Unintentional Machinery Injury on Farms in Victoria

Monash University Accident Research Centre - Report #148 - 1999

Authors: L. Day & A. McGrath

Full report in .pdf format [360KB]

Abstract:

Aim: We report the distribution of, and characteristics associated with, unintentional machinery injury on farms in Victoria to identify research issues and potential intervention strategies.

Method: Machinery was defined as items classifiable to the external cause of injury code E919 from the International Classification of Diseases Ninth Revision Clinical Modification, which includes agricultural, earth drilling, lifting, woodworking and earth moving machinery. The descriptive epidemiology of farm machinery injury was determined by analysis of four databases covering deaths, hospital admissions and emergency department presentations. Events preceding farm machinery injury, and factors associated with it, were examined in a retrospective case series of 19 adults with injuries meeting the study definition who presented with a machinery injury from 1996-1997 to the emergency department of four Victorian regional hospitals.

Results: There were an average annual of 1 child death, 6 adult work related deaths, 80 hospital admissions and 210 estimated emergency department presentations for machinery injury on farms. The tractor was the most common item of machinery involved, accounting for 100% of the child deaths, 71% of the adult work related deaths, and an estimated 71% of hospital admissions. Males were more frequently killed and injured than females. Passengers accounted for four of the five child tractor deaths. Roll overs and run overs accounted for 57% and 17% respectively of the adult work related tractor deaths, with the relative contribution shifting towards run overs in the last five years of data. The most common non-fatal injuries included bruising and crushing injuries, fractures, lacerations, and sprains, and the most common body parts injured were the hands and fingers. Among those who were hospitalised, 35% and 37% of children and adults respectively remained in hospital for more than 2 days.

Most of the case series participants (14) nominated their primary occupation as farming. Neither the weather nor the age of the machinery appeared to be implicated. Lack of sleep was not commonly reported by the case series participants. However, 8 out of the 19 reported to be working more than 40 hours per week, and 8 had a secondary occupation Without comparative data, it is difficult to implicate any of the other factors explored in this study.

Implications for prevention and further research: Almost all machinery related deaths among children on farms in this study could have been prevented by not carrying children as passengers on tractors. Given the programs currently addressing tractor roll over events in Victoria, a future challenge in preventing machinery related deaths on farms will be reducing the risk of run-over events. The prevention of machinery injury and deaths on farms would be greatly facilitated by studies that investigate in detail the circumstances leading up to the event, and the machinery involved, among a substantial number of cases. Such studies would determine the relative potential for prevention by either design solutions or work practice modification. The individual and environmental factors should also be investigated and compared with an appropriately selected group of non-injured control farmers, providing quantitative data to the farming community for the purposes of risk identification and management, further identifying high risk groups for prevention programs.

Executive Summary

Introduction

Farmers, farm workers and farm families are a high risk injury group. Overall patterns and leading causes of farm injury mortality and morbidity in Australia have been described, despite limitations with data availability and reliability (Fragar and Coleman, 1996). Machinery is a leading cause of fatal and serious farm injury (Harrison et al., 1989; Clarke and Coleman, 1995). This study was undertaken to quantify and describe the extent of machinery injury on farms in Victoria. A particular aim was to identify the types of non-tractor machinery associated with fatal and non-fatal injuries. Analyses of the available databases were conducted to provide an overview of the nature of farm machinery injury. In addition, a case series study of non-fatal farm machinery trauma incidents was undertaken to explore the circumstances of, and factors associated with these incidents.

Methods

Machinery injury on farms was defined as unintentional injury, occurring on a farm, caused by exposure to rapid transfer of mechanical, chemical, electrical, or thermal energy from an item(s) of machinery. "Machinery" includes items classifiable to the external cause of injury code (E-code) E919 from the International Classification of Diseases Ninth Revision Clinical Modification (ICD-9-CM). This includes agricultural, earth drilling, lifting, woodworking and earth moving machinery. Powered and un-powered hand tools were not included.

The descriptive epidemiology of farm machinery injury was obtained by the analysis of four databases covering all child injury deaths, all adult work place deaths, all hospital admissions for injury, and a considerable proportion of emergency department presentations in Victoria.

A retrospective case series study was also conducted. Cases were defined as adults (over 18 years of age) with injuries meeting the study definition who presented for treatment from 1996-1997 to the emergency department of four Victorian regional hospitals: Wimmera Base Hospital, Ballarat Base Hospital, Goulburn Valley Base Hospital, and Warrnambool and District Base Hospital. Presentations meeting the study definition for the E-code were selected from the Victorian Emergency Minimum Database. After obtaining ethics approval from Monash University and the 4 hospitals, potential respondents were invited to participate by either letter or telephone. Telephone interviewing by a research nurse was conducted using a questionnaire to gather demographic, individual, machinery and farm characteristics, and information relating to the circumstances leading up to the injury.

Results

Database Analysis

There were an average annual of 1 child death, 6 adult work related deaths, 80 hospital admissions and 210 estimated emergency department presentations for machinery injury on farms. The tractor was the most common item of machinery involved, accounting for 100% of the child deaths, 71% of the adult work related deaths, and an estimated 71% of hospital admissions. Males were more frequently killed and injured than females. Passengers accounted for four of the five child tractor deaths. Roll overs and run overs accounted for 57% and 17% respectively of the adult work related tractor deaths, with the relative contribution shifting towards run overs in the most recent five years of data (43% and 25% respectively).

