Separable and controlled direct effects for competing events: Estimation of component specific effects on sickness absence.

In many settings, it is reasonable to think of treatment as consisting of a number of components, either because this is the case in practice or because it is conceptually possible to decompose treatment into separate components due to the way in which it exerts effects on the outcome of interest. For competing events, the treatment decomposition idea has recently been suggested to separate effects of treatments on the outcome of interest from effects mediated through competing events using so-called separable effects. Like the idea of separating effects of exposure, it has been pointed out that ideas from mediation analysis generally may help to clarify the interpretation of existing estimands used in competing events settings. One example is the use of the controlled direct effect, to conceptualize the effects of interventions preventing the competing event from occurring. In this article, we identify the controlled direct effect as a component specific effect and discuss the merits of this estimand when the prevented event is non terminal and other methods of effects separation are problematic. Our motivating example is the study of a policy initiative, introduced in 2001, aimed at reducing long term sickness absence (SA) in Norway. The initiative consists of different components, one being to encourage use of graded SA, which is considered a key tool in the Nordic countries to reduce long term SA. The analysis makes use of longitudinal registry data for 113 808 individuals, followed from the time of first SA.

Hearing Loss and Annual Earnings Over a 20-Year Period: The HUNT Cohort Study.

OBJECTIVES: The association between hearing loss and income has only been examined in cross-sectional studies. We aim to study annual increase in earnings over 20 years, comparing people with and without hearing loss. DESIGN: We used data from a population-based hearing study in Norway (The Trøndelag Health Study, 1996-1998), including 14,825 persons (46.2% men, mean age at baseline 30.6 years, age range 20 to 40 years). Hearing loss was defined as the pure-tone average threshold of 0.5 to 4 kHz in the better hearing ear ≥20 dB HL (n = 230). Annual earnings were assessed from 1997 to 2017. Longitudinal analyses were performed with linear mixed models adjusted for age, sex, and education. RESULTS: People without hearing loss at baseline (before age 40) had a greater annual increase in earnings over a 20-year follow-up period compared with people with hearing loss. For people with normal hearing, annual earnings over 20 years increased by 453 Euro (EUR) (95% confidence interval [CI] = 384 to 522) or 13.2% more per year than for people with hearing loss, adjusted for age and sex. The difference in annual earnings over 20 year was greater among women (462 EUR, 95% CI = 376 to 547) than men (424 EUR, 95% CI = 315 to 533), greater among younger than older adults, and greater among lower than higher educated persons. When including adjustment for education in the model, in addition to age and sex, the difference in annual earnings over 20 years between persons with and without hearing loss was reduced (337 EUR, 95% CI = 269 to 405). CONCLUSIONS: The results from this large population-based study indicates that people with hearing loss experience lower long-term earnings growth compared with people with normal hearing. The findings highlight the need for increased interventions in the workplace for people with hearing loss.

Association of child neurodevelopmental or behavioural problems with maternal unemployment in a population-based birth cohort.

PURPOSE: To estimate associations between suspected or diagnosed neurodevelopmental or behavioural problems in 7-year-old children and maternal unemployment at child age 7 and 10, in a Portuguese birth cohort. METHODS: We evaluated 5754 mothers and their children of the population-based birth cohort Generation XXI in Porto, Portugal. Data on suspected and diagnosed child neurodevelopmental and behavioural problems (exposures)-learning, attention and language problems, externalising behaviours, developmental delay, autism spectrum disorders, and other neurodevelopmental problems-were retrieved at 7 years of age by interviewing caregivers. Maternal employment status (outcome) was collected at the 7- and 10-year follow-up waves. Robust Poisson regression models were used to estimate associations. RESULTS: After adjustment for maternal and household characteristics, women were more likely to be unemployed at child age 10 if the child had, up to age 7, any of the following suspected problems: an autism spectrum disorder (PR = 1.73; 95% CI 1.07, 2.79), developmental delay (PR = 1.58; 95% CI 1.20, 2.06), externalising behaviours (PR = 1.29; 95% CI 1.11, 1.50) or learning problems (PR = 1.26; 95% CI 1.07, 1.48). When the exposure was restricted to clinically diagnosed disorders, the magnitude of associations remained similar but estimates were less precise. Associations with unemployment were stronger at child age 10 (prospective analyses), than at child age 7 (cross-sectional). CONCLUSION: Having a child with learning, developmental or behavioural problems, or an autism spectrum disorder up to age 7 was associated with maternal unemployment three years later, even in a less affluent European economy where the dual-earner family structure is often necessary to make ends meet.

