, 3.7 (1.6 to 8.4) for 4-7 weeks, 1.6 (0.7 to 3.6) for 8-11 weeks, and 2.8 (1.2 to 6.8) for 12-15 weeks, with exclusive breast feeding over 16 weeks as the reference. Mixed feeding in the first week post partum did not increase the risk.

CONCLUSIONS

The study is supportive of a weak relation between breast feeding and SIDS reduction.

International Child Care Practices Study: infant sleeping environment

BACKGROUND

The International Child Care Practices Study (ICCPS) has collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the infant sleeping environment with the main focus being sudden infant death syndrome (SIDS) risk factors (bedsharing and infant using a pillow) and protective factors (infant sharing a room with adult) that are not yet well established in the literature.

METHODS

Using a standardised protocol, parents of infants were surveyed at birth by interview and at 3 months of age mainly by postal questionnaire. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey.

RESULTS

Birth interview data were available for 5488 individual families and 4656 (85%) returned questionnaires at 3 months. Rates of bedsharing varied considerably (2-88%) and it appeared to be more common in the samples with a lower awareness of SIDS, but not necessarily a high SIDS rate. Countries with higher rates of bedsharing appeared to have a greater proportion of infants bedsharing for a longer duration (>5 h). Rates of room sharing varied (58-100%) with some of the lowest rates noted in centres with a higher awareness of SIDS. Rates of pillow use ranged from 4% to 95%.

CONCLUSIONS

It is likely that methods of bedsharing differ cross-culturally, and although further details were sought on different bedsharing practices, it was not possible to build up a composite picture of "typical" bedsharing practices in these different communities. These data highlight interesting patterns in child care in these diverse populations. Although these results should not be used to imply that any particular child care practice either increases or decreases the risk of SIDS, these findings should help to inject caution into the process of developing SIDS prevention campaigns for non-Western cultures.

Changes in the epidemiology of sudden infant death syndrome in Sweden 1973-1996

BACKGROUND

From the early 1970s to the early 1990s, there was a significant rise in the incidence of sudden infant death syndrome (SIDS) in Scandinavia. Following the risk reducing campaign, the incidence has fallen to about the same level as in 1973.

AIMS

To identify the changes that have occurred in the epidemiology of SIDS.

METHODS

We compared the Swedish part of the Nordic Epidemiological SIDS Study (NESS), covering the years 1992-1995, with two earlier, descriptive studies during this period. To assess the changing effects of risk factors, we analysed data from the Medical Birth Registry of Sweden, covering the years 1973-1996.

RESULTS

There was a predominance of deaths during weekends in the 1970s and 1990s. The seasonal variation was most notable in the 1980s. The proportion of young mothers decreased from 14% to 5%. Cohabitation (living with the biological father) was as frequent in the 1990s as in the 1970s. The prevalence of high parity, admissions to neonatal wards, low birth weight, prematurity, and multiple pregnancies were all increased in the 1990s compared to the 1970s. No significant change in the prevalence of previous apparent life threatening events was found. Deaths occurring in cars diminished from 10% to below 2%. In the data from the Medical Birth Registry of Sweden, there were significantly increased odds ratios after the risk reducing campaign of the risk factors smoking during early pregnancy and preterm birth. We could find no increased effects of maternal age, parity, or being small for gestational age over time. The rate of deaths at weekends remained increased; the median age at death fell from 90 to 60 days. Seasonal variation was less notable in the periods of low incidence.

Sex differences in mortality in Denmark during half a century, 1943-92

OBJECTIVE

The emphasis of this study is on the relative mortality of 45-74-year-old men and women in Denmark in 1943-92, following economic and political changes that have affected the social meaning of gender over the last 50 years, and which have diminished former sex differences in health behaviour.

METHODS

Sex ratios of total mortality and mortality from major non-sex-specific causes of death were calculated on computerized mortality data from the Danish National Cause of Death Register that covers all deaths in Denmark since 1943.

RESULTS

In the early 1940s the sex ratio of all-cause mortality was low, 1.0-1.1, it increased to a peak level in the late 1970s and early 1980s, but has since decreased due to an increase in female mortality and a more favourable trend in male mortality.

CONCLUSION

Gender equality, employment, and economic autonomy may have beneficial health effects on both men and women, but the effects are inconsistent. The trend in smoking is the major explanatory factor for the more recent trends in gender differentials in mortality in Denmark.

[What do we know about the extent of violence against women in Denmark?]

At present, figures about the prevalence of violence against women in Denmark are based upon regional studies from emergency departments and national surveys that included a few questions about violence. In 1995/96, 0.2% of women aged 16-74 reported to have been exposed to domestic violence during the last 12 months, the highest rate was among single mothers, 3.4%. In 1991, 3% of women above the age of 15 reported to have ever been victims of rape, 7% among 15-24 year-olds. In the period 1978-1994, between 1.4 and 4.5 permille of all emergency contacts were female victims of violence. The incidence was 1.6-3.5 per 1000 women, highest in the Copenhagen area and in the western part of Denmark. In other Nordic countries, national surveys have focused upon gender-based violence, and report a higher prevalence of violence than in the less focused Danish studies. Furthermore, these studies contain information about the health sequels of violence. There is an urgent need for similar data including risk factors of violence in Denmark in order to prevent violence and the health consequences of violence against women.