The most common non-fatal injuries included bruising and crushing injuries (40%), and fractures (38%) among those admitted to hospital, and lacerations (25%) and sprains (20%) among emergency department presentations. The most common body parts injured included the hands and fingers, accounting for 31% and 34% of hospital admissions and emergency department presentations respectively. Among those who were hospitalised, 35% and 37% of children and adults respectively remained in hospital for more than 2 days.

Case Series

The overall response rate for the case series was 47%. Of the 31 non-respondents, 22 declined to participate and 9 had initially agreed but could not be re-contacted. The non-respondents tended to be younger and have less severe injuries than the respondents. Although selected from the data base according to external cause of injury code for machinery, nine respondents were injured by items which did not meet the ICD-9 definition selected for this study and were excluded. Therefore, 19 cases were available for analysis.

Fourteen respondents considered their primary occupation to be in the farming industry. An additional three were employed in the trucking industry. Eight respondents had a secondary occupation, seven of which were in the farming industry. All respondents were employed in the farming industry in either the primary or secondary occupation. Eleven respondents were the farm owner. Seventeen respondents had at least 10 years experience in farming, 11 of whom had more than 20 years experience.

All respondents were working at the time of the injury (as opposed to being engaged in recreational activities), and 13 respondents were engaged in paid work. The most common activity at the time of injury was cropping (13 respondents), followed by farm maintenance (4). Among those engaged in cropping activities, 4 were harvesting, and 4 were elevating or auguring. Nine of the cropping activities involved grain.

The mechanisms of injury included being run over or into by moving machinery (5), being caught in or between machinery (4), and being struck by falling machinery or a machinery component (4). The tractor was the most common machinery involved (7). It appeared that when adjusted for person hours, the use of a fork-lift carried the highest injury risk.

Among the associated factors investigated, the weather, light conditions, machinery age, experience with the machinery, lack of sleep, or perceived stress did not appear to be implicated. The role of other factors investigated, including eyesight, hearing, impairments, health problems, previous injury, and medication use cannot be determined without adequate comparison data. However, 8 out of the 19 reported to be working more than 40 hours per week, and 8 had a secondary occupation.

Discussion

Results

This study has confirmed that machinery is a major contributor to death and serious injury on farms. The tractor was the most frequent cause of machinery related injury, accounting for 100% of the child deaths, 71% of the adult work related deaths, and an estimated 71% of hospital admissions.

Estimates here indicate that close to one third (29%) of persons admitted to hospital for a machinery related injury on a farm were injured by agricultural machinery other than tractors. The small numbers of cases with sufficient detail limit the extent to which the non-tractor machinery can be characterised. In contrast to the injury frequencies, non-fatal injury rates per 1000 person hours from the case series study indicated that the risk of injury during operation of fork-lifts was greater than that for tractors. However, due to the small numbers in the case series, these results should be treated as preliminary.

A measure of the severity of non-fatal machinery injury on farms is that the admission rate is higher than that for general injury on farms. Further among those who were hospitalised, 35% and 37% of children and adults respectively remained in hospital for more than 2 days. In the case series study, normal working patterns were disrupted for more than 1 week for 12 of the 19 participants.

Males were more commonly killed or injured than females. However, the data presented here do not take exposure into account and exposure may well be different for males and females.

The case series study was intended to compliment the database analysis by providing more details regarding the circumstances leading up to the injurious event. However, the data obtained is limited to some extent by small numbers and response bias. Retrospective recruitment for this kind of study is clearly less than ideal. Nonetheless, the data to provide some indication of factors which may be relevant, including over-representation of those 60 years and over, and having limited time for recreational activities.

Implications for Prevention and Further Research

Almost all machinery related deaths among children on farms in this study could have been prevented by not carrying children as passengers on tractors. The alternative of adequate provision for the safety of child passengers on tractors has not yet been realised in most current tractor designs. Roll over protection frames would greatly reduce the numbers of adult tractor related deaths. This issue is currently being addressed in Victoria with a major roll over protective frame rebate scheme. A future challenge in preventing machinery related deaths on farms will be reducing the risk of run-over events. Guarding of moving parts would appear to be a solution to preventing those injuries associated with being caught in moving parts of farm machinery. However, anecdotal evidence suggests that machinery operations are not always taken into account with respect to the placement of guards. This issue requires further investigation.

The prevention of machinery injury and deaths on farms would be greatly facilitated by studies that investigate the circumstances leading up to the event among a substantial number of cases. Prospective studies which recruit participants close to the time of injury are less likely to suffer the response bias apparent with the retrospective recruitment used here. Inspection of the machinery should also be included to ascertain design features and operational factors that may be relevant to prevention. Such studies would determine the relative potential for prevention by either design solutions or work practice modification. The individual and environmental factors should also be investigated and compared with an appropriately selected group of non-injured control farmers. This approach would provide quantitative data to the farming community for the purposes of risk identification and management, and would assist in the further identification of high risk groups for prevention programs.

Sponsor:  This project was funded by the Trauma Research Foundation and through a Public Health Fellowship from the National Health and Medicine Research Council