Occupational variation in incidence of oropharyngeal cancer in the Nordic countries.

PURPOSE: Evaluate the occupational variation in incidence of oropharyngeal cancer (OPC). METHODS: We calculated standardized incidence ratios (SIRs) of OPC in occupational categories in the Nordic countries relative to the entire national populations. The data covered 6155 OPC cases. RESULTS: Among men high risk of OPC was observed, among else, in waiters (SIR 6.28, 95% CI 4.68-8.26), beverage workers (SIR 3.00, 95% CI 1.72-4.88), and artistic workers (SIR 2.97, 95% CI 2.31-3.76). Among women high risk of OPC was observed in waiters (SIR 2.02, 95% CI 1.41-2.81) and packers (SIR 1.73, 95% CI 1.07-2.64). The lowest SIRs were observed in female gardeners (SIR 0.27, 95% CI 0.12-0.51) and male farmers (SIR 0.30, 95% CI 0.25-0.35). CONCLUSION: The 20-fold variation in incidence of OPC between occupations needs further investigation in studies with detailed information on occupational and non-occupational risk factors.

Incidence of cancer among Nordic police officers.

Police work may expose officers to various circumstances that have potential for increasing their risk of cancer, including traffic-related air pollution, night shift work and radiation from radars. In this study, we examined the incidence of cancer among Nordic male and female police officers. We utilize data from the Nordic Occupational Cancer (NOCCA) project, which linked census data on occupations from Finland, Iceland, Norway and Sweden to national cancer registries for the period 1961 to 2005. We report standardized incidence ratios (SIR) and 95% confidence intervals (CI) of selected cancers for each country by sex, age and calendar period. The cohort included 38 523 male and 1998 female police officers. As compared with the general population, male police officers had a 7% (95% CI: 4-9%) excess cancer risk, with elevated SIRs for various cancer sites, including prostate (SIR 1.19, 1.14-1.25), breast (SIR 1.77, 1.05-2.80), colon (SIR 1.22, 1.12-1.32) and skin melanoma (SIR 1.44, 1.28-1.60). Conversely, male police officers had a lower risk of lung cancer than the general population (SIR 0.72, 0.66-0.77). In female police officers, the SIR for cancer overall was 1.15 (0.98-1.34), and there was a slight excess of cancers of the breast (SIR 1.25, 0.97-1.59) and colon (SIR 1.21, 0.55-2.30). In conclusion, cancer incidence among the police officers was slightly higher than in the general population. Notably, SIRs were elevated for cancer sites potentially related to night shift work, namely colon, breast and prostate cancer.

Relative Age Within School Grade, Including Delayed and Accelerated School Start: Associations With Midlife Psychiatric Disorders, Suicide, and Alcohol- and Drug-Related Mortality.

Within a school grade, children who are young for grade are at increased risk of psychiatric diagnoses, but the long-term implications remain understudied, and associations with students who delay or accelerate entry underexplored. We used Norwegian birth cohort records (birth years: 1967-1976, n = 626,928) linked to records in midlife. On-time school entry was socially patterned; among those born in December, 23.0% of children in the lowest socioeconomic position (SEP) delayed school entry, compared with 12.2% among the highest SEP. Among those who started school on time, there was no evidence for long-term associations between birth month and psychiatric/behavioral disorders or mortality. Controlling for SEP and other confounders, delayed school entry was associated with increased risk of psychiatric disorders and mortality. Children with delayed school entry were 1.31 times more likely to die by suicide (95% confidence interval: 1.07, 1.61) by midlife, and 1.96 times more likely to die from drug-related death (95% confidence interval: 1.59, 2.40) by midlife than those born late in the year who started school on time. Associations with delayed school entry are likely due to selection, and results thus underscore that long-term health risks can be tracked early in life, including through school entry timing, and are highly socially patterned.

Cancer incidence among visual artists: 45 years of follow-up in four Nordic countries.

