Arve Lie

Work-related post-traumatic stress disorder

BACKGROUND Work-related post-traumatic stress disorder (PTSD) is an important condition encountered by many occupational health practitioners. AIMS To carry out an in-depth review of the research on occupational groups that are at particular risk of developing work-related PTSD. METHODS A literature search was conducted in the databases OVID MEDLINE, OVID Embase, Ovid PsycINFO, ISI Web of Science and CSA Health and Safety Science Abstracts. RESULTS Professionals such as police officers, firefighters and ambulance personnel often experience incidents that satisfy the stressor criterion for the PTSD diagnosis. Other professional groups such as health care professionals, train drivers, divers, journalists, sailors and employees in bank, post offices or in stores may also be subjected to work-related traumatic events. Work-related PTSD usually diminishes with time. CONCLUSIONS Mental health problems prior to the traumatic event and weak social support increase the risk of PTSD. Prevention of work-related PTSD includes a sound organizational and psychosocial work environment, systematic training of employees, social support from colleagues and managers and a proper follow-up of employees after a critical event.

Systematic review of the cardiovascular effects of occupational noise

BACKGROUND Cross-sectional studies of occupational noise and cardiovascular effects show an association between noise and hypertension but for coronary heart disease or other cardiovascular diseases (CVDs) the evidence is not convincing. AIMS To assess possible associations between occupational noise exposure and the risk for cardiovascular effects in follow-up studies published after 1999. METHODS We performed a systematic critical literature review of original articles from key literature databases of associations between workplace noise and health. The studies were identified by search in Ovid Medline, Ovid Embase, Web of Science, Scopus and ProQuest Health and Safety Sciences Abstracts. We selected prospective studies of adequate quality with a measure of association between occupational noise exposure and cardiovascular health for the meta-analysis. RESULTS Twelve papers, all prospective and mostly with high quality but with methodological shortcomings in exposure assessment, were included in the review and meta-analysis. Exposure to noise at work was consistently positively associated with hypertension [Hazard ratio (HR) = 1.68; 95% confidence interval (CI) 1.10-2.57] and CVD [relative risk (RR) = 1.34; 95% CI 1.15-1.56]. In addition, we found a trivial effect of noise exposure on CVD mortality (HR = 1.12; 95% CI 1.02-1.24). CONCLUSIONS Occupational noise exposure is strongly associated with hypertension. For other cardiovascular effects, this meta-analysis suggests a weak association, but the evidence is limited. More longitudinal studies on the effects of occupational noise on the cardiovascular system are warranted.

Hearing status among Norwegian train drivers and train conductors

Background There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss. Aims To study job-related hearing loss among train drivers and train conductors. Methods Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an external reference group of people not occupationally exposed to noise. The monaural hearing threshold level at 4kHz, the mean binaural value at 3, 4 and 6kHz and the prevalence of audiometric notches (≥25 dB at 4kHz) were used for comparison. Results Audiograms were available for 1567 drivers, 1565 conductors, 4029 railway worker controls and 15 012 people not occupationally exposed to noise. No difference in hearing level or prevalence of audiometric notches was found between study groups after adjusting for age and gender. Conclusions Norwegian train drivers and conductors have normal hearing threshold levels comparable with those in non-exposed groups.

Cardiovascular risk factors and hearing loss: The HUNT study

Abstract Objective: The purpose of the present paper was to examine the association between prospectively and cross-sectionally assessed cardiovascular risk factors and hearing loss. Design: Hearing was assessed by pure-tone average thresholds at low (0.25–0.5 kHz), middle (1–2 kHz), and high (3–8 kHz) frequencies. Self-reported or measured cardiovascular risk factors were assessed both 11 years before and simultaneously with the audiometric assessment. Cardiovascular risk factors were smoking, alcohol use, physical inactivity, waist circumference, body mass index, resting heart rate, blood pressure, triglycerides, total serum cholesterol, LDL cholesterol, HDL cholesterol, and diabetes. Study sample: A population-based cohort of 31 547 subjects. Results: After adjustment for age, sex, level of education, income, recurrent ear infections, and noise exposure, risk factors associated with poorer hearing sensitivity were smoking, diabetes, physical inactivity, resting heart rate, and waist circumference. Smoking was only associated with hearing loss at high frequencies. The effects were very small, in combination explaining only 0.2–0.4% of the variance in addition to the component explained by age and the other cofactors. Conclusion: This cohort study indicates that, although many cardiovascular risk factors are associated with hearing loss, the effects are small and of doubtful clinical relevance.

