Ascertainment of occupational histories in the working population: the occupational history calendar approach.

BACKGROUND: self-reported occupational histories are an important means for collecting historical data in epidemiological studies. An occupational history calendar (OHC) has been developed for use alongside a national occupational hazard surveillance tool. This study presents the systematic development of the OHC and compares work histories collected via this calendar to those collected via a traditional questionnaire. METHODS: the paper describes the systematic development of an OHC for use in the general working population. A comparison of data quality and recall was undertaken in 51 participants where both tools were administered. RESULTS: the OHC enhanced job recall compared with the traditional questionnaire. Good agreement in the data captured by both tools was observed, with the exception of hazard exposures. CONCLUSIONS: a calendar approach is suitable for collecting occupational histories from the general working population. Despite enhancing job recall the OHC approach has some shortcomings outweighing this advantage in large-scale population surveillance.

A prospective cohort study of health outcomes following whiplash associated disorders in an Australian population.

OBJECTIVE: To define health outcomes of whiplash associated disorders (WAD) at three months, six months, and two years after injury and to examine predictors of these outcomes. DESIGN: Prospective cohort study. SETTING: New South Wales, Australia. SUBJECTS: People with compensable motor crash injuries who reported whiplash as one of their injuries. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Functional Rating Index (FRI), Short Form 36 (SF-36) at three months, six months, and two years after injury, ascertained by telephone interview. RESULTS: At three months, 33.6% of the cohort was recovered (as defined by FRI

Comparison of fatalities from work related motor vehicle traffic incidents in Australia, New Zealand, and the United States.

OBJECTIVE: To compare the extent and characteristics of motor vehicle traffic incidents on public roads resulting in fatal occupational injuries in Australia, New Zealand (NZ), and the United States (US). DESIGN AND SETTING: Information came from separate data sources in Australia (1989--92), NZ (1985--98), and the US (1989--92). METHODS: Using data systems based on vital records, distributions and rates of fatal injuries resulting from motor vehicle traffic incidents were compared for the three countries. Common inclusion criteria and occupation and industry classifications were used to maximize comparability. RESULTS: Motor vehicle traffic incident related deaths accounted for 16% (NZ), 22% (US), and 31% (Australia) of all work related deaths during the years covered by the studies. Australia had a considerably higher crude rate (1.69 deaths/100,000 person years; 95% confidence interval (95% CI) 1.54 to 1.83) compared with both NZ (0.99; 95% CI 0.85 to 1.12) and the US (0.92; 95% CI 0.89 to 0.94). Industry distribution differences accounted for only a small proportion of this variation in rates. Case selection issues may have accounted for some of the remainder, particularly in NZ. In all three countries, male workers, older workers, and truck drivers were at higher risk. CONCLUSIONS: Motor vehicle traffic incidents are an important cause of work related death of workers in Australia, NZ, and the US. The absolute rates appear to differ between the three countries, but most of the incident characteristics were similar. Lack of detailed data and inconsistencies between the data sets limit the extent to which more in-depth comparisons could be made.

The impact of a nap opportunity during the night shift on the performance and alertness of 12-h shift workers.

The purpose of this workplace evaluation was to assess the effects on performance, alertness and subsequent sleep of strategic napping on 12-h overnight shifts. In a counterbalanced crossover design, 24 male aircraft maintenance engineers working in a forward rotating 12-h shift pattern volunteered to take part in the study for two work weeks. During the experimental week, each subject was given the opportunity to take a 20-min nap at work between 01:00 and 03:00 h on each of their two overnight shifts. On the control week no naps were taken on the night shifts. A computerized neurobehavioural test battery was employed to assess performance and subjective levels of fatigue at the beginning and end of each night shift, and pre- and postnap. Subjects were also asked to rate how near they had come to falling asleep while driving to and from work. The results revealed that taking a single 20-min nap during the first night shift significantly improved speed of response on a vigilance task measured at the end of the shift compared with the control condition. On the second night shift there was no effect of the nap on performance. Taking a short nap during either night shift had no significant effect on subjective ratings of fatigue, the level of sleepiness reported while driving to and from work, or subsequent sleep duration and sleep quality. Overall the results suggest some promise for a short duration nap taken in the workplace to counteract performance deficits associated with the first night shift.

Health of farmers in southland: an overview.