INTRODUCTION: Professional visual artists constitute a heterogeneous vocational group, including, but not limited to painters, photographers, textile artists, and sculptors who may face exposure to workplace hazardous substances and lifestyle factors that may contribute to the development of selected cancers. The objective of this registry-based cohort study was to assess the cancer incidence among Nordic visual artists. MATERIALS AND METHODS: This study is based on data from the Nordic Occupational Cancer (NOCCA) project that combines census data of 15 million people from all Nordic countries and cancer registries from 1961 to 2005. For the present study we selected a cohort of visual artists from Finland, Iceland, Norway, and Sweden. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates. RESULTS: In male visual artists, there were statistically significant excesses in cancers of the tongue (SIR 2.91, 95% confidence interval 1.74-4.55), oral cavity (2.09, 1.26-3.27), pharynx (2.18, 1.45--3.15), testis (1.91, 1.11-3.05), renal pelvis (2.48, 1.42-4.03) and bladder (1.33, 1.14-1.55). The risk was significantly decreased for cancers of the lip (0.45, 0.18-0.93) and stomach (0.65, 0.50-0.84). In female visual artists, the only significantly increased risk was observed for breast cancer (1.29, 1.13-1.48) and the only significantly decreased risk for stomach cancer (0.43, 0.17-0.88). The incidence of lung cancer was close to the population average in both sexes. CONCLUSIONS: The non-elevated incidence of lung cancer suggests a similar prevalence of smoking between visual artists and the general population, while the elevated risk of cancers of mouth and pharynx among male visual artists is suggestive of more widespread alcohol drinking. The excess risk of urogenital cancers might be associated with exposure to solvents.

The exposure of visual artists to carcinogens remains unstudied and equivocal. The current study suggests that visual artists carry an overall cancer risk that is slightly above the risk among the general population of the four Nordic countries. We observed in men over two-fold excess risks of cancers of the tongue, oral cavity, pharynx, and renal pelvis, and also a significant risk of testis and bladder cancers.

Occupational variation in the incidence of lip cancer in the Nordic countries.

INTRODUCTION: While certain occupations, such as agriculture and fishery, have been associated with an increased risk of lip cancer, the occupational risk profile of lip cancer and its change over time remain poorly known. This study aims to evaluate the incidence of lip cancer across different occupations in the Nordic countries. METHODS: The Nordic Occupational Cancer Study (NOCCA) covers 14.9 million people and includes 45 years of cancer incidence data, from 1961 to 2005, linked to occupational categories for all the five Nordic populations. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used to quantify the risk of lip cancer across occupational categories relative to the entire national populations. RESULTS: There were a total of 14,477 male and 3008 female lip cancer patients identified during follow up. The highest SIRs were observed among male fishermen (SIR 2.26, 95% CI: 2.04-2.50), gardeners (SIR 1.60, 95% CI: 1.48-1.72), and farmers (SIR 1.60, 95% CI: 1.55-1.66). A significantly reduced risk of lip cancer (SIR < 0.50) was observed among male physicians, teachers, religious workers, artistic workers, journalists, administrators, printers, waiters, and hairdressers. Among women, no occupations were associated with an increased risk of lip cancer. CONCLUSIONS: The incidence of lip cancer varies widely between outdoor and indoor occupations. Occupations involving outdoor activity and exposure to sunlight show the most elevated SIRs.

Certain outdoor occupations, such as agriculture and fishery, have been associated with an increased risk of lip cancer. However, the occupational risk profile of lip cancer and its change over time remain poorly known. This study highlights the excess risk of lip cancer among men with outdoor occupations and further corroborates previous studies. Efforts to counsel outdoor workers on the risk and prevention of lip cancer are needed to reduce the societal burden of the disease.

Recognition of COVID-19 with occupational origin: a comparison between European countries.