Living conditions in early infancy in Denmark, Norway and Sweden 1992-95: results from the Nordic Epidemiological SIDS study

The objective was to study living conditions of infants and their families in Scandinavia in the 1990s and to assess similarities and differences among the three Scandinavian countries. The emphasis is on health and normality rather than on diseases and other deviations from well-being. The subjects are the 869 controls in the Nordic Epidemiological SIDS study carried out between 1 September 1992 and 31 August 1995 in Norway, Denmark and Sweden. The controls were matched with the 244 SIDS cases for sex, age and maternity hospital. Parents of the SIDS cases and the controls filled in the same questionnaire on family, pregnancy, delivery, the neonatal and the post-perinatal period. The most striking findings were that 99% of the mothers went to regular maternity controls, 97% to well-baby clinics and 84% breastfed exclusively. On the other hand, 11% drank alcohol more than once a month during pregnancy and 29% smoked during pregnancy. Compared to official statistics, to the extent they exist, the differences were small. The material contains valuable information on normal infant care in Scandinavia in the 1990s. Living conditions of infants in Scandinavia are similar in the three countries. Differences exist, but only to a small extent.

The Danish registers of causes of death

In 1875 registration of causes of death in Denmark was established by the National Board of Health, and annual statistics of death have since been published. Until 1970 the national statistics were based upon punched cards with data collected from the death certificates. Since then the register has been fully computerized and includes individual based data of all deaths occurring among all residents in Denmark dying in Denmark. Furthermore, a microfilm of all death certificates from 1943 and onward is kept in the National Board of Health. The Danish Institute for Clinical Epidemiology (DICE) has established a computerized register of individual records of deaths in Denmark from 1943 and onwards. No other country covers computerized individual based data of death registration for such a long period, now 54 years. This paper describes the history of the registers, the data sources and access to data, and the research based upon the registers, presenting some examples of research activities.

Caffeine and alcohol as risk factors for sudden infant death syndrome. Nordic Epidemiological SIDS Study

OBJECTIVE

To assess whether alcohol and caffeine are independent risk factors for sudden infant death syndrome (SIDS).

MATERIALS AND METHODS

Analyses based on data from the Nordic epidemiological SIDS study, a case control study in which all parents of SIDS victims in the Nordic countries from 1 September 1992 to 31 August 1995 were invited to participate with parents of four controls, matched for sex and age at death. Odds ratios (ORs) were calculated by conditional logistic regression analysis.

RESULTS

The crude ORs for caffeine consumption > 800 mg/24 hours both during and after pregnancy were significantly raised: 3.9 (95% confidence interval (CI), 1.9 to 8.1) and 3.1 (95% CI, 1.5 to 6.3), respectively. However, after adjustment for maternal smoking in 1st trimester, maternal age, education and parity, no significant effect of caffeine during or after pregnancy remained. For maternal or paternal alcohol use, no significant risk increase was found after adjusting for social variables, except for heavy postnatal intake of alcohol by the mother, where the risk was significantly increased.

CONCLUSIONS

Caffeine during or after pregnancy was not found to be an independent risk factor for SIDS after adjustment for maternal age, education, parity, and smoking during pregnancy. Heavy postnatal but not prenatal intake of alcohol by the mother increased the risk.

Interactions of infectious symptoms and modifiable risk factors in sudden infant death syndrome. The Nordic Epidemiological SIDS study

The aim of the study was to investigate the effect of infection on sudden infant death syndrome (SIDS) and to analyse whether modifiable risk factors of SIDS, prone sleeping, covered head and smoking act as effect modifiers. In a consecutive multicentre case-control study of SIDS in Denmark, Norway and Sweden, questionnaires on potential risk factors for SIDS were completed by parents of SIDS victims, and for at least two controls matched for gender, age and place of birth. All SIDS cases were verified by an autopsy. The study comprised 244 SIDS cases and 869 controls, analysed by conditional logistic regression. Significantly more cases than controls presenting symptoms of infectious diseases during the last week and/or last day were treated with antibiotics and had been seen by a physician. The finding is consistent with the hypothesis of an infectious mechanism in SIDS induced by local microorganism growth and toxin or cytokine production, and also adds further support to a possible association between infection and SIDS by loss of protective mechanisms, such as arousal. The risk of SIDS among infants with the combined presence of infectious symptoms and either of the other modifiable risk factors, prone sleeping, head covered or parental smoking, was far greater than the sum of each individual factor. These risk factors thus modify the dangerousness of infection in infancy.

Drug-related mortality in Denmark 1970-93

We analysed drug-related mortality in Denmark with respect to secular trends, gender, and regional variations, for the period 1970-93, for all deaths from poisoning and among drug addicts. The study was based on the Register of Causes of Death in Denmark and included 6,229 drug-related deaths, defined by specific combinations of manner of death, underlying cause of death, and contributory cause of death. The main outcome measure is age-specific mortality rate. A total of 63% of the drug-related deaths were registered as unnatural deaths. During the period studied, mortality increased for men in the 25 49 year age group and for women in all age groups over 25 years of age. For both men and women, the youngest birth cohorts from the mid-1950s and 1960s suffered much higher mortality than those born before 1950; however, the three youngest birth cohorts had almost the same mortality. During the entire period, mortality in the capital, Copenhagen, was much higher than in the provinces, but in the last years, a more favourable trend has been seen in Copenhagen.

Sudden unexpected death in infancy: epidemiologically determined risk factors related to pathological classification

Infants that died suddenly and unexpectedly were studied as part of the European Concerted Action on sudden infant death syndrome (SIDS). Three paediatric pathologists, first independently of each other and later in a consensus meeting, classified 63 cases into 3 groups: SIDS (19 cases), borderline SIDS (30 cases) and non-SIDS (14 cases). The interobserver agreement among the pathologists before the consensus meeting was moderate (Kappa = 0.41) and jointly it was higher (Kappa = 0.83). The distribution of epidemiologically determined risk factors was studied over these three groups. Maternal smoking after birth, low socioeconomic status and thumb sucking were found more often in SIDS than in the other cases. Inexperienced prone sleeping was a determinant for SIDS, but not for non-SIDS. Previous hospital admission, low birthweight and/or short gestation were associated with borderline SIDS. Non-SIDS cases received more breastfeeding, the parents hardly smoked during pregnancy and after birth, a firm mattress had been used, and more often signs of illness had been reported by the parents, compared with the SIDS and borderline SIDS cases. Bedding factors and both primary and secondary prone sleeping were equally distributed over the three groups which supports the hypothesis that, in SIDS and borderline SIDS, as well as in non-SIDS cases, some similar external and preventable factors might influence the events leading to death. Research should therefore focus on all sudden unexpected deaths, after which subgroups such as SIDS cases can be separately analysed. The postmortem is an essential part of the whole work-up of each case and the results should be interpreted with all other available data to arrive at a sound evaluation of cases and thus form the basis for the prevention of all sudden unexpected infant death.

[Induced abortion and risk of breast cancer]

It has been hypothesized that an interrupted pregnancy might increase the risk of breast cancer, because proliferation of breast cells will take place without the protective effect of subsequent differentiation. In a cohort of 1.5 million women (28.5 million person-years) we identified 370,715 induced abortions in 280,965 women (2.7 million person-years) and 10,246 women with breast cancer. After adjustment for other risk factors, induced abortion was not associated with the risk of breast cancer (relative risk: 1.00; 95 percent confidence interval 0.94 to 1.06). However, the relative risk of breast cancer increased with increasing gestational age of the most recently induced abortion: < 7 weeks: 0.81; 7 to 8 weeks; 1.01; 9 to 10 weeks: 1 (reference); 11 to 12 weeks: 1.12; 13 to 14 weeks: 1.13; 15 to 18 weeks: 1.23; > 18 weeks: 1.89; P(trend) = 0.016. On a population basis, induced abortion was not associated with an increased risk of breast cancer. An increase was only seen for the special group of late second trimester abortions, but this finding was based on small numbers.

[The trend in induced abortions in Denmark until 1995. Illustrated by the relation to other data sources, preventive campaigns during the last years and the stage of pregnancy]

This study presents a review of the trend in the Danish abortion rate, with a view to prevention campaigns and introduction of electronic registration of abortions through the National Patient Registry. The number of induced abortions has been decreasing steadily since 1975; abortion on demand up to the end of 12th gestational week has been permitted by law in Denmark since 1973. The lowest number ever was registered in 1994 and 1995, corresponding to a rate of 13.7 per 1,000 women aged 15-49 years. The number per 1,000 liveborn decreased from 277 in 1993 to 253 in 1994. The relative number of abortions was highest among women aged 20-29 years, and in the capital area. Since 1993 the health authorities have strengthened campaigns to reduce the number of unplanned pregnancies, primarily focusing on younger women and with special programs in the capital area. The reduction for these groups could point to a success of the prevention campaigns, although the rates of terminated pregnancies might be influenced by many other factors.

A case-control study of smoking and sudden infant death syndrome in the Scandinavian countries, 1992 to 1995. The Nordic Epidemiological SIDS Study

AIM

To establish whether smoking is an independent risk factor for sudden infant death syndrome (SIDS), if the effect is mainly due to prenatal or postnatal smoking, and the effect of smoking cessation.

METHODS

The analyses were based on data from the Nordic epidemiological SIDS study, a case-control study with 244 cases and 869 controls. Odds ratios were computed by conditional logistic regression analysis.

RESULTS

Smoking emerged as an independent risk factor for SIDS, and the effect was mainly mediated through maternal smoking in pregnancy (crude odds ratio 4.0 (95% confidence interval 2.9 to 5.6)). Maternal smoking showed a marked dose-response relation. There was no effect of paternal smoking if the mother did not smoke. Stopping or even reducing smoking was beneficial. SIDS cases exposed to tobacco smoke were breast fed for a shorter time than non-exposed cases, and feeding difficulties were also more common.

CONCLUSIONS

Smoking is an independent risk factor for SIDS and is mainly mediated through maternal smoking during pregnancy. Stopping smoking or smoking less may be beneficial in reducing the risk of SIDS.

Sociodemographic risk factors for sudden infant death syndrome: associations with other risk factors. The Nordic Epidemiological SIDS Study

The aim of this study was to investigate associations between sudden infant death syndrome (SIDS) and social factors in the Nordic countries. A case-control study was conducted in Denmark, Norway and Sweden: The Nordic Epidemiological SIDS Study. Parents of 244 SIDS infants and 869 control infants matched on gender, age at death and place of birth filled in questionnaires. The dataset was analysed by conditional logistic regression. In univariate analysis, the following sociodemographic factors were associated with an increased risk of SIDS: low maternal age [odds ratio (OR) 7.8; 2.8-21.5], high birth order (OR 4.4; 2.5-7.5), single motherhood (OR 2.9; 1.7-5.0), low maternal education (OR 4.5; 2.8-7.1), low paternal education (OR 3.0; 1.9-4.7), maternal unemployment (OR 2.4; 1.8-3.4) and paternal unemployment (OR 4.0; 2.7-5.9). In a multivariate analysis where maternal smoking was also included, only paternal unemployment, young maternal age and high birth order remained significantly associated with SIDS. Housing conditions were not associated with SIDS. However, the risk of SIDS was high if the family had lived in their present home for only a few years (OR 2.3; 1.3-4.1). Sociodemographic differences remain a major concern in SIDS in a low-incidence situation and even in an affluent population with adequate health services.

Combined effects of sleeping position and prenatal risk factors in sudden infant death syndrome: the Nordic Epidemiological SIDS Study

OBJECTIVE

Prone sleeping is a strong risk factor for sudden infant death syndrome (SIDS). We investigated whether the combined effect of prone sleeping position and prenatal risk factors further increased the SIDS risk.

METHODS

In the Nordic Epidemiological SIDS Study, parents of SIDS victims in Denmark, Norway, and Sweden completed a questionnaire on potential risk factors for SIDS. Forensic pathologists verified the SIDS diagnosis. Four controls of the same gender, age, and place of birth were selected. This matched case-control study, which included 244 SIDS cases and 869 controls from 1992 to 1995, was analyzed by conditional logistic regression.

RESULTS

Odds ratios (ORs) for prone and side sleeping compared with supine sleeping for the last sleep were 13.9 (95% confidence interval 8.2-24) and 3.5 (2.1-5.7). Infants 13 to 24 weeks old had particularly high risk in prone and side sleeping, at 28.5 (7.9-107) and 5.9 (1.6-22). OR for prone sleeping was higher in girls, at 30.4 (11-88), than in boys, 10.3 (5.5-19). We found strong combined effects of sleeping position and prenatal risk factors (more than multiplicative). The OR for prone and side sleeping was increased for infants with birth weight <2500 g, at 83 (25-276) and 36.6 (13-107); for preterm infants, at 48.8 (19-128) and 40.5 (14-115); and for intrauterine growth retarded, at 38.8 (14-108) and 9.6 (4.3-22), compared with supine position in infants without these prenatal factors. The combined effect of nonsupine positions and intrauterine growth retarded was highest among 13- to 24-week-old infants. Effects of combined presence of nonsupine sleeping positions and each of the factors of smoking in pregnancy, young maternal age, higher parity, low level of maternal education, and single motherhood were more than additive. Attributable fractions in the population for prone and side sleeping were 18.5% and 26.0%.

CONCLUSIONS

Both prone and side sleeping increased the risk of SIDS. The risk was increased further in low birth weight infants, preterm infants, and infants at the age of 13 to 24 weeks, suggesting that SIDS may be triggered by nonsupine sleeping in infants with prenatal risk factors during a vulnerable period of postnatal development.

The decline in the incidence of SIDS in Scandinavia and its relation to risk-intervention campaigns. Nordic Epidemiological SIDS Study

A prospective case-control study of sudden infant death syndrome (SIDS) in Norway, Denmark and Sweden between September 1, 1992 and August 31, 1995 comprised 244 cases and 869 matched controls. After the introduction of risk-intervention campaigns, the SIDS incidence decreased from 2.3/1000 live births in Norway, 1.6 in Denmark and 1.0 in Sweden to 0.6/1000 or fewer in all the Scandinavian countries in 1995. The decrease paralleled a decline in the prone sleeping position and there was an accompanying parallel fall in total postneonatal mortality in all three countries. Thus, the risk-reducing campaigns for SIDS have been successful not only in Norway and Denmark, starting from relatively high incidences, but also in Sweden, starting from a low incidence. During the study period, a gradual increase was observed for the effects of prone sleeping, smoking and bottle-feeding as risk factors for SIDS.

[Reporting of induced abortions in 1994. A comparison between the data in the Registry of Legally Induced Abortions and the National Patient Registry]

Up to 31st December 1994 all cases of legally induced abortions were notified by the physician responsible for the operation to the National Board of Health and recorded in the Register of Induced Abortions. Following this data, abortion statistics will rely on data concerning induced abortions in the Danish National Patient Register, which includes information based upon the unique personal number of all patients admitted to hospitals. The completeness of the Register of Induced Abortions and the National Patient Register as to induced abortions in 1994 was assessed to evaluate the impact of the change in method of monitoring on trends in the national and regional abortion rate. The complete number of induced abortions was estimated to be the sum of the number recorded in both registers, cases recorded only in the Register of Induced Abortions, cases recorded only in the National Patient Register, and the missing number of registration of induced abortions calculated by capture-recapture methods. Of these 18,429 abortions 96.4% were registered in the National Patient Register and 93.5% in the Register of Induced Abortions. There were some regional variations. In some counties more abortions were registered in the Register of Induced Abortions and in others in the National Patient Register. Considering the change from 1995 in sources of the statistics of induced abortions, analyses of trends in the abortion rate in the early 1990s in Denmark must be evaluated with prudence.

Induced abortion and the risk of breast cancer

BACKGROUND

It has been hypothesized that an interrupted pregnancy might increase a woman's risk of breast cancer because breast cells could proliferate without the later protective effect of differentiation.

METHODS

We established a population-based cohort with information on parity and vital status consisting of all Danish women born from April 1, 1935, through March 31, 1978. Through linkage with the National Registry of Induced Abortions, information on the number and dates of induced abortions among those women was combined with information on the gestational age of each aborted fetus. All new cases of breast cancer were identified through linkage with the Danish Cancer Registry.

RESULTS

In the cohort of 1.5 million women (28.5 million person-years), we identified 370,715 induced abortions among 280,965 women (2.7 million person-years) and 10,246 women with breast cancer. After adjustment for known risk factors, induced abortion was not associated with an increased risk of breast cancer (relative risk, 1.00; 95 percent confidence interval, 0.94 to 1.06). No increases in risk were found in subgroups defined according to age at abortion, parity, time since abortion, or age at diagnosis of breast cancer. The relative risk of breast cancer increased with increasing gestational age of the fetus at the time of the most recent induced abortion: <7 weeks, 0.81 (95 percent confidence interval, 0.58 to 1.13); 7 to 8 weeks, 1.01 (0.89 to 1.14); 9 to 10 weeks, 1.00 >12 weeks, 1.38 (1.00 to 1.90) (reference category, 9 to 10 weeks).

CONCLUSIONS

Induced abortions have no overall effect on the risk of breast cancer.

[Perinatal mortality in Denmark. An analysis of development assessed in connection with medically induced abortion during the period 1980-1993]

Based upon data from the Danish National Register of Causes of Deaths, the Birth Register and registers on induced abortions and congenital malformations the article analyses the trend in the Danish perinatal mortality and the impact of abortions induced on medical grounds during the period 1980-1993. Estimating that half of the induced abortions might have led to a perinatal death it is concluded that the perinatal mortality would still have been significantly reduced from the late 1980s to 1990-1993. It is stressed that the impact of induced abortions be included in analyses of trends in perinatal mortality. The perinatal deaths are classified in nine categories by which a grouping into non-avoidable (unexplained intrauterine deaths and deaths due to congenital birth defects) and avoidable deaths (all other categories) was possible. The classification mixed pathoanatomical, obstetrical and paediatric criteria and facilitated an evaluation of the trend in mortality in relation to health care. The recent decrease in the overall perinatal mortality to 7.5 per 1.000 born was both due to a fall in deaths caused by prematurity and in deaths due to congenital birth defects. The deaths due to prematurity were not significantly linked to maternal smoking during pregnancy and no differences could be found in the overall prenatal screening between mothers who lost a baby due to malformations and all mothers.

[Infant mortality among children of 35-39 year-old mothers. An analysis of development of death cause categories and among multiple pregnancies during the period 1980-1993]

The perinatal mortality in Denmark decreased significantly from the late 1980's to 1990-1993 but increased among births by mothers aged 35-39 years, from 9.7 in 1985-1989 to 11.0 per 1000 born in 1990-1993. No increase was observed among infants of teen-age mothers or mothers older than 40 years. Based upon data from the Danish National Register of Causes of Death and the Birth Register all perinatal deaths in 1980-1993 were classified in nine categories including pathoanatomical, obstetrical and paediatric criteria. The increase in perinatal mortality in infants born to mothers aged 35-39 years was because of more deaths due to congenital birth defects, intra-partum events and foeto-placental dysfunction, while mortality due to prematurity decreased. The rate of multiple pregnancies and of primiparas increased significantly among 35-39 year-old mothers. With reference to international literature, the article discusses the possible impact of in-vitro fertilisation and other fertility treatments upon the special trend in perinatal mortality in this mother age-group. A national Danish IVF-register was first established in 1994 and will in the future allow concrete analyses of the outcome of IVF-pregnancies.

[Overheating and sudden infant death. Temperature regulation in relation to the prone position, the possible pathogenesis of sudden infant death]

The incidence of sudden infant death syndrome (SIDS) in Denmark varied in the period 1982-1991 between 1.5 and 1.9 per 1000 livebirths. In December 1991 recommendations concerning infants' sleeping position were published by The Danish National Board of Health in order to reduce the risk of SIDS. Babies were recommended to be placed in the supine or side position when sleeping. Parents have followed the guidelines. Most Danish infants are now sleeping on their back or in the side position. Simultaneously, the number of SIDS dropped from about 110 to 40 per year. The incidence decreased to 1.2 in 1992 and was further reduced in 1993 to 0.6 per 1000 live births. Referring to our knowledge of the infant's temperature regulation we discuss why the prone position is a risk factor for SIDS. The head is the site of up to 85% of heat loss in an infant in bed. Placed in the prone position, the infant is more likely to suffer a rise in body temperature, especially if this is combined with having a cold, being heavily wrapped and sleeping in a heated room. Preceding sudden death many infants are reported to have suffered from minor viral infections. These might per se increase the body temperature. Parents often wrap infants that have an infection too heavily, which in an infant sleeping in the prone position might increase the body temperature to a higher level than if sleeping supine. The body temperature influences the production of toxins from normal intestinal flora and from pathogenic bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Sudden natural death in childhood. A review of forensic autopsy protocols in cases of sudden death between the ages of one and five years, 1982-1991, with a special view to sudden unexplained death

All cases of sudden death of individuals between the ages of one and five years examined at the Forensic Institute, Copenhagen, in a 10-year period were identified to assess the impact of sudden unexplained death in this age group. Of a total of 68 cases, 27 cases were due to accidents, there were 13 cases of homicide, 27 cases were sudden natural deaths and in 1 case the manner of death was uncertain. The autopsy records and histological sections in the 27 cases of natural death were reviewed; the cause of death was not explained in 11 of these cases (40%). Seven cases were previously considered to be caused by infectious disease or aspiration. Criteria for classification are discussed.

The frequency of a disease-causing point mutation in the gene coding for medium-chain acyl-CoA dehydrogenase in sudden infant death syndrome

A number of rare inherited metabolic disorders are known to lead to death in infancy. Deficiency of medium-chain acyl CoA dehydrogenase has, on clinical grounds, been related particularly to sudden infant death syndrome. The contribution of this disorder to the etiology of sudden infant death syndrome is still a matter of controversy. The present study investigated 120 well-defined cases of sudden infant death syndrome in order to detect the frequency of the most common disease-causing point mutation in the gene coding for medium-chain acyl-CoA dehydrogenase (G985) compared with the frequency in the general population. A highly specific polymerase chain reaction assay was applied on dried blood spots. No over-representation of homo- or heterozygosity for G985 appears to exist in such a strictly defined population, for which reason it may be more relevant to look at a broader spectrum of clinical presentations of inherited metabolic disorders and examine a wider range of sudden death in infancy.

Sudden death and human insulin: is there a link?

Case reports from the United Kingdom (UK) in 1989 have suggested that the introduction of human insulin in 1985 was associated with an increased risk of sudden death in insulin-treated diabetic patients. If human insulin increases the risk of sudden death, the number of these should have increased during the period where human insulin was introduced. We therefore identified all cases of sudden death in Denmark in younger insulin-treated diabetic patients, age at death below 50 years. During this period the consumption of human insulin went from 0.2% to 70% of the total consumption in Denmark. The total number of cases fulfilling the inclusion criteria was 226, and the annual number of sudden deaths did not change during the study period (p = 0.14). The number of deaths due to hypoglycaemia and cases with unexplained cause of death also remained constant (test for trend: p = 0.44). Chronic alcohol abuse or acute alcohol intoxication was found in 50% of the 135 patients dying from hypoglycaemia, ketoacidosis or unknown cause of death (including found dead in bed), while this was the case in only 16% of the remaining 91 cases dying from other natural causes. We conclude that introduction of human insulin in Denmark was not followed by an increase in sudden deaths among younger insulin-treated diabetic patients.

[Sudden, unexplained infant death--sudden infant death syndrome. Forensic pathological aspects]

Delimitation of the sudden unexplained infant death syndrome (SIDS) is difficult as the diagnosis is made by exclusion. The difficulties in the differential diagnosis are concentrated on interpretation of the significance of positive viral and bacterial findings, inflammatory changes in the respiratory organs, heart and central nervous system together with malformations. Classification of SIDS appears, therefore, to vary according to time and place. New techniques, e.g. DNA analysis, have explained the etiology in a few per cent of the cases but have not yet solved the riddle of SIDS. The article reviews hypotheses about apnoea, arrhythmia, overheating and inefficient surveillance of the infant. It is emphasized that assessment of risk factors for SIDS requires valid epidemiological investigations where the basis for the diagnosis is a uniform classification of SIDS infants as compared with other groups of sudden death in infancy. An investigation of this nature has been initiated in the Nordic countries. It is important to examine and treat infants with abnormal sleep apnoea but generalized employment of monitoring has not reduced the number of unexplained infantile deaths.

[Significance of sleeping position on the occurrence of sudden, unexplained infant death. An epidemiological review]

The cause of the sudden infant death syndrome (SIDS) is, according to the definition, unknown. Epidemiological research during recent years has identified a series of probable risk factors. One of these is the use of prone position as sleeping position. In the Western European countries, Australia and New Zealand, a total of 14 case-control studies illustrate a possible connection between the prone position and SIDS. Eleven of the studies revealed a significantly increased relative risk (RR) of between 1.4 and 12.5 for SIDS when using the prone position, while the three remaining studies did not demonstrate increased RR. A meta-analysis of the results of the 14 case-control studies showed an RR of 2.4 for SIDS in the prone position as compared with other sleeping positions. In a single prospective cohort study from Australia, an RR of 3.1 was found for SIDS in the prone position. Interventions in which parents are advised not to place the infants in the prone position during sleep appear to have resulted in considerable reduction in the number of cases of SIDS according to preliminary reports from Great Britain, the Netherlands, Norway and New Zealand. A series of methodological problems can be demonstrated in the published results of these studies, including limited size of study populations, inadequate matching of control groups and absent confounder control. Nevertheless, the total epidemiological evidence, also where Denmark is concerned, speaks in favour of altered recommendations for sleeping positions of infants, particularly because there is no documentation to suggest that the prone position offers any advantages to health.(ABSTRACT TRUNCATED AT 250 WORDS)

Sudden infant death syndrome (SIDS) in Denmark: evaluation of the increasing incidence of registered SIDS in the period 1972 to 1983 and results of a prospective study in 1987 through 1988

To investigate a reported increase, from 0.4 to 1.3 per thousand live births, in the Danish incidence of sudden infant death syndrome (SIDS), a retrospective analysis of SIDS in Denmark from 1972 to 1983 was carried out. Based on data registered with the National Board of Health, a notable regional difference in SIDS rate between the western and eastern parts of Denmark was found. This difference did not correlate with the overall postneonatal mortality by region. Danish law requires medicolegal investigation in all cases of sudden unexpected death. Medicolegal autopsies are performed only in the three forensic institutes which cover all of Denmark. Despite the law and a uniform organization of the forensic medical services, differing application of postmortem examinations and individual interpretation of the history and autopsy in cases of sudden infant death existed. Differences in reporting of respiratory infections, suffocation, and cardiac malformation were found to contribute to the increase and to regional disparities in SIDS incidence. The three Danish forensic institutes examined all cases of sudden infant deaths in Denmark 1987 and 1988. These cases were classified as explained cause of death, pure SIDS, and atypical SIDS; atypical cases were evaluated by consensus. The SIDS incidence (the number of classic SIDS and atypical SIDS per thousand live births) was 1.9 in 1987 and 1.3 in 1988, and it was identical in the eastern and western part of Denmark; however, a higher incidence both of overall postneonatal and SIDS mortality was found in the middle region of Denmark.(ABSTRACT TRUNCATED AT 250 WORDS)

A perinatal audit of stillbirths in three Danish countries

All stillbirths in 1985 and 1986 in three Danish counties were assessed in a perinatal audit. The aim was to investigate if departure from generally accepted standards of satisfactory perinatal care might have contributed to stillbirths, and also to investigate if differences in the structure of antenatal care and the delivery systems might have any influence on the rate of stillbirths. 119 cases evaluated, 70 were classified as unavoidable deaths, in 48 cases a different treatment might have improved the infant's possibility of survival and in one case consensus was not reached. The most frequent cause of suboptimal care was inadequate antenatal care of obvious signs of intrauterine growth retardation. Directives for visitation between surgical and obstetric departments were essential to the rate of stillbirth. The results indicate that it might be possible to achieve a further decrease in the number of stillbirths by intensifying the postgraduate training of the professionals and by issuing guidelines for the sharing of care responsibilities.