AIM: To describe the health of farmers in Southland. METHODS: Coss-sectional study of a random sample of farmers in Southland. RESULTS: 586 individuals were interviewed from 286 farms with a response rate of 65.4%. The prevalence of at least one injury in the last twelve months which prevented normal farm work was 17.1%. Low back pain was common with 54.6% reporting such an episode in the last twelve months. Noise-induced hearing loss was prevalent among men with 28.7% of those 45 years and over being affected. Levels of asthma appeared low with a point prevalence of 6.8%, with 4.6% on medication. There were 19.3% of male farmers who were obese. The prevalence of alcohol use disorder among men aged 15-24 years was 57.4%, and 39.0% among farm workers. Similarly, 32.0% of men in this age-group smoked, with 35.6% of farm workers being smokers. CONCLUSIONS: Farmers experienced high levels of injury, low back pain and noise-induced hearing loss. Community intervention programmes to prevent injury remain a priority for farmers, although lifestyle factors should also be addressed, particularly among farm workers.

Maori work-related fatal injury, 1985-1994.

AIMS: To document the rate of work-related fatal injury for Maori; to establish whether a difference exists between Maori and non-Maori; and to examine possible explanations in the event that differences did occur. METHODS: Coronial files collected as part of the examination of work-related fatal injuries occurring between 1985 and 1994, excluding motor vehicle fatalities on public roads, were reviewed. Maori were identified by either the classification recorded upon death certificates or if they were identified as Maori within coroner's files. RESULTS: 89 Maori were identified within the 741 worker fatalities. Agreement between the data sources used to identify ethnic status was approximately 52%. The crude rate for the decade was significantly higher for Maori than non-Maori. A significant linear decline across years was evident for the non-Maori rates but not for Maori rates. CONCLUSIONS: This study, the first to specifically investigate work-related injury for Maori, confirms that an overall disparity exists between Maori and non-Maori, and that it is probably due to differences in employment patterns.

Use of narrative analysis for comparisons of the causes of fatal accidents in three countries: New Zealand, Australia, and the United States.

OBJECTIVES: To investigate the utility of narrative analysis of text information for describing the mechanism of injury and to compare the patterns of the mechanism of injury for work related fatalities in three countries. METHODS: Three national collections of data on work related fatalities were used in this study including those for New Zealand, 1985-94 (n=723), for Australia, 1989-92 (n=1,220), and for the United States, 1989-92 (16,383). The New Zealand and Australian collections used the type of occurrence standard code for the mechanism of injury, however the United States collection did not. All three databases included a text description of the circumstances of the fatality so a text based analysis was developed to enable a comparison of the mechanisms of injury in each of the three countries. A test set of 200 cases from each country dataset was used to develop the narrative analysis and to allow comparison of the narrative and standard approaches to mechanism coding. RESULTS: The narrative coding was more useful for some types of injury than others. Differences in coding the narrative codes compared with the standard code were mainly due to lack of sensitivity in detecting cases for all three datasets, although specificity was always high. The pattern of causes was very similar between the two coding methods and between the countries. Hit by moving objects, falls, and rollovers were among the five most common mechanisms of workplace fatalities for all countries. More common mechanisms that distinguished the three countries were electrocutions for Australia, drowning for New Zealand, and gunshot for the United States. CONCLUSION: Narrative analysis shows some promise as an alternative approach for investigating the causes of fatalities.

Fatal work related injuries in agricultural production and services to agriculture sectors of New Zealand, 1985-94.

OBJECTIVES: To describe work related fatal injuries to agricultural workers in New Zealand to identify priority areas for further research and injury control measures. METHODS: Injury deaths in New Zealanders aged 15-84 inclusive for the period 1985-94 were identified and the coroner's files for these obtained. These files were then reviewed to determine whether the death arose as a result of work activities. Those deaths considered to be work related were coded for information relating to decedent demographics and the circumstances of the fatal injury. Work related deaths from injury occurring in the agricultural production and services to agriculture sectors were analysed. RESULTS: The rate of fatal injuries to male agricultural workers over the study period was 21.2/100 000, with injury deaths in the agricultural sectors accounting for nearly a quarter of all work related fatal injuries in New Zealand in that time. There was no significant decline in fatal injuries to agricultural workers in the study decade. Workers in the 65-84 age bracket were at substantially higher risk of fatal injury than other age groups. Machinery and motor vehicles were commonly associated with fatal injury, with overturns on or next to embankments and slopes being the most frequent scenario. CONCLUSIONS: The results of this study highlight fatal injuries in older workers and machinery incidents (particularly tractors overturning) as priority areas for further research into contributing factors and injury control measures.

Comparison of work related fatal injuries in the United States, Australia, and New Zealand: method and overall findings.