OBJECTIVES: This study aims to present an overview of the formal recognition of COVID-19 as occupational disease (OD) or injury (OI) across Europe. METHODS: A COVID-19 questionnaire was designed by a task group within COST-funded OMEGA-NET and sent to occupational health experts of 37 countries in WHO European region, with a last update in April 2022. RESULTS: The questionnaire was filled out by experts from 35 countries. There are large differences between national systems regarding the recognition of OD and OI: 40% of countries have a list system, 57% a mixed system and one country an open system. In most countries, COVID-19 can be recognised as an OD (57%). In four countries, COVID-19 can be recognised as OI (11%) and in seven countries as either OD or OI (20%). In two countries, there is no recognition possible to date. Thirty-two countries (91%) recognise COVID-19 as OD/OI among healthcare workers. Working in certain jobs is considered proof of occupational exposure in 25 countries, contact with a colleague with confirmed infection in 19 countries, and contact with clients with confirmed infection in 21 countries. In most countries (57%), a positive PCR test is considered proof of disease. The three most common compensation benefits for COVID-19 as OI/OD are disability pension, treatment and rehabilitation. Long COVID is included in 26 countries. CONCLUSIONS: COVID-19 can be recognised as OD or OI in 94% of the European countries completing this survey, across different social security and embedded occupational health systems.

Weaker association between hearing loss and non-employment in recent generations: the HUNT cohort study.

OBJECTIVES: To examine the prevalence of hearing loss (HL) among employed persons, the association between HL and non-employment, assessing whether this has changed over the last two decades. To identify susceptible groups for HL-related work problems and examine the association between HL and co-worker relations. DESIGN: Cross-sectional analyses of working-age participants (20-66 years). HL was defined as the pure-tone average threshold of 0.5-4 kHz in the better hearing ear: 20-34 dB (mild) or ≥35 dB (disabling). Associations were assessed with logistic regression. STUDY SAMPLE: Data from two waves of the Trøndelag Health Study (HUNT): HUNT2 1996-1998 (N = 38,603), HUNT4 2017-2019 (N = 19,614). RESULTS: The nationally weighted prevalence of HL among employees was 5.8%. HL was associated with non-employment, more strongly in HUNT2 (odds ratio (OR) 2.2, 95% confidence interval (CI) 2.0-2.4) than HUNT4 (OR 1.9, CI 1.7-2.1). HL was not associated with poorer co-worker relations. The association between HL and non-optimal work performance was stronger among white-collar workers than blue-collar workers. CONCLUSIONS: Our study shows that HL is common in the employed population. It also indicates a weakened association between HL and non-employment in recent generations. White-collar workers appear to be more vulnerable to HL-related work problems than blue-collar workers.

This paper evaluates employment and work performance among hearing impaired. We show a prevalence of hearing loss (HL) among employed persons of 5.8% and that HL is associated with higher odds of non-employment. Our study indicates that the association between HL and non-employment has weakened in recent generations.

Occupational noise exposure and tinnitus: the HUNT Study.

OBJECTIVE: We aimed to assess the association between occupational noise exposure and tinnitus. Further, to assess whether the association depends on hearing status. DESIGN: In this cross-sectional study, tinnitus (>1 h daily) was regressed on job exposure matrix (JEM)-based or self-reported occupational noise exposure, adjusted for confounders. STUDY SAMPLE: The 14,945 participants (42% men, 20-59 years) attended a population-based study in Norway (HUNT4, 2017-2019). RESULTS: JEM-based noise exposure, assessed as equivalent continuous sound level normalised to 8-h working days (LEX 8 h), over the working career or as minimum 5 years ≥85 dB) was not associated with tinnitus. Years of exposure ≥80 dB (minimum one) was not associated with tinnitus. Self-reported high noise exposure (>15 h weekly ≥5 years) was associated with tinnitus overall and among persons with elevated hearing thresholds (prevalence ratio (PR) 1.3, 1.0-1.7), however not statistically significantly among persons with normal thresholds (PR 1.1, 0.8-1.5). CONCLUSIONS: Our large study showed no association between JEM-based noise exposure and tinnitus. This may to some extent reflect successful use of hearing protection. High self-reported noise exposure was associated with tinnitus, but not among normal hearing persons. This supports that noise-induced tinnitus to a large extent depends on audiometric hearing loss.

Occupational risk variation of nasopharyngeal cancer in the Nordic countries.

