Amid. Anal. & Prev. Vol. 23. No. 6, pp. 565-594 1991 Printed in Great Britain.
ooo14575/91 53.00 + .oo 0 1991 Pergamon Press pk
NONFATAL FARM INJURIES IN EASTERN ONTARIO: A RETROSPECTIVE SURVEY* ROBERT JAMES BRISON and CHARLES WILLIAM LAWRENCE PICKET-T Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario, Canada, K7L3N6 (Received 16 July 1990; in revised form 12 November 1990) Abstract-A one-year retrospective survey was conducted to study the incidence of, and potential risk factors for farm-related injuries. One hundred thirteen dairy and beef farms in Eastern Ontario were surveyed using a personal interview. Information was collected on demographic characteristics of the farm owner, workers, and family; characteristics of the farm operation; and information on behaviours potentially affecting injury risk. The crude rate of injury was 9.6 per 100 person years. Significantly higher rates of injury were found for: owner-operators of farms (RR = 2.9; p < 0.001); male sex (RR = 3.8; p < 0.001); living/working on a beef as opposed to dairy farm (RR = 2.3; p = 0.01); farm owners in the age groups of 70 years (p = 0.05), full-time as opposed to part-time beef farm owners (RR = 4.2; p = 0.02); and full-time owners of beef as opposed to dairy farms (RR 2.4; p = 0.03). Common patterns of injury included accidental falls (E880-8); lacerations, bruises, and crush injuries from working with cattle (E906) or from agricultural machinery (E919.0); and foreign body injuries to the eye (E914). Few injuries were associated with the use of tractors or power take-offs. 82% of injuries, for which medical treatment was sought, were treated in a hospital-based emergency department. This information would support efforts to establish an emergency-department-based surveillance system for farming injuries in our setting.
INTRODUCTION
Farming is the second most hazardous occupation in Ontario in terms of mortality. The death rate due to injury of Ontario farm workers is very close that observed in miners and is twice that observed in construction workers (Richards 1985). Despite this fact, few researchers in Ontario or Canada have examined the incidence or etiology of farmrelated injuries. The need for such epidemiological study in Canada has been recognized by provincial, national, and international associations (Chong 1985; Richards 1985; Rennie and Sadlier-Brown 1989; Donaldson 1968; American Academy of Pediatrics 1988). Risk factors for farm injury should be identifiable to assist in the development and targeting of injury prevention measures. Previously suggested risk factors include: inadequate training and supervision (Chong 1985; Walker and Raines 1982); long working hours (Swanson et al. 1987); isolated location (Gilmore, Clemmer, and Orme 1981); lack of use of protective equipment (Karlson and Noren 1979; Payton 1986); and low income from farm operations (Salmi, Peterson, and Sattin 1989). It has been previously suggested that farm children are at a particularly high risk for farm-related injury (Cogbill, Busch, and Stiers 1985; Doyle and Conroy 1989a; Rivara 1985; Salmi et al. 1989). Unlike other occupations, children on farms comprise a significant proportion of the workforce. They live and play amongst the unique hazards associated with farm buildings, equipment, animals, and properties. While the importance of child injuries on Ontario farms has been previously recognized (Richards 1985), research is needed to quantify the scope of the problem. Most fatal injuries on farms are associated with farm tractor accidents, either through tractor rollovers (Centers for Disease Control 1983; Goodman et al. 1985) or entanglements with power-take-off devices (McElfresh and Bryan 1973). The absence of protective structures such as rollbars and safety shields is often a contributing factor in tractor-related deaths (Chong 1985). Other farm machines that have been identified as sources of nonfatal trauma include *This research was funded by a grant from the Emergency Health Services Branch of the Ontario Ministry of Health. 585
5X6
R. J. BRISON and C. W. L. PICKET-T
corn pickers (Campbell et al. 1979), hay balers (Mayba 1984), chainsaws (Doyle and Conroy 1989c), and grain augers (Letts and Gammon 1978). Studies of nonfatal injuries that do not focus on farm machines are Iess common. Busch et al. (1986) investigated severe animal-retated injuries on farms using a hospital chart review. They determined that most of these injuries were orthopedic, neurologic, maxillofacial, thoracic, abdominal, or spinal in nature. Napier et al. (9185) attempted, with very limited success, to isolate predictive factors associated with farm accidents in Ohio. They concluded that the state of knowledge about farm accidents and their etiology was not as advanced as the literature suggested. Commonly stated explanations of farm accidents had little utility in predicting their frequency. Doyle and Conroy (1989b) reported on the spectrum of farm accidents seen within general practice in the Republic of Ireland. A seasonal peak in the number of injuries treated by general practitioners was observed during the summer months. Alcohol, medication, or illness were not found to be contributory factors for these accidents. We had the opportunity to retrospectively survey farm-related injuries in the rural region surrounding the City of Kingston, Ontario, Canada. Two objectives were addressed in this research. First, the incidence of farm-related injuries on 113 dairy and beef farms was determined. Second, the significance of several potential risk factors for injury on these farms was assessed. It was hoped that these inquiries would contribute to the development of preventive strategies aimed at a reduction in the incidence and severity of farm-related injuries in Ontario. METHODS
Interviews were conducted between July 1989 and January 1990. The area of study included farms which were in the 60 km (40 mile) catchment area of the Kingston Health Sciences Complex. This complex includes the two teaching hospitals that provide emergency health services for most of this farm population. The official farm registry from the 1986 Canada Census of Agriculture was used as the source of subjects for this study. An income criterion (annual farm sales in excess of 10,000 Canadian dollars) was used in the selection of farms. This helped to minimize the number of hobby farms within the sample. Only beef and dairy operations that were actively farming at the time of the 1986 census were eligible for selection; the majority (85%) of Kingston area farms are engaged in these types of farming (Statistics Canada, personal communication, 1989). Eight hundred and eighty-five farms met these inclusion criteria. Two hundred beef and 200 dairy farms were randomly selected for study from this list. Farm owners chosen for study were sent a recruitment package by mail. This package contained a letter explaining the objectives and the voluntary nature of the study, letters of support from two agricultural organizations, and a business reply card. Those farmers agreeing to participate returned the card to the study center. Nonrespondents were sent reminder letters and reply cards at one month, and, if necessary, four months after the initial contact. Personal interviews were conducted with a representative from each participating farm. A standard demographic questionnaire was used in acquiring information about individual farm operations and their owners. The variables contained in this questionnaire are listed in Table 1. An owner-operator was classified as a part-time farmer if he or she held “off-farm” employment on a full-time basis. Education levels were categorized as primary, secondary, or postsecondary. Farms were grouped into three sizes according to their tiliabie acreage (400 acres). A farm type of “Other” refers to those operations that had ceased operating as beef or dairy ventures since the 1986 Canada Census of Agriculture. Equipment present on the farm was described in an attempt to quantify the level of mechanization on each operation. A PTO (power-take-off device) is an extension of the driveshaft of a farm tractor that is used to transmit power from tractors to farm
Nonfatal farm injuries in Eastern Ontario
581
Table 1. Information collected from farm representatives Farm operation characteristics 1. Tillable acreage (including rented land) 2. Type of farm (Beef, Dairy, or Other) 3. Gross 1988 farm sales 4. Number of people working or living on farm 5. Age, sex. relationship to owner, and one-year injury history of each person on the farm Farm owner characteristics 6. Age 7. Sex 8. Working status (Full-time or part-time) 9. Education level 10. Marital status Equipment Description 11. Number of tractors 12. Number of farm implements 13. Average age of farm implements 14. Number of farm implements powered by PTO Other variables 15. Presence of rollover protection
on tractors 16. Need to travel on busy roads with equipment 17. Seat belt use in vehicles (by owner-operator) 18. Use of tobacco products (by owner-operator) 19. Alcohol use (by owner-operator) 20. Farm stress index
implements. These devices rotate at high speeds and can be an important agent of serious traumatic injury on farms (McElfresh and Bryan 1973). The “Other Variables” noted in Table 1 were selected as crude measures of operational and behavioural risk attributable to the farms and their owners. Farms that had at least one tractor with either a rollbar or a crushproof cab were categorized separately from those without any of these protective devices. Similarly, farms that required regular travel on busy public roads with farm equipment were distinguished from those in quieter settings. Within-vehicle seat belt use was ranked by the owneroperators using a five point scale from 1 (never used) to 5 (always used). Tobacco use (current smoker vs. nonsmoker) was reported dichotomously. Alcohol use was reported using a frequency index that ranged from 1 (3 or more alcoholic drinks per day) to 8 (abstinence). Finally, the farmers reported the amount of stress they generally perceived themselves to be under from their farming operations on a rank scale from 1 (never under stress) to 5 (constantly under stress). Farm-related injuries reported to have occurred in the year prior to the interview were recorded. These included injuries to farm owners or managers and their spouses, children, or other farm family; to farm employees; and to visitors to the farm. A person was considered injured if (i) he or she made use of the Ontario health care system to treat an injury, or (ii) he or she was unable to do a normal, daily working activity due to the injury (whether or not time was actually lost from work). Injury information collected included an injury description, the mechanism of injury, the date of the incident (month), and a generic description of the location of medical treatment. ICD-9-CM E-Codes allow the classification of injuries based upon environmental events, circumstances, and conditions as the causes of injury (U.S. Department of Health and Human Services 1989). All reported farm injuries were categorized by E-Code, as well as by injury type and body part injured. Analysis
Participant and nonparticipant farms were compared using univariate statistics, on the basis of 20 operational variables collected during the 1986 Canada Census of Agriculture. Crude rates of injury were calculated for the study population. The numerator in these rates was the number of farm-related injuries that occurred in the year prior to MP 23:6-R
588
R. J. BRISONand C. W. L. PICKE~-~
interview. Person-years of work and/or habitation on the farms were used in the denominators. Specific injury rates were also estimated for (i) farm owner-operators, (ii) spouses of owner-operators, (iii) farm children, (iv) other farm family members, and (v) fulltime farm employees. Age-specific, sex-specific, and farming type-specific incidence rates were also calculated. The numerator in these rates was the number of people injured (as opposed to the number of injuries) in the year prior to interview. The statistical significance of potential risk factors for injury was described using univariate (chi-square) statistics. First, demographic risk factors were examined for all people who worked and/or resided on these farms. Second, personal and operational characteristics that were potentially associated with injuries specifically to farm owners were assessed. Analyses were performed using the SAS statistical package (SAS Institute, Inc. 1985). RESULTS
Three hundred ninety-one letters were mailed to potential study participants. After three mailings, 160 farms had responded to the appeal, for a response rate of 41%. Of these, 47 potential subjects did not participate in the study. Reasons for nonparticipation included: “farm inactive” (n = 31), “subject deceased” (n = 3), and “refusal to participate” (n = 13). The 31 inactive farms were excluded from the denominator. The remaining 113 farms, therefore, represented a participation rate of 31%.
Table 2. Comparison of participant and nonparticipant farms using data from the 1986 Agricultural Census of Canada Mean (Standard Error) or % Variable*
Participants (N = 113)
Nonparticipants (N = 278)
Acreage: Worked Owned Total crops
410.0 (24.9) 319.0 (20.1) 156.2 (10.4)
408.8 (18.8) 299.0 (13.9) 154.4 ( 8.7)
0.97 0.41 0.91
Cattle: Bulls >l Year Dairy cows Beef cows Steers Calves
ooo14575/91 53.00 + .oo 0 1991 Pergamon Press pk
NONFATAL FARM INJURIES IN EASTERN ONTARIO: A RETROSPECTIVE SURVEY* ROBERT JAMES BRISON and CHARLES WILLIAM LAWRENCE PICKET-T Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario, Canada, K7L3N6 (Received 16 July 1990; in revised form 12 November 1990) Abstract-A one-year retrospective survey was conducted to study the incidence of, and potential risk factors for farm-related injuries. One hundred thirteen dairy and beef farms in Eastern Ontario were surveyed using a personal interview. Information was collected on demographic characteristics of the farm owner, workers, and family; characteristics of the farm operation; and information on behaviours potentially affecting injury risk. The crude rate of injury was 9.6 per 100 person years. Significantly higher rates of injury were found for: owner-operators of farms (RR = 2.9; p < 0.001); male sex (RR = 3.8; p < 0.001); living/working on a beef as opposed to dairy farm (RR = 2.3; p = 0.01); farm owners in the age groups of 70 years (p = 0.05), full-time as opposed to part-time beef farm owners (RR = 4.2; p = 0.02); and full-time owners of beef as opposed to dairy farms (RR 2.4; p = 0.03). Common patterns of injury included accidental falls (E880-8); lacerations, bruises, and crush injuries from working with cattle (E906) or from agricultural machinery (E919.0); and foreign body injuries to the eye (E914). Few injuries were associated with the use of tractors or power take-offs. 82% of injuries, for which medical treatment was sought, were treated in a hospital-based emergency department. This information would support efforts to establish an emergency-department-based surveillance system for farming injuries in our setting.
INTRODUCTION
Farming is the second most hazardous occupation in Ontario in terms of mortality. The death rate due to injury of Ontario farm workers is very close that observed in miners and is twice that observed in construction workers (Richards 1985). Despite this fact, few researchers in Ontario or Canada have examined the incidence or etiology of farmrelated injuries. