Suicide in young Norwegians in a life course perspective: population-based cohort study.

BACKGROUND: Suicide is a leading cause of death in young adults. Several risk factors are well known, especially those related to adult mental health. However, some risk factors may have their origin in the very beginning of life. This study examines suicide in the general Norwegian population in a life course perspective, with a main focus on early life factors. METHODS: In this study, several national registers were linked, supplying personal data on biological and social variables from childhood to young adult age. Participants were all Norwegians live born during the period 1967-1976, followed up through 2004. Persons who died or emigrated before the year of their 19th birthday, at which age follow-up started, were excluded. Thus, the study population comprised 610 359 persons, and the study outcome was completed suicide. RESULTS: 1406 suicides (0.23%) were recorded, the risk being four times higher in men than in women. Suicide risk factors included not being firstborn (adjusted HR in men and women (95% CIs): 1.19 (1.05 to 1.36) and 1.42 (1.08 to 1.88)), instability of maternal marital status during childhood, parental suicide (mainly in women), low body mass index (only investigated in men), low education and indications of severe mental illness. CONCLUSIONS: Suicide in young adults may be rooted in early childhood, and the effect is likely to act through several mechanisms, some of which may be linked to the composition and stability of the parental home. A life course perspective may add to our understanding of suicide.

Job adjustment and absence from work in mid-pregnancy in the Norwegian Mother and Child Cohort Study (MoBa).

BACKGROUND: Pregnant women at work have special needs, and sick leave is common. However, job adjustment in pregnancy is addressed in European legislation. Our main objective was to examine if job adjustment was associated with reduced absence. METHODS: This study is based on the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. 28,611 employed women filled in questionnaires in weeks 17 and 30 in pregnancy. The risk of absence for more than 2 weeks was studied among those who were not absent in week 17 (n = 22,932), and the probability of return to work in week 30 among those who were absent in week 17 (n = 5679). Data were based on self-report. The influence of job adjustment (three categories: not needed, needed but not obtained, needed and obtained) was analysed in additive models in multivariable binomial regression. Associations with other job characteristics and work environment factors were also analysed. RESULTS: The risk of absence for more than 2 weeks was 0.308 and the probability of return to work was 0.137. Compared with women who needed but did not achieve job adjustment, obtained job adjustment was associated with a 0.107 decreased risk of absence (95% confidence interval 0.090 to 0.125) in a model including other job characteristics and work environment factors. Job adjustment was correspondingly associated with a 0.041 (0.023 to 0.059) increased probability of return to work. Absence was associated with adverse work environment, whereas the opposite pattern was found for return to work among those who started off being absent. CONCLUSIONS: Job adjustment was associated with reduced absence from work in pregnancy. Results should be interpreted cautiously because of low participation in MoBa and potential information bias from self-reported data.

[More and more young people on disability pensions]. / Stadig flere unge uføretrygdede.

BACKGROUND: A considerable increase was noticed in Norway over the 1990s in the incidence of persons below 34 drawing disability pensions. In certain communities, the number almost tripled from 1992 to 1997. MATERIAL AND METHODS: In order to study the causes of this increase, we examined all applications for disability pension from persons below 34 in the years 1992 and 1997 drawn from 19 selected local communities all over Norway, a total of 239 files. Social and medical variables and elements of the application procedure were registered and subjected to statistical analysis. RESULTS: Apart from the medical diagnoses used, there were only small differences between the characteristics of applicants in the two years under study. The number of persons with a psychiatric diagnosis was, however, considerably higher in 1997 than in 1992, in relative as well as in absolute terms. INTERPRETATION: We cannot say for certain whether the higher number of applicants registered with a mental disorder really reflects an increase in such disorders among young people, but the observations may reflect a higher incidence, probably caused by more pressure in the workplace in terms of competition and the level of qualifications required.

The association of Apgar score with subsequent death and cerebral palsy: A population-based study in term infants.

OBJECTIVE: To estimate the risk of adverse outcomes for newborns with a low Apgar score. STUDY DESIGN: Population-based cohort study. All 235,165 children born between 1983 and 1987 in Norway with a birth weight of at least 2500 g and no registered birth defects were followed up from birth to age 8 to 12 years by linkage of 3 national registries. Outcomes were death and cerebral palsy (CP). RESULTS: Five-minute Apgar scores of 0 to 3 were recorded for 0.1%, and scores of 4 to 6 were recorded for 0.6% of the children. Compared with children who had 5-minute Apgar scores of 7 to 10, children who had scores of 0 to 3 had a 386-fold increased risk for neonatal death (95% CI: 270-552) and an 81-fold (48-138) increased risk for CP. If Apgar scores at both 1 and 5 minutes were 0 to 3, the risks for neonatal death and CP were increased 642-fold (442-934) and 145-fold (85-248), respectively, compared with scores of 7 to 10. CONCLUSION: The strong association of low Apgar scores with death and CP in this population with a low occurrence of low scores shows that the Apgar score remains important for the early identification of infants at increased risk for serious and fatal conditions.

[Height, weight and body mass index measured among men born 1967-80]. / Høyde, vekt og kroppsmasseindeks ved sesjon for menn født i årene 1967-80.

BACKGROUND: Statistics Norway has published data on the average height of conscripts since 1910. Average height of men was 171.4 cm in 1920 and increased by 7.3 cm to 178.7 cm in 1970. Over the last 30 years, average height has increased only 1 cm, to 179.7 cm in 2000. The concern now is the fact that the average body weight of conscripts has been increasing. To monitor this development, statistics, based on BMI would be warranted. MATERIAL AND METHODS: The basis for such a statistics is explored in a study including all men born 1967-1980 known to the Norwegian central population registry as of December 1997; a total of 475,076 men. Data from the medical examinations for military service were obtained from the National Service Administration for 413,051 (86.9%). Of these men 400,297 (96.9%) were born in Norway, 12,754 abroad. RESULTS: The proportion of men born in Norway who were not examined averaged 6.4%. This percentage was much the same for each cohort. The reasons for being exempted from examination were the same, this indicates that there was no difference in selection bias between cohorts. No data were available for the assessment of the reliability and validity of the measurements. Nevertheless, trends in average height, weight and BMI give a clear picture of changes that have occurred. INTERPRETATION: Provided that validity of the measurements can be secured, it is concluded that examinations for military service can offer useful data for a health index on the growth and development of young men.

Becoming a disability pensioner with rheumatoid arthritis in Norway 1971-1990.

OBJECTIVE: Physically demanding occupations have been associated with becoming a disability pensioner with rheumatoid arthritis (DPRA), but not with the disease of RA. The association with becoming DPRA probably reflects that patients with RA have difficulties in maintaining employment in a physically demanding occupation. However, the attitudes of the employers concerning employment of persons with RA might vary. For example, the patient's age may influence the strength of the association between a physically demanding occupation and becoming DPRA. We assessed whether the association between the predictors and becoming DPRA was stronger for the youngest or the oldest age group. METHODS: The study was prospective with data on persons in Norway 30-56 years old either in the census of 1970 or 1980. All new cases of DPRA during the 2 followup periods 1971-80 and 1981-90 were identified and analyzed by logistic regression. RESULTS: For women the predictors employment, low level of education, and period ( 1981-90 compared to 1971-80) were more strongly associated with becoming DPRA for the youngest compared to the oldest persons, while manual work and part time work were not predictors of becoming DPRA. For men, all the predictors in the study were more strongly associated with becoming DPRA for the youngest compared to the oldest age group. CONCLUSION: The higher risk of becoming DPRA was associated with most predictors for persons aged 30-39 years than the group aged 50-56 years. Our results appear to indicate that the consequences of having RA in the labor market are greater for the youngest age group.

Permanent impairments, disabilities and disability pensions related to accidents in Norway.

The purpose of this study was to estimate the burden of accidents in terms of new disability pensioners related to accidental injuries in Norway and to use this information to supplement the picture of the epidemiology of accidents in Norway. The basis of the study was 7,241 new disability pensioners due to accidents in the Disability Register of the National Insurance Administration in Norway for 1992-1997. Included in the analyses are some data from health surveys in USA and Norway. The rate of disability pensioners (16-66 years old) due to accidents increased 4% annually during 1992-1997, and in the age group 16-44 years 8% annually. The increase is found in all types of accidents, except for home and the group other accidents, where the rate is constant. 45% had been injured in traffic accidents, 33% in occupational accidents, 16% in leisure accidents, 4% in home accidents and 2% in other accidents. The rates of disability pensionings due to occupational accidents are three to four times higher among 'blue collar' workers than among 'white collar' workers. While disability pensioning rate in the age group 16-66 years due to accidents has increased 4% annually, the accident mortality for the age group 15-64 years has decreased 3% annually. The relationship between disability pensioning and mortality in the age group 15-64 years is found to be approximately 2:1 for all accidents. For occupational accidents the relationship is 5:1, for traffic accidents 2.5:1, for leisure and other accidents 1:1 and for home accidents 1:2.7. The complete epidemiologic picture due to accidents in Norway per 100,000 of population seems to be: medically treated, 10,000; hospitalised, 1,200; permanently impaired, 800 (of whom probably 50% are treated as out-patients); disabled (restricted activity), 400; fatalities, 40; and disability pensioned in the age group 16-66 years, 50. Medically treated and hospitalised patients due to accidents seem to show a slightly decreasing rate, fatalities a higher decreasing rate. This supplement to the epidemiological picture of rates and trends of impairments, disability and disability pensionings (the more serious consequences of accidents), points to the need to focus on the current trends for accident prevention.

[Geographic variation in body mass index measured among men born in Norway between 1967-80]. / Geografiske variasjoner i kroppsmasseindeks målt ved sesjon for menn født i Norge 1967-80.

BACKGROUND: Conscripts born in 1980 were only 0.2 cm higher but weighed on average 3.3 kg more than those born in 1967. This weight gain corresponds to an average increase of body mass index (BMI) of 0.92 kg/m2. A description of geographical differences in changes of BMI is given. MATERIAL AND METHODS: All men born in Norway 1967-80, with Norwegian citizenship and known county of residence at the age of 18 are included, a total of 399,512 men. BMI was calculated for each birth cohort on the basis of data from the medical examinations for military service obtained from the Central Service Administration. RESULTS: Significant geographical differences in changes of BMI were found. Conscripts from Northern Norway had the largest increase of BMI, 2.0 kg/m2. The percentage of conscripts from Northern Norway with a BMI > or = 30 kg/m2 (obesity) increased from 1.5 for those born in 1967 to 6.5 for those born 13 years later. The smallest weight gain was observed among conscripts from the central counties of southeastern Norway; their average BMI increased only 0.5 kg/m2. The geographical differences became evident in the 1973-76 birth cohorts and are present also among the more recent birth cohorts. INTERPRETATION: To disclose the causes of these differences would be important in the prevention of overweight in young men.

Socioeconomic factors and disability retirement from back pain: a 1983-1993 population-based prospective study in Norway.

STUDY DESIGN: A prospective observational study with an 11-year follow-up period was performed. OBJECTIVE: To investigate the influence of education and socioeconomic position on the incidence of permanent disability retirement from back pain. SUMMARY OF BACKGROUND DATA: Early retirement because of back pain is the extreme end point of a disabling process that is a great burden to the individual and costly for the society. Groups of employees at particular risk for permanent back pain disability need to be identified. METHODS: All employed men and women in Norway between the ages of 20 and 53 years in 1980 were included (n = 1,333,556). Outcome measures were disability retirement from inflammatory back pain (ICD-9 code 720) and noninflammatory back pain (ICD-9 codes 721 to 724). RESULTS: The 11-year cumulative incidence was 0.15% (n = 1990) for disability retirement from inflammatory back pain and 1. 64% (n = 21,829) for noninflammatory back pain and was somewhat higher in women than in men. Each year of formal education was independently associated with decreased risk for disability retirement from noninflammatory back pain (odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.77-0.79) and from inflammatory back pain (OR = 0.83; 95% CI = 0.81-0.86). Whereas disability from inflammatory back pain was moderately associated with socioeconomic status, there was a consistent upward trend in the association between disability retirement from noninflammatory back pain and lower socioeconomic position. The OR for unskilled workers was 3.1 (95% CI = 2.6-3.7) for men and 2.1 (95% CI = 1.7-2.5) for women, as compared with that of higher professionals. Stepwise analyses suggest that the effect of education is not mediated by socioeconomic status. CONCLUSIONS: The consistent upward trend in the relation of disability retirement to lower levels of education and socioeconomic position, even for inflammatory back pain, shows that factors related to the occupational and social environment play an important role in the disabling process. The stepwise, monotonic relation between socioeconomic position and disability retirement from back pain, even at the higher end of the socioeconomic scale, suggests that the relation between social class and back pain disability cannot be explained solely in terms of manual versus nonmanual jobs.

