Anne-Marie Feyer

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.

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.

Behavioural epidemiology as a tool for accident research

Abstract Williamson, A. and Feyer, A.-M., 1990. Behavioural epidemiology as a tool for accident research. Journal of Occupational Accidents , 12: 207–222. In this study the incidence and nature of behavioural events preceding work-related fatalities were investigated. All occupational facilities were examined for the years 1982 to 1984. The events preceding the fatality and any pre-existing factors that contributed to the fatality were coded. The coding focussed on such aspects as the environment, equipment design and upkeep, as well as human factors like work practice, supervision, training, medical precursors and task errors. The primary events and contributory factors were ranked and weighted in order to establish the casual relationships between them. Multivariate analysis was used to determine the nature of these relationships across all fatalities. As this study covers so many types of accidents in such a wide variety of occupational groups, the results provide more specific information about human behavioural epidemiological method to evaluate the impact of different aspects of human error on accident causation. This method will allow highlighting of the most suitable strategies for accident prevention.

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=1220), 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.

Industry differences in accident causation

Abstract Occupational fatalities are thought to have similar origins across different types of work. In this study all occupational fatalities occurring in Australia over a three year period were coded and classified using a method designed to describe the comprehensive causes of accidents. The aim of the study was to determine whether there are general causation patterns for fatalities at work across all industry. One thousand and twenty occupational fatalities were coded for the analysis. Correspondence analysis and cluster analysis were used to describe the patterns and relationships between occupational groups and nature of the accident precursor sequence. The results of the final cluster analysis showed that fatalities occurred in a similar manner for most occupational groups. The major exceptions were timbergetters and electrical trades workers. Two main factors seemed to be important, however, in distinguishing the nature of accident precursors of the occupational groups — the gross nature of the accident sequence with respect to the involvement of behavioural or environmental factors and the presence or absence of unsafe work practices as contributors to the sequences. There was some interaction between these two factors.

Musculoskeletal discomfort and work-related stress in New Zealand dentists

Abstract There has been little research into the stressors, psychological distress and musculoskeletal symptoms experienced by dentists. The present study was carried out among a random sample of New Zealand dentists (N=413). The present study aimed to identify the severity of work psychosocial stressors, examine the occurrence of musculoskeletal discomfort and psychological disturbance, and determine relationships between these factors. The average age of the dentists was 43 years, with 74% being male. The annual prevalence of symptoms in both the lower back or neck was 63%, with 49% experiencing symptoms in the shoulders. Older dentists were no more likely to suffer musculoskeletal discomfort than younger dentists. The highest ranking dentistry-specific work-related stressor was ‘patients having a medical emergency’ with 78% scoring this stressor very highly. Dentists scored mental demands as the highest general work-related stressor. One-fifth of the dentists scored highly for psychological disturbance, which was very similar to the general population. Dentists with high scores for dentistry-specific work-related stressors were more likely to have evidence of psychological disturbance. The relationships between psychological disturbance and musculoskeletal discomfort needs to be taken into account when considering any multidisciplinary approach to prevention.

The involvement of human behaviour in occupational accidents: Errors in context

The information surrounding the occurrence of all traumatic work-related fatalities in Australia over the years 1982 to 1984 was analyzed. Previous analysis of patterns of accident causation revealed that pre-existing poor work practices were the most common precursors of human errors precipitating fatalities, and that, overall, this combination of causal factors was the most common one leading to fatalities. The present paper examined further the nature of work practices involved in these fatalities and their relationship to subsequent behavioural events in the accident sequence. The most common work practices were those associated with procedures, either originating from management or individual practices. Examination of the association of particular work practices with the occurrence of subsequent human errors revealed that the origin of the unsafe practice varied for different error types. Individual worker practices, safety equipment and personal protective equipment practices were all associated with later skill-based errors. In contrast, management practices were associated with knowledge-based errors, while general equipment practices were associated with rule-based errors. These findings provide evidence for the view that aspects of work organization provide the circumstances in which later events may precipitate the accident. Moreover, the data suggest that being able to identify the precursors of critical events, and, in particular, those events that are difficult to directly target, can provide a specific focus for prevention. Knowledge-based errors can be directly targeted for prevention, whereas for skill-based errors the only avenue for prevention lies in targeting the surrounding circumstances.

Work and rest in the long-distance road transport industry in Australia

Abstract To date management of fatigue in professional drivers has largely focused on strategies that limit the amount of time spent on the job. These approaches have, however, not taken into account the well-documented effect of time of day. Consequently, the likely impact of the pattern and timing of work and rest has received little attention. The results revealed that the group of drivers who did the shortest trips and worked the shortest weekly hours were the lowest reporters of fatigue, although longer hours were not always associated with the highest reporting of fatigue. In contrast, the shortest working hours were associated with earliest onset of fatigue. For all drivers, the influence of circadian rhythms was evident in the occurrence of fatigue, with better management of the problem evident among drivers who were able to arrange the timing of rest to more closely coincide with periods of fatigue. Thus, time of day appeared to be a more important influence in determining effective rest than did...

Causes of accidents and the time of day

Abstract The relationship between accidents and the time of day is not entirely clear. Although there is considerable evidence that performance is poorest in the early morning hours compared to at all other times, the degree to which this is translated into accidents is not understood. In this study work-related fatal accidents were analysed to determine whether the causes of these accidents vary with time. The analysis used a classification and coding system devised to describe the wider circumstances of the causes of fatalities. In terms of absolute numbers, fatalities were most common in the late morning or early afternoon. When these results were expressed in terms of the estimated number of workers at work, the proportion of fatal accidents occurring at night was more than double that occurring during the day. Behavioural factors were the most common cause of fatalities at all times, but most common in the early hours of the morning. Further analysis of the nature of the behavioural involvement showe...

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.