[The quality of registration of causes of death in perinatal and neonatal deaths]

The quality of registration of the causes of death in 273 perinatal and neonatal deaths was assessed. The present authors classified the causes of death according to WHO classification of disease. The authors classification was compared with the Danish Health Department's original classification of deaths and a classification undertaken by one of the staff of the Danish Health Department, the coding of which was based exclusively on information from the original death certificates (death certificate classification). Agreement between the respective forms of classification was assessed by the observed agreement for positive diagnosis and the kappa coefficients calculated by the three-figure level in the ICD diagnosis for categories and between categories of causes of perinatal and neonatal death, respectively. The investigation revealed that the deaths were classified with great accuracy by coding by the staff member when the death certificates were correctly completed. Comparison between the "authors classification" and the "Danish Health Department's original classification" and the "death certificate classification", respectively revealed that the observed agreement for positive diagnoses were 52% and 50% and that the kappa coefficients were between 0.80-0.07 and 0.81-0.04, respectively, on comparison with the three-figure levels in the ICD diagnoses and 0.93-0.32 and 0.85 and 0.32 on comparing the categories in between. It is concluded that considerable improvement in registration of perinatal and neonatal deaths may be obtained if the Danish Health Departments states precisely what information is required on the death certificate in connection with perinatal and neonatal deaths. Correspondingly, local efforts should be made to complete death certificates more correctly.

[Classification of perinatal and neonatal deaths. Fetal, obstetrical and neonatal causes]

A new method of classification of causes of death which may be employed in connection with perinatal and neonatal deaths is presented. The classification of causes of death proposed by the authors identifies the factor which probably initiated the train of events leading to death. This classification includes nine main categories and illustrates foetal conditions, happenings in pregnancy, the course of delivery and also the neonatal period. Employment of classification is proposed in regional registration of perinatal and neonatal deaths and as an aid in the current assessment of the quality of antenatal, obstetric and neonatal care as these are employed in medical audits of the perinatal and neonatal deaths in many Danish counties.

Chlamydia and sudden infant death syndrome. A study of 166 SIDS and 30 control cases

Chlamydia inclusions could be demonstrated by an immunofluorescence assay in formalin-fixed lung sections in 32 of 166 cases (19.4%) of Sudden Infant Death Syndrome (SIDS) and in the lungs of only 1 of 30 infants with a known cause of death (3.3%). The difference is statistically significant (P = 0.04). Chlamydia trachomatis is an agent of pneumonia in 1-4 month-old infants who have acquired the disease from an infected cervix during birth, but other chlamydia species are also capable of causing pneumonia. The lung sections of the 32 chlamydia positive SIDS cases did not show typical histological signs of pneumonia. Even though chlamydia inclusions were detected in the lungs of 32 SIDS cases a causal relation between chlamydia infection and SIDS could not be demonstrated.

The medical component in fact-finding missions

Fact-finding missions (FFMs) are useful instruments in examining allegations of human rights violations. The United Nations Convention against Torture and other Cruel Inhuman or Degrading Treatment and the European Convention for the Prevention of Torture and Inhuman and Degrading Treatment or Punishment include the possibility for FFMs. The role of the medical profession in FFMs is discussed, and it is recommended that doctors should be included in FFMs to document allegations of torture and other human rights abuses.

[Frequency of causes of death related to sudden infant death syndrome in Denmark during the period 1972-1983]

Differences in the incidence of infant mortality due to sudden infant death syndrome between the regions of the three Institutes of Forensic Medicine in Denmark are known to exist. To investigate whether these could be due to differences in incidence of causes of death such as suffocation and respiratory infections, the rates and types of autopsy were analysed regarding these death causes. The number of deaths due to these causes and the development in the incidence cannot explain the variation of the incidence of SIDS, in the areas observed. For each of the three periods under consideration (1972-1975, 1976-1979, 1980-1983) the variation between institutes in SIDS-rate is relatively larger than the variation in the total rate of deaths due to these three groups of death causes. In the latest period the total rate is 1.93, 1.77 and 1.27 per 1,000 liveborn in Cophenhagen, Odense and Arhus areas, respectively. The study suggests different evaluations of the results of autopsy. A higher incidence of deaths due to congenital heart defects is seen in Arhus, where the lowest incidence of SIDS is observed. A prospective study (1987-1988) of all cases of sudden infant death in Denmark was initiated by the three forensic Institutes with the aim of evaluating possible time and regional incidence variations using identical diagnostic criteria.