OBJECTIVES: To compare the extent, distribution, and nature of fatal occupational injury in New Zealand, Australia, and the United States. SETTING: Workplaces in New Zealand, Australia, and the United States. METHODS: Data collections based on vital records were used to compare overall rates and distribution of fatal injuries covering the period 1989-92 in Australia and the United States, and 1985-94 in New Zealand. Household labour force data (Australia and the United States) and census data (New Zealand) provided denominator data for calculation of rates. Case definition, case inclusion criteria, and classification of occupation and industry were harmonised across the three datasets. RESULTS: New Zealand had the highest average annual rate (4.9/100,000), Australia an intermediate rate (3.8/100,000), and the United States the lowest rate (3.2/ 100,000) of fatal occupational injury. Much of the difference between countries was accounted for by differences in industry distribution. In each country, male workers, older workers, and those working in agriculture, forestry and fishing, in mining and in construction, were consistently at higher risk. Intentional fatal injury was more common in the United States, being rare in both Australia and New Zealand. This difference is likely to be reflected in the more common incidence of work related fatal injuries for sales workers in the United States compared with Australia and New Zealand. CONCLUSIONS: The present results contrasted with those obtained by a recent study that used published omnibus statistics, both in terms of absolute rates and relative ranking of the three countries. Such differences underscore the importance of using like datasets for international comparisons. The consistency of high risk areas across comparable data from comparable nations provides clear targets for further attention. At this stage, however, it is unclear whether the same specific occupations and/or hazards are contributing to the aggregated industry and occupation group rates reported here.

Developing measures of fatigue using an alcohol comparison to validate the effects of fatigue on performance.

The effects of 28 h of sleep deprivation were compared with varying doses of alcohol up to 0.1% blood alcohol concentration (BAC) in the same subjects. The study was conducted in the laboratory. Twenty long-haul truck drivers and 19 people not employed as professional drivers acted as subjects. Tests were selected that were likely to be affected by fatigue, including simple reaction time, unstable tracking, dual task, Mackworth clock vigilance test, symbol digit coding, visual search, sequential spatial memory and logical reasoning. While performance effects were seen due to alcohol for all tests, sleep deprivation affected performance on most tests, but had no effect on performance on the visual search and logical reasoning tests. Some tests showed evidence of a circadian rhythm effect on performance, in particular, simple reaction time, dual task, Mackworth clock vigilance, and symbol digit coding, but only for response speed and not response accuracy. Drivers were slower but more accurate than controls on the symbol digit test, suggesting that they took a more conservative approach to performance of this test. This study demonstrated which tests are most sensitive to sleep deprivation and fatigue. The study therefore has established a set of tests that can be used in evaluations of fatigue and fatigue countermeasures.

The work-related fatal injury study: numbers, rates and trends of work-related fatal injuries in New Zealand 1985-1994.

AIMS: To determine the number and rates of work-related fatal injuries by employment status, occupation, industry, age and gender in New Zealand 1985-1994. METHODS: Potential cases of work-related injury deaths of persons aged 15-84 years were identified from the national electronic mortality data files. Main exclusions were deaths due to suicide and deaths due to motor vehicle crashes. The circumstances of the deaths of each fatal incident meeting inclusion criteria were then reviewed directly from coronial files to determine work-relatedness. RESULTS: The rate of work-related fatal injury in New Zealand was 5.03/100000 workers per year for the study period. There was a significant decline in crude rate over the study period. However, this was in substantial part accounted for by changes in occupation and industry mix. Older workers, male workers, self-employed workers, and particular occupational groups, all had substantially elevated rates. Agricultural and helicopter pilots, forestry workers and fishery workers had the highest rates. Farmers, forestry workers, and fishery workers also had high numbers of deaths, together accounting for nearly 40% of all deaths. CONCLUSIONS: This study has demonstrated that work-related fatal injury remains a pressing problem for New Zealand. Several areas in urgent need of prevention efforts were highlighted.

Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication.

OBJECTIVES: To compare the relative effects on performance of sleep deprivation and alcohol. METHODS: Performance effects were studied in the same subjects over a period of 28 hours of sleep deprivation and after measured doses of alcohol up to about 0.1% blood alcohol concentration (BAC). There were 39 subjects, 30 employees from the transport industry and nine from the army. RESULTS: After 17-19 hours without sleep, corresponding to 2230 and 0100, performance on some tests was equivalent or worse than that at a BAC of 0.05%. Response speeds were up to 50% slower for some tests and accuracy measures were significantly poorer than at this level of alcohol. After longer periods without sleep, performance reached levels equivalent to the maximum alcohol dose given to subjects (BAC of 0. 1%). CONCLUSIONS: These findings reinforce the evidence that the fatigue of sleep deprivation is an important factor likely to compromise performance of speed and accuracy of the kind needed for safety on the road and in other industrial settings.

The role of physical and psychological factors in occupational low back pain: a prospective cohort study.