Manual work as predictor for disability pensioning with osteoarthritis among the employed in Norway 1971-1990.

BACKGROUND: Manual work is reported to be a risk factor for becoming a disability pensioner due to osteoarthritis. This association may be due to covariation with other variables. We wanted to assess if manual work remained a risk factor after adjusting for number of hours worked, income, level of education, gender and marital status, and if the risk associated with manual work was equal in the 1970s and the 1980s. METHODS: In a prospective study, data on all new disability pensioners with osteoarthritis in Norway during the two follow-up periods, 1971-1980 and 1981-1990, were analysed by logistic regression. The study include data on all subjects living in Norway and registered as 50-56 years old and employed either in the census collected in 1970 or in the census of 1980. RESULTS: Manual workers have nearly twice the probability of becoming a disability pensioner with osteoarthritis compared to professionals after adjusting for part-time work, income, level of education, marital status and gender. Adjusted for other risk factors, the probability of becoming a disability pensioner with osteoarthritis was three times higher in the 1980s compared to the 1970s. CONCLUSION: The relatively strong association between manual work and disability pensioning with osteoarthritis suggests difficulties in adjusting manual work patterns for a person with osteoarthritis, which may have increased during the study period as implied by the separate effect of the 1980s.

[Applications for disability benefits before and after the 1991 restrictions]. / Søknader om uførepensjon før og etter innstrammingen i 1991.

In 1991, the eligibility criteria for disability benefits were restricted in Norway. Some effects are described in the present evaluation. Based on documents, first time applicants in 1990 and in 1993 in two counties were analysed according to social and medical variables. "Social security careers" before application are described, and proposals from physicians and the local social security office are compared with the decisions made by the county social security administration. Over a three-month period, applications decreased from 2.2 per 1,000 inhabitants in 1990 to 1.4 in 1993, a 39% decrease. About the same decrease was observed in all social and diagnostic groups. The proportion on vocational rehabilitation before application increased from 19% to 23% (p = 0.02). The certifying physicians proposed refusals in 9% and 8% in the two samples, and the local social security office did so in 12% and 13%. The refusal rate increased from 8% in 1990 to 21% in 1993. Refusals were mostly given to women, the middle-aged, those living alone, those with short education, and applicants with medically unclear conditions. It is pointed out that the restrictions on disability benefits in 1991 had the greatest impact on applicants with few resources.

[Sources of income after being denied disability pension]. / Kilder til livsopphold etter avslag på søknad om uførepensjon.

Restrictions in eligibility criteria for disability pension were introduced in Norway in 1991. The effect of these restrictions on sources of income is an important question in social policy. 157 first time applicants from two counties who were denied disability pension before (1990) and after (1993) the restrictions were studied three years later. Sources of income were established through searches in registers of wages and social security benefits. NOK 3,000 per month was set as the lowest income allowing economic independence. Of the applicants in 1990, 14% were in the workforce three years later. In the post-restriction 1993 sample, this proportion was 21% (p = 0.29). The proportions receiving disability pension were 25% and 22% respectively. The spouse supported 33% of the 1990 applicants, and 22% in the 1993 sample (p = 0.13). Social welfare was the main source of income for 6% and 10% (p = 0.25). Changes in main sources of income following the restriction were relatively small. The main result of this study is that family support is the most prevalent source of income when disability benefits are denied. This is not in accordance with the Government's policy of promoting gainful employment.

[Early identification of children with increased risk of permanent occupational disability]. / Tidlig identifisering av barn med økt risiko for varig arbeidsuførhet.