Injuries due to deliberate violence in areas of Denmark. V. Violence against women and children. Copenhagen Study Group

As part of an European-South American study of deliberate violence cases of violence against women greater than or equal to 15 years of age and violence against and among children under the age of 15 years were registered at 3 Danish emergency wards and at the Institute of Forensic Medicine in Copenhagen. 352 cases of violence against women and 46 cases of violence against children were registered in the three emergency wards corresponding to rates of about 1.6/1000 per year for women, 0.6/1000 per year for boys and 0.7/1000 per year for girls in a provincial/rural district, the catchment region of Holbaek County Hospital, 3.4/1000 per year for women, 2.8/1000 per year for boys and 0.6/1000 per year for girls in a mainly middle income area of the metropolis Copenhagen, the catchment region of Frederiksberg Hospital, and 4.0/1000 per year for women, 4.0/1000 per year for boys and 0.9/1000 per year for girls in a mainly low income area of Copenhagen, the catchment region of the Rigshospital. Nineteen live adult female victims and 17 dead adult female victims of violence were registered in the Institute of Forensic Medicine in Copenhagen, where also one was registered as a victim of homicide. Nearly half of the adult live female victims of violence had been injured at home while this was the case for approximately three fourth of the dead victims. In 35% of the live cases the husband was the aggressor and in 12% a former cohabitant. In 71% of the homicide cases the husband was the aggressor. The live women appeared to have fewer but more serious lesions than men. The pattern of deliberate violence against women appears to be associated with socio-economic and cultural factors. In cases with a preceding quarrel there is statistically a link to alcohol intoxication. In half of the cases of violence against children the aggressor was known to the victim, in 15% the aggressor was one of the parents, while 42% of the cases were violence among children. The pattern of violence according to sex, and the distribution and severity of lesions for 10-14 years old children showed resemblance to the situation for adults. The lesions were more serious in young infant victims, especially boys, than in adult victims.

Injuries due to deliberate violence in areas of Denmark. III. Lesions. The Copenhagen Study Group

As part of a transcultural investigation of violent behavior in Denmark and South America, the lesions from accidents involving deliberate violence registered in three Danish emergency wards during a 1-year period were studied. A quantity of 2211 lesions were diagnosed in 1316 patients (953 male and 363 female patients). Sixty-five percent of the lesions were in the head/neck region, 13% in truncus, 18% in the upper extremities and 5% in the lower extremities. The most frequent diagnosis was an open wound in the head/neck region. Adding contusions and fractures in the same region this amounted to more than half of the total number of lesions. In the upper extremities 62% of the lesions were contusions or open wounds. Serious lesions of internal arteries were few, however always caused by sharp instruments (knives). Serious lesions due to firearms were not recorded/reported. Strangulation had been used against 1.1% of the victims, the male/female ratio being 1:6. The main part of the lesions were of minor severity when assessed on the basis of the scores in the Abbreviated Injury Scale (AIS). The lesions were, however, more serious compared to other recent studies, and it appeared that the female victims had fewer but more serious lesions than the male victims. The need for treatment and hospitalization was in the range of other recent studies.

Injuries due to deliberate violence in areas of Denmark. IV. Alcohol intoxication in victims of violence. The Copenhagen Study Group

A material of 1316 victims of deliberate violence was collected prospectively during a one year period in three Danish emergency wards covering a provincial/rural area and two metropolitan areas. The frequency of alcohol intoxication was determined. Forty-one percent of the patients were intoxicated. The highest frequency was found in male victims, in the provincial/rural area, in restaurants or their vicinity, in the age group 35-49, during evenings and nights and in May. It is difficult to indicate specific preventive measures. However, a more restrictive attitude is suggested with regard to serving alcohol to intoxicated persons in restaurants.

Injuries due to deliberate violence in areas of Denmark. II. Victims of homicide in the Copenhagen area

As part of a transcultural investigation of injuries due to deliberate violence in Denmark and South America, homicides in the Copenhagen area were studied for a 1-year period. Forty-five cases corresponding to a rate of approximately 2/10(5) per year were recorded. The rate seems to be increasing and the pattern changing with a higher frequency of stabbing and with an increasing frequency of high blood-alcohol concentrations in the victims. The highest number were killed at home. In the majority of cases the aggressor and the victim knew each other. A reduction in alcohol consumption is indicated as a possible preventive measure.

Injuries due to deliberate violence in areas of Denmark. I. The extent of violence

As part of a transcultural investigation of violent behavior in Denmark and South America an analysis was made during a one year period of the incidents involving deliberate violence as registered at 3 Danish emergency wards, and at the Institute of Forensic Medicine in Copenhagen. In the three emergency wards a total of 1316 victims of deliberate violence were observed corresponding to a rate of about 3.3/1000 per year in a provincial/rural district, the catchment region of Holbaek County Hospital, 5.5/1000 per year in a mainly middle income area of the metropolis Copenhagen, the catchment region of Frederiksberg Hospital, and 7.6/1000 per year in a mainly low income area of Copenhagen, the catchment region of the Rigshospital. The highest risk, 28/1000 per year, was found for young men between 15 and 19 years of age living in the low income area of Copenhagen. The risk was low for people greater than or equal to 60 years of age in all three areas investigated, ranging from 0 (men) to 1.3/1000 per year (women). Skilled and unskilled workers were greatly over represented as victims of violence, considering their share of the background population. Seventy percent of the victims were men. At least 44% of the men and 32% of the women were alcohol intoxicated when arriving in the emergency ward. The incidents took place in restaurants or in the vicinity of restaurants for 30% of the male and 11% of female victims respectively, while 45% of the women had been subject to deliberate violence at home. The rate of fatal cases of deliberate violence in the Eastern part of Denmark, the catchment area for the Institute of Forensic Medicine in Copenhagen, was found to be 0.02/1000 per year. The risk of becoming a victim of deliberate violence has not increased during the last 4 years comparing with similar investigations from other parts of Denmark. However, the rate of homicide seems to have increased, and so has the severity of the injuries caused by deliberate violence. The pattern of deliberate violence appears to be associated with socio-economic and cultural factors, and to be closely linked with alcohol intoxication.