OBJECTIVE: To examine risk factors for onset of low back pain (LBP) in healthcare workers. METHODS: Nursing students, during their 3 year training period, and 1 year after training were studied in a prospective cohort study, with repeated self reported measurements of determinants of LBP at 6 monthly intervals for 3 years during training, and after a 12 month interval there was an additional final follow up. RESULTS: During training, increased risk of new episodes of LBP was associated with having had LBP at baseline, with part time work, and with a high score on the general health questionnaire (GHQ). A high GHQ score preceded the onset of LBP, in such a way that a high score at the immediately previous follow up increased risk of LBP at the next follow up. 12 Months after training, a history of recurring LBP during training increased the risk of a new episode as did having obtained work as a nurse. A high GHQ score at this follow up was also associated with a concurrently increased risk. Pre-existing GHQ score, either at the end of training or at baseline, had no effect on risk of LBP 12 months after training. CONCLUSIONS: Other than a history of LBP, pre-existing psychological distress was the only factor found to have a pre-existing influence on new episodes of LBP. Increased levels of psychological distress (as measured by the GHQ) preceded the occurrence of new episodes of pain by only short intervening periods, implying a role for acute distress in the onset of the disorder. This finding suggests that management of the onset of occupational LBP may be improved by management of psychological distress.

Hours of work, and perceptions of fatigue among truck drivers.

Drivers and companies operating in the heavy road transport industry were surveyed about drivers' hours of work and perceptions of the causes and magnitude of fatigue as an industry problem. These drivers were operating in a state which, at the time of the survey, did not restrict driving hours for heavy haulage drivers. On the day of the interview, estimates based on retrospective and prospective reports, suggest that in a 24 hour period about 38% of drivers exceed 14 hours of driving, and 51% exceed 14 hours of driving plus other non-driving work. About 12% of drivers reported less than 4 hours of sleep on one or more working days in the week preceding the interview. These drivers are likely to be operating their vehicles while having a significant sleep debt. About 20% of drivers reported less than 6 hours sleep before starting their current journey, but nearly 40% of dangerous events that occurred on the journey were reported by these drivers (p < 0.05). Many drivers and company representatives reported fatigue to be a problem for other drivers, but considered themselves or their companies' drivers to be relatively unaffected by fatigue. There were differences between drivers' and companies' perceptions about causes of fatigue, and strategies that should be used to manage it. The results obtained from these drivers in an unregulated state were compared with earlier findings from drivers in states where driving hours restrictions are in place.

Balancing work and rest to combat driver fatigue: an investigation of two-up driving in Australia.

This study is the fourth in a series examining driver fatigue in the Australian long distance road transport industry. Thirty-seven long haul truck drivers were measured on a routine 4500 km round trip. Two types of driving operations were compared, single driving, involving a solo driver, and two-up driving, where a pair of drivers operate a truck continuously and alternate between work and rest. Two-up drivers reported higher levels of fatigue than single drivers overall and tended to show poorer levels of performance. However, this result appeared to reflect differential fatigue at the start of the trip. Both two-up and single drivers showed marked increases in fatigue across the first half of the trip, followed by a substantial recovery of alertness and performance provided that drivers had stationary overnight rest at mid trip or had shorter trips. Fatigue continued to increase on the second half of the trip for drivers who did longer trips without the benefit of a substantial night rest or who did not have access to on-board rest, that is single drivers. The use of overnight rest, in combination with two-up driving, appeared to be the most successful strategy for managing fatigue across the trip.

The impact of work practices on fatigue in long distance truck drivers.

Twenty seven professional truck drivers completed a 12 hour, 900 km trip under each of three driving regimes-a relay (staged) trip, a working hours regulated one-way (single) trip, and a one-way (flexible) trip with no working hours constraints. The results indicated that none of the driving regimes prevented fatigue and that the pattern of fatigue experienced during the trips appeared to be related to pretrip fatigue levels.

Role of psychosocial risk factors in work-related low-back pain.

The experience of low-back pain and its psychosocial associates were directly compared among sufferers drawn from three populations, a blue-collar working group, a white-collar working group, and a patient group. Sufferers drawn from the patient population revealed the expected psychological disturbance. There was no evidence of such involvement for sufferers still at work. Disability resulting from low-back pain was positively linearly related to severity of pain for sufferers drawn from working groups, irrespective of psychological disturbance. For patients, on the other hand, the presence of psychological disturbance modified the relationship between severity and disability such that no simple linear relationship existed between the two variables. Work dissatisfaction was not found to be related to the presence of, and did not account for disability resulting from, low-back pain in working subjects.

A classification system for causes of occupational accidents for use in preventive strategies.

A comprehensive classification system, which allowed operational analysis of the events preceding accidents, was applied to the analysis of information surrounding the occurrence of all traumatic work-related fatalities in Australia in 1982-1984. The coded information included factors immediately antecedent to the accident leading to the fatality and factors removed in time which contributed to the occurrence of the accident. The complex network of events leading up to the accident, their interrelationships, and their relative contribution to causing the accident were examined. The results provide information about the use of accident analysis for the formulation of preventive strategies.