In Norway, disability pensioning of young adults is increasing. Provided that early habilitation is available, early identification of children at risk might be a measure to counteract this tendency. This conclusion can be drawn from a study including all newborns 1967-72 who were residents in Norway at the age of 24, a total of 380,142 persons. One out of four who received basic grant/attendance benefit in childhood was disability pensioned before the age of 25. On the other hand, nearly half of the 24-year-olds drawing disability pension had not received any previous assistance from the social security system in childhood. Thus, additional methods should be employed in the early identification and habilitation of children at high risk of developing permanent disability. A formalised co-operation between parents, the local health services, humanitarian organisations and the local social security office assisted by the Medical Birth Registry of Norway might contribute to the prevention of permanent disability in young age.

[Disability pensions in young age in Norway during 1976-1996]. / Uførepensjonering i ung alder i Norge i årene 1976-96.

A 15% increase in the incidence of 16 to 24-year olds drawing disability pension was observed in Norway from 1976 to 93. This increase is mainly a consequence of the higher numbers of pensioners because of birth defects and mental retardation. Prevalence of these conditions, which are clearly related to pregnancy, delivery, and inheritable disorders, may have increased as a consequence of the improved survival of newborn babies observed during the last two decades. A 50% increase in the incidence of disability pensions among 16 to 24-year olds has occurred in the three-year period from 1994 to 96. The higher rate is most probably a consequence of the restrictions in rehabilitation benefits introduced in 1993, and the resultant difficulties in obtaining employment. The higher incidence is a clear indicator of the need to increase assistance for the disabled in order to avoid their being pensioned at a young age.

Job adjustment as a means to reduce sickness absence during pregnancy.

OBJECTIVES: This study examined the effect of job adjustment on sickness absence during pregnancy and also determined the conditions under which such adjustments are obtained. METHODS: Data were derived from a nationally representative survey on work conditions during pregnancy in Norway in 1989. For employees (N = 2713) remaining in the same job throughout pregnancy, the percentage of women on sick leave immediately before delivery was determined according to the need for job adjustment and the obtainment of job adjustment. Those obtaining job adjustment were grouped according to workplace size, labor-market sector, co-worker gender, educational level, work schedules, weekly workhours, children under 16 years of age in the household, and age. RESULTS: All told, 1691 women (62.3%) needed job adjustment, among whom 936 (55.4%) obtained such adjustment. The proportions of those on sick leave before delivery were 45.2% for "no need", 67.9% for "need - adjustment obtained", and 79.2% for "need - adjustment not obtained". In the last category, the difference (versus "adjustment obtained") constituted 44.5% of the weeks lost because of sickness absence in the last half of pregnancy. The odds ratio (OR) for obtaining job adjustment was larger for workplaces with more than 50 employees (OR 1.4) and smaller for jobs with work schedules other than daytime or shift work (OR 0.5) and also for women living with children under 16 years of age (OR 0.8). CONCLUSIONS: Job adjustment is associated with reduced sickness absence during pregnancy. Further studies should explore workplace characteristics that make it difficult to obtain such adjustments, as required by law.

Work load, job control and risk of leaving work by sickness certification before delivery, Norway 1989.

Sickness absence in pregnancy has been shown to be associated with strenuous working conditions and parity. So far, few studies have made adjustments for possible interaction and confounding. Such adjustments are needed to more precisely identify targets for preventive measures. We have, therefore, in a representative population of pregnant employees in Norway 1989, computed adjusted odds ratios for leaving work by sickness absence more than three (LSC > 3) and eight (LSC > 8) weeks before delivery according to working conditions identified as risk factors in earlier studies; adjusted for job control, domestic conditions and sickness absence the year prior to pregnancy. The cumulative percentage of LSC > 8 and LSC > 3 was 26.4 and 51.1. Ergonomically strenuous postures and heavy lifting increased the risk of both outcomes. In addition, shift work and hectic work pace increased the risk of LSC > 3. Influence on breaks reduced risk. Only para experienced reduced risk of LSC when working part-time. Sicklisting the year prior to pregnancy had no confounding effect, which suggest that pregnancy represents a new incompatibility with work. Preventive measures should address work postures and heavy lifting, as well as conditions influencing the woman's control with her time.

Environmental factors, reproductive history, and selective fertility in farmers' sibships.