BACKGROUND: The aim of this study was to estimate occupational risk variation in the incidence of nasopharyngeal cancer (NPC) in a large population-based cohort of the Nordic Occupational Cancer (NOCCA) study. METHODS: This study is based on a cohort of almost 15 million persons from Denmark, Finland, Iceland, Norway and Sweden, with 2898 nasopharyngeal cancer cases diagnosed in 1961-2005. The data on occupations were gathered from population censuses and cancer data from the national cancer registries. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were estimated using the national NPC incidence rates as the reference. RESULTS: There were 1980 male and 918 female NPC patients. The highest SIRs of NPC were observed among male waiters (SIR 3.69, 95% CI 1.91-6.45) and cooks and stewards (SIR 2.24, 95% CI 1.16-3.91). Among women, launderers had the highest SIR of NPC (2.04, 95% CI 1.02-3.65). Significantly decreased SIRs were found among male farmers (SIR 0.79, 95% CI 0.68-0.92) and male textile workers (SIR 0.49, 95% CI 0.22-0.93). CONCLUSIONS: This study suggests that NPC may be associated with several work-related exposure agents such as smoking, kitchen air pollution and solvents. In future, occupational exposure-risk relations should be studied to understand more about causality and to assess effective prevention strategies.

The long-term effect of job mobility on workers' mental health: a propensity score analysis.

OBJECTIVES: The main purpose of this longitudinal study was to elucidate the impact of external job mobility, due to a change of employer, on mental health. METHODS: A cohort of Belgian employees from the IDEWE occupational medicine registry was followed-up for twenty-seven years, from 1993 to 2019. The use of drugs for neuropsychological diseases was considered as an objective indicator of mental health. The covariates were related to demographic, physical, behavioural characteristics, occupational and work-related risks. Propensity scores were calculated with a Cox regression model with time-varying covariates. The PS matching was used to eliminate the systematic differences in subjects' characteristics and to balance the covariates' distribution at every time point. RESULTS: The unmatched sample included 11,246 subjects, with 368 (3.3%) that changed their job during the baseline year and 922 (8.2%) workers that left their employer during the follow-up. More than half of the matched sample were males, were aged less than 38 years old, did not smoke, were physically active, and normal weighted, were not exposed to shift-work, noise, job strain or physical load. A strong association between job mobility and neuropsychological treatment was found in the matched analysis (HR = 2.065, 95%CI = 1.397-3.052, P-value < 0.001) and confirmed in the sensitivity analysis (HR of 2.012, 95%CI = 1.359-2.979, P-value < 0.001). Furthermore, it was found a protective role of physical activity and a harmful role of job strain on neuropsychological treatment. CONCLUSIONS: Our study found that workers with external job mobility have a doubled risk of treatment with neuropsychological medication, compared to workers without job mobility.

Hearing loss, sick leave, and disability pension: findings from the HUNT follow-up study.

BACKGROUND: Evidence on the association between hearing loss and sick leave or disability pension is to a great extent based on few cross-sectional studies and remains unclear. We aim to assess the associations in a long-term follow-up population study. METHODS: We used baseline data from a large population-based hearing study in Norway, the HUNT Hearing study (1996-1998). The sample included 21 754 adults (48.5% men, mean age at baseline 36.6 years). We used register data on sick leave and disability pension (1996-2011). Cox regression was used to assess the association between hearing loss at baseline (Pure tone average/PTA 0.5-4 kHz > 20 dB) and time to first physician-certified sick leave episode, as well as time to first disability pension payment. RESULTS: Hearing loss at baseline (yes/no) was weakly associated with time to first physician-certified sick leave episode: Hazard ratio (HR) 1.2 (95% confidence interval (CI) 1.1-1.3). Restricting the exposed group to people with both hearing loss and tinnitus, the HR was slightly increased: 1.3 (95% CI 1.1-1.6). Hearing loss in 1996-1998 was also associated with time to first received disability pension: HR 1.5 (95% CI 1.3-1.8). Stronger associations were found for disabling hearing loss (PTA > 35). Restricting the exposure to hearing loss and tinnitus, the HR was increased: 2.0 (95% CI 1.4-2.8). CONCLUSIONS: This large population-based cohort study indicates that hearing loss is associated with increased risk of receiving disability pension, especially among younger adults and low educated workers. Hearing loss was weakly associated with sick leave.

Migrant workers occupational health research: an OMEGA-NET working group position paper.

