Tomas Backström

Typical accidents encountered by assembly workers: six scenarios for safety planning identified using multivariate methods

This study highlights the most typical accidents encountered by assembly workers employed in a variety of different workshops at a large automobile and truck factory in Sweden. Following site visits and the collection of data from accident registers, statistics on 28 accident characteristics were compiled on the basis of the 145 accidents involving assemblers in 1986 and 1987. For data treatment, two statistical methods complemented one another: the factorial analysis of correspondence (FAC) and the hierarchical ascendant classification (HAC). Six typical accident profiles were extensively portrayed, quantified, and illustrated graphically: overexertion; falls and stumbling; injuries related to the handling of tools; superficial wounds to the (left) hand; cuts/pinches from moving machine parts and the handling of objects; miscellaneous blows from work pieces. The distribution of these types of accidents across the workshops was studied. It is emphasized that the search for typical accident patterns using multivariate statistical methods helps to structure and define the accident problems of a target group and therefore provides benefits for the evaluation of the need for preventive measures.

Identifying accident patterns using the FAC and HAC: their application to accidents at the engine workshops of an automobile and truck factory

Abstract This paper raises the issue of the optimum utilization of information from accident registers for the achievement of one main goal: the facilitation of safety planning. It proposes a non-traditional way of analyzing accident data that provides a condensed and comprehensive overview of the most common accident problems encountered by a target group. A description of typical accident patterns is obtained by the simultaneous treatment of the entire body of information compiled. Data analysis is performed on the basis of the following question: What are the most typical injury events and in terms of which factors may their characteristics be explained? Two statistical methods complement one another: the Factorial Analysis of Correspondence (FAC) and the Hierarchical Ascendant Classification (HAC). The target group comprised blue-collar workers at the engine workshops of a large automobile and truck factory in Sweden. As well as the identification and characterization of the main accident patterns, the study was also designed to estimate the risk of accidents for six occupational groups and to establish whether levels of risk were similar between workshops for each occupational group. Statistics on accident characteristics were compiled on the basis of the 178 accident declaration forms filled in during 1986 and 1987. These forms were filled in when an injured worker had been away from work at least one day after an accident. Data on a total of 35 variables were collected. These variables covered seven themes: (1) the time of the accident; (2) its location; (3) the injured worker; (4) the activity performed by the injured worker; (5) the machinery and/or tool involved, if any; (6) the accident event; (7) the injury. Seven typical accident classes (patterns) were extensively portrayed. It was observed that accidents of any class might occur in either workshop, but that their distribution varies according to the occupational group, and the tasks performed by the injured workers. It was also shown that accident frequency varies considerably from one occupational group to another; and for some groups, from workshop to workshop. It is emphasized that the multivariate analysis of the data available in accident registers both broadens and enriches understanding of the accident problems encountered by a target group. It also represents an important supplement to traditional accident statistics. This non-traditional way of defining accident problems may, through the treatment of one accident pattern (class) at a time, provide assistance in understanding and evaluating the need for preventive measures. Further accident prevention and, in a broader sense, safety improvements, may be made considerably easier on the basis of the type of reference material obtained.

Immigrants and occupational accidents: A comparative study of the frequency and types of accidents encountered by foreign and Swedish citizens at an engineering plant in Sweden

Abstract The study concerns the relationship between citizenship and accidents, broken down by workshop, occupational group, age and experience, at a Swedish automobile and truck factory. It covers 537 accidents among personnel employed under collective agreement over the years 1986–1987. Comparisons between average annual frequency rates for Swedish and foreign citizens are made. The study offers no support for the view that immigrants are at greater risk than nationals for occupational accidents. In fact, most of the comparisons showed a higher accident frequency among workers of Swedish nationality, although statistically significant differences between groups were obtained in only a few cases. There was, however, a higher accident frequency for young and less experienced foreign citizens than for young Swedish nationals. In an analysis of the 178 accidents that occurred at the companys engine workshops, attention was also paid to the relationships between type of accident situation on the one hand and citizenship and country of birth on the other. These shops had a high proportion of immigrants and a relatively high accident frequency. A multivariate method of analysis was employed, involving the application of cross-tabulations and Chi-square tests to previously factored/clustered data. No significant difference between foreign and Swedish citizens emerged with respect to type of accident situation. This study does not indicate that there is a need for immigrants as a group to be specifically targeted in work designed to prevent occupational accidents.

Evaluation of a strategy. Preventing accidents with automated machinery through targeted and comprehensive investigations conducted by safety engineers

Abstract This article addresses the question of the usefulness of a strategy of comprehensive, targeted accident investigations. The strategy has been tested at fifteen manufacturing companies where the accidents that occurred in automated production were investigated using a purpose-built investigation chart. The investigators were principally safety engineers. The strategy has been evaluated through retrospective interviewing of 18 accident investigators and by examining the number of accidents at the participating companies. The strategy has been of considerable benefit for seven of the investigators, while the others benefited to a lesser and varying extent. It was mainly those who carried out more than five investigations who obtained the greatest benefit. Above all the investigatory work was reported to have contributed to learning about the causes of and factors involved in accidents at automated installations. To determine whether the strategy contributed to a fall in the number of accidents is not possible on the basis of our data. The investigators also considered this hard to assess. Nevertheless, in a randomly-selected sample of accidents at the companies involved in the project, “automation accidents” as a proportion of all occupational accidents had in fact fallen by the end of the investigation period (in comparison with the start of the investigatory activities). The main conclusions that can be drawn are that the interview with the injured person has provided the investigators with new knowledge (on, for example, accident risks involved in automated production, job routines and the machinery), and that the strategy has been most successful at companies where the investigator has actively applied his new knowledge and disseminated it to others.