In a national study of births to farmers in Norway, grain farming was associated with short gestational age (21-24 weeks). An impact of selective fertility and maternal heterogeneity on the association was suspected but could not be assessed further in a traditional birth-based design. Thus, analyses based on the mother as the observational unit were performed. A total of 45,969 farmers with a first birth in 1967-1981 were followed for subsequent births and perinatal mortality. A perinatal loss increased farmers' likelihood to continue to another pregnancy, but this selective fertility was less dominant than in the general population due to a higher baseline fertility. The effect of the mother's reproductive history on the grain farming-midpregnancy delivery association was analyzed in 59,338 farmers with more than one single birth in 1967-1991. A history of preterm birth (< 37 weeks) in previous or subsequent pregnancies both was an independent determinant of midpregnancy delivery and also increased the effect of grain exposure. Nongrain farmers with a history of only term births had 1.3 midpregnancy deliveries per 1,000 births; grain farmers with a history of only term births had 1.8 cases per 1,000 (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.0-1.9); nongrain farmers with a history of preterm birth had 6.8 cases per 1,000 (OR 5.5, 95% CI 4.0-7.6), whereas grain farmers with a history of preterm birth had 13.7 cases per 1,000 (OR 11.0, 95% CI 7.7-15.9). Selective fertility had only a marginal impact on the association. The study demonstrates that a maternally based design can contribute in the assessment of joint effects of environmental and maternal factors.

PIP: Analyses based upon the mother as the observational unit were performed subsequent to findings from a national study which found grain farming among farmers in Norway to be associated with birth at gestational age 21-24 weeks. 45,969 farmers with a first birth in 1967-81 were followed for subsequent births and perinatal mortality. A perinatal loss increased farmers' likelihood to continue to another pregnancy, but such selective fertility was less dominant than in the general population due to a higher baseline fertility. The effect of the mother's reproductive history on the grain farming-midpregnancy delivery association was analyzed in 59,338 farmers with more than one single birth in 1967-91. A history of birth at under 37 weeks gestation in previous or subsequent pregnancies was an independent determinant of mid-pregnancy delivery and also increased the effect of grain exposure. Nongrain farmers with a history of only term births had 1.3 midpregnancy deliveries per 1000 births, grain farmers with a history of only term births had 1.8 cases per 1000, nongrain farmers with a history of preterm birth had 6.8 cases per 1000, and grain farmers with a history of preterm birth had 13.7 cases per 1000. Selective fertility had only a marginal impact upon the association. A biologically plausible explanation is that a maternal factor which increases the probability of preterm birth also increases one's susceptibility to the exposure factor in grain farming.

Occupation-specific morbidity of musculoskeletal disease in Norway.

The aim of this study was to investigate the occupation-specific prevalence of musculoskeletal disease in Norway. A cross-sectional interview survey of a representative sample of households in Norway in 1985, including 6,681 persons, 16 to 66 years old was carried out. Age-standardised, occupation-specific prevalence ratios for musculoskeletal disease were calculated. Musculoskeletal diseases were more frequent in women (20.6%) than men (17.3%), and increased markedly with age. In men, the prevalence was highest for construction carpenters; in women, for manufacturing/construction workers. In both male and female occupations, the highest prevalence of musculoskeletal diseases was approximately two-fold that of the lowest. Health-related exits from the labour force, and mobility between occupations influenced the results. It is suggested that the high disability pensioning and sickness absence rates observed in some occupations are related to occupation-specific consequences of disease in addition to higher morbidity.

[Use of occupational disease benefits]. / Bruk av yrkesskadetrygd ved yrkessykdom.

Persons with pleuramesothelioma were studied to find out the share receiving occupational injury benefit from the National Insurance Scheme. This disease, caused by inhaling asbestos, was chosen because it has been estimated that between 70 and 80 per cent of persons with pleuramesothelioma fulfil the criteria for compensation. During the period 1970-93, 662 men and 104 women were recorded as having this disease. Up to June 1996, the National Insurance Administration had considered the cases of only 163 men, and no women. A further 25-30 patients may have filed claims with the local national insurance office. This implies that, overall, maximum one third of those entitled to occupational injury benefit have received it. The fraction would probably be even lower in the case of diseases where the association with occupation is less certain. It is recommended that national disease registries, such as the Cancer Registry, should report possible cases of occupational disease to the National Insurance Administration.