A cross-sectional study of hearing thresholds among 4627 Norwegian train and track maintenance workers

Objective Railway workers performing maintenance work of trains and tracks could be at risk of developing noise-induced hearing loss, since they are exposed to noise levels of 75–90 dB(A) with peak exposures of 130–140 dB(C). The objective was to make a risk assessment by comparing the hearing thresholds among train and track maintenance workers with a reference group not exposed to noise and reference values from the ISO 1999. Design Cross-sectional. Setting A major Norwegian railway company. Participants 1897 and 2730 male train and track maintenance workers, respectively, all exposed to noise, and 2872 male railway traffic controllers and office workers not exposed to noise. Outcome measures The primary outcome was the hearing threshold (pure tone audiometry, frequencies from 0.5 to 8 kHz), and the secondary outcome was the prevalence of audiometric notches (Coles notch) of the most recent audiogram. Results Train and track maintenance workers aged 45 years or older had a small mean hearing loss in the 3–6 kHz area of 3–5 dB. The hearing loss was less among workers younger than 45 years. Audiometric notches were slightly more prevalent among the noise exposed (59–64%) group compared with controls (49%) for all age groups. They may therefore be a sensitive measure in disclosing an early hearing loss at a group level. Conclusions Train and track maintenance workers aged 45 years or older, on average, have a slightly greater hearing loss and more audiometric notches compared with reference groups not exposed to noise. Younger (<45 years) workers have hearing thresholds comparable to the controls.

The prevalence of notched audiograms in a cross-sectional study of 12,055 railway workers.

Objective: Noise-induced hearing loss (NIHL) is one of the most reported occupational diseases internationally. The occurrence of audiometric notches is emphasized in both American and European guidelines for the diagnosis of NIHL. The aim of this study was to describe the prevalence of notched audiograms among railway personnel with and without noise exposure to better assess the usefulness of such notches in the diagnosis of NIHL. Design: The most recent audiogram from 1994 to 2011 of a total of 12,055 railway workers, age 20 to 65 years, was obtained from the medical records of the occupational health service of the Norwegian State Railways (NSB). The prevalences of three types of notched audiograms, Coles notch, notch index, and 4 kHz notch, were computed, in relation to age, sex, and occupational noise exposure. Results: Coles notch in either ear was found in 63% of the male railway maintenance workers, exposed to noise levels of 75 to 90 dB(A), compared with 53% of the non-noise exposed (<70 dB(A)) traffic controllers (p < 0.001). The corresponding figures for the 4 kHz notch were 31% versus 21% (p < 0.001). For the notch index, 61% of the exposed and 51% of the controls had a notched audiogram (p < 0.001). For female workers, the prevalence of audiometric notches was lower, and the differences between noise exposed and nonexposed was smaller than those in men. Increasing age led to an increased prevalence of notches. Conclusions: Audiometric notches commonly occur among both noise-exposed and those not exposed to noise in railway personnel. The usefulness of audiometric notches in the diagnosis of NIHL is therefore limited.

Occupational noise exposure, hearing loss, and notched audiograms in the HUNT Nord‐Trøndelag hearing loss study, 1996–1998

To study the prevalence and usefulness of audiometric notches in the diagnosis of noise‐induced hearing loss (NIHL).

Noise-induced hearing loss in a longitudinal study of Norwegian railway workers

Objective The aim of this study was to analyse longitudinal data to assess the risk of noise-induced hearing loss (NIHL) in Norwegian railway workers. Design Longitudinal. Setting A major Norwegian railway company. Methods We examined data from the first and last audiograms for the period 1991–2014, from 9640 railway workers with varying occupational noise exposure and with an average observation period of 10 years. The course of hearing acuity in seven groups of railway workers (train drivers, conductors, bus drivers, traffic controllers, train maintenance workers, track maintenance workers and others) were compared with each other and with ISO standards (ISO 1999). Results The change in hearing threshold during the observation period was 2–3 dB in the 0.5–4 kHz range and 6–7 dB in the 3–6 kHz range adjusted for age and sex, for all occupational groups, which is slightly less than expected (8 dB) according to ISO 1999. Conclusions The risk of NIHL in Norwegian railway workers during the period 1991–2014 has been negligible.

Occupational Health Services in Norway – Legislative Framework, Trends, Developments and Future Perspectives

Introduction The history of occupational health (OH) services in Norway goes back to company physicians in the silver mining industry in Kongsberg during the 17th century. The first modern OH service unit is usually regarded as having been founded at the Freia Chocolate Company in Oslo in 1917 by Professor Schiøtz. A public health approach, based on prevention by hygienic inspections and health surveillance, was adopted. It was not until 1977, when the Work Environment Act was passed, that there was a major expansion of OH services, starting in particular with the emergence of external, multidisciplinary units providing services to many enterprises.

Accreditation of occupational health services in Norway.

Background In 2010, an accreditation system for occupational health services (OHS) in Norway was implemented. Aims To examine OHS experiences of the accreditation system in Norway 4 years after its implementation. Methods A web-based questionnaire was sent to all accredited OHS asking about their experiences with the accreditation system. Responses were compared with a similar survey conducted in 2011. Results The response rate was 76% (173/228). OHS reported that the most common changes they had had to make to achieve accreditation were: improvement of their quality assurance system (53%), a plan for competence development (44%) and increased staffing in occupational hygiene (36%) and occupational medicine (28%). The OHS attributed improved quality in their own OHS (56%) and in OHS in Norway (47%), to the accreditation process. Conclusions The accreditation system was well accepted by OHS, who reported that it had improved the quality of their OHS and of OHS in Norway. The results are similar to the findings of a 2011 survey.