OBJECTIVE: The aims of the study were: (1) to clarify the definitions of "migrant" used in occupational health research; (2) to summarize migrant workers' industry sectors, occupations and employment conditions; (3) to identify the occupational health and safety services available to migrant workers; (4) to summarize work-related health problems found among migrant workers; (5) to identify the methodological challenges to research into occupational health of migrant workers; and (6) to recommend improvements in migrant occupational health research. METHODS: This position paper was prepared by researchers from several European countries and Australia, working within the EU COST Action OMEGA-NET. The paper drew on two recent systematic reviews on the occupational health of international migrant workers and other literature, and also identified uncertainties and gaps in the research literature. Migrants may, for example, be temporary or permanent, moving for specific jobs migrants or other reasons. Their ethnicity and language capabilities will affect their work opportunities. RESULTS: The occupational health literature seldom adequately identifies the heterogeneity or characteristics of the migrant group being studied. Migrants tend to work in more physically and mentally demanding environments with higher exposures than native workers. Migrants tend to have an increased risk of physical and mental ill health, but less access to health care services. This has been demonstrated recently by high rates of COVID-19 and less access to health care. There have been a number of cross-sectional studies of migrant health but few long-term cohort studies were identified. Other study designs, such as registry-based studies, surveys and qualitative studies may complement cross-sectional studies. Mixed-methodology studies would be valuable in research on migrants' occupational health. Language and lack of trust are barriers to migrant research participation. CONCLUSION: Targeted research, especially longitudinal, identifying how these economically important but often-vulnerable workers can be best assisted is needed. Researchers should identify the characteristics of the migrant workers that they are studying including visa/migration circumstances (temporary, permanent, undocumented), racial and ethnic characteristics, existing skills and language abilities.

Quantitative levels of noise exposure and 20-year hearing decline: findings from a prospective cohort study (the HUNT Study).

OBJECTIVE: We aimed to assess the association between occupational noise exposure and long-term hearing decline. DESIGN: This prospective cohort study used linear regression to investigate the association between occupational noise exposure and 20-year hearing decline, adjusted for important confounders. STUDY SAMPLE: The Norwegian cohort (N = 4,448) participated in two population-based health studies with pure-tone audiometry; HUNT2 1996-1998 and HUNT4 2017-2019. Exposure assessments included a quantitative job exposure matrix (JEM) and questionnaires. RESULTS: The participants (40.2% men, 20-39 years at baseline) had a mean 20-year decline (3-6 kHz) of 11.3 ± 9.8 decibels (dB). There was a positive association between 20-year logarithmic average noise level (JEM-based, LEX,20y) and 20-year hearing decline among men. Compared with no exposure ≥80 dB during follow-up, minimum 5 years of exposure ≥85 dB (JEM-based) predicted 2.6 dB (95% CI: 0.2-5.0) larger 20-year decline for workers aged 30-39 years at baseline, and -0.2 dB (95% CI: -2.2 to 1.7) for workers aged 20-29 years. Combining JEM information with self-reported noise exposure data resulted in stronger associations. CONCLUSION: This large longitudinal study shows an association between JEM-based noise exposure level and increased 20-year hearing decline among men. Contrary to expectations, the associations were weaker among younger workers, which might reflect a latency period.

Occupational Noise Exposure and Vestibular Schwannoma: A Case-Control Study in Sweden.

It has been suggested that the association between self-reported occupational noise exposure and vestibular schwannoma (VS), found in several studies, represents recall bias. Therefore, we aimed to study the relationship in a large case-control study using occupational noise measurements. We performed a case-control study using data from Sweden for 1,913 VS cases diagnosed in 1961-2009 and 9,566 age- and sex-matched population controls. We defined occupational history by linkage to national censuses from 1960, 1970, 1980, and 1990. We estimated occupational noise exposure for each case and control using a job-exposure matrix. There was no association between occupational noise exposure and VS. Among subjects assessed as ever exposed to occupational noise levels of ≥85 dB (214 cases and 1,142 controls), the odds ratio for VS per 5 years of exposure was 1.02 (95% confidence interval: 0.90, 1.17). Workers with noise levels of ≥85 dB for at least 15 years (5-year latency period), showed no increased risk of VS (odds ratio = 0.98, 95% confidence interval: 0.73, 1.31) compared with those who had never been exposed to noise levels of 75 dB or higher. In summary, our large study does not support an association between occupational noise exposure and VS.

Landmark estimation of transition probabilities in non-Markov multi-state models with covariates.

In non-Markov multi-state models, the traditional Aalen-Johansen (AJ) estimator for state transition probabilities is generally not valid. An alternative, suggested by Putter and Spitioni, is to analyse a subsample of the full data, consisting of the individuals present in a specific state at a given landmark time-point. The AJ estimator of occupation probabilities is then applied to the landmark subsample. Exploiting the result by Datta and Satten, that the AJ estimator is consistent for state occupation probabilities even in non-Markov models given that censoring is independent of state occupancy and times of transition between states, the landmark Aalen-Johansen (LMAJ) estimator provides consistent estimates of transition probabilities. So far, this approach has only been studied for non-parametric estimation without covariates. In this paper, we show how semi-parametric regression models and inverse probability weights can be used in combination with the LMAJ estimator to perform covariate adjusted analyses. The methods are illustrated by a simulation study and an application to population-wide registry data on work, education and health-related absence in Norway. Results using the traditional AJ estimator and the LMAJ estimator are compared, and show large differences in estimated transition probabilities for highly non-Markov multi-state models.

Examination of work-related diseases among young people in Norway. / Utredning av unge med arbeidsrelatert sykdom.

BACKGROUND: The hospital departments for occupational medicine and the National Institute of Occupational Health (STAMI) established a shared, anonymous patient register in 2009. This report describes the diagnoses, occupations and exposure factors that occur most frequently in the youngest patient group. This will reflect exposures in modern working life in particular, and thus produce important knowledge with regard to targeted prevention efforts. MATERIAL AND METHOD: We have undertaken a descriptive analysis of 910 examinations of patients in the age group 20-29 years, performed in occupational medicine departments in Norway during the period 2010-17. RESULTS: Examinations of patients aged 20-29 years accounted for 914 (8 %) of a total of 11 969 recorded patient examinations. We excluded four participants for whom information on their sex was missing. This age group encompassed 498 (55 %) men, compared to 75 % men in the total dataset. The most frequent diagnoses were asthma (187/910, 21 %), contact eczema (184/910, 20 %) and rhinitis (73/910, 8 %). The most frequent exposure factors were irritants/allergens (469/910, 52 %). The most common occupations were hairdresser (159/910, 17 %) and painter/varnisher (46/910, 5 %). Hairdresser was the predominant occupation among women (154/412, 37 %), while painter/varnisher (35/498, 7 %) and electrician (25/498, 5 %) predominated among men. INTERPRETATION: Young patients who are examined in occupational medicine departments in Norway are most frequently registered with asthma or hand eczema. Hairdressers are especially exposed, indicating a special need for primary prevention in this occupation to prevent development of illness. In cases of asthma and hand eczema, doctors should be aware of the possibility that this might be occupationally related.

Occupational health examinations of patients in Norway. / Arbeidsmedisinsk pasientutredning i Norge.

BACKGROUND: In 2009, the hospital departments of occupational medicine and the National Institute of Occupational Health established a joint, anonymous examination register. The objective was to achieve a better overview of occupational health examinations of patients in Norway, including changes in occupationally related exposure and illness over time. MATERIAL AND METHOD: After the patient consultation the examining doctor completes a form, which is subsequently registered electronically. This article is based on analyses of patient examinations registered in the period 2010 ­ 2015. RESULTS: A total of 8 775 patient examinations had been recorded. The majority of those examined were men (75 %) and the most commonly occurring age group was 50 ­ 69 years (52 %). The most frequent exposures involved irritants/allergens (18 %) and organic solvents (15 %), which were recorded in a slightly increasing and slightly declining frequency respectively through the period. Manufacturing and mining were the top industries (30 %). The most common symptom organs were the lungs/respiratory tract (57 %), with asthma, COPD and lung cancer as the most frequent diagnoses. The proportion of cases that were deemed to be likely or possibly related to work remained stable at 40 % and 23 % respectively. At the time of the examination altogether 16 % of the patients were receiving sickness benefit, 10 % were receiving work assessment allowance and 13 % disability benefit. INTERPRETATION: Occupationally related illness entails significant consequences for individuals as well as society. The examination register provides a good overview of the patient examinations in the occupational health departments in Norway and may reveal changes in occupationally related exposure over time. In this way, the register may contribute to targeted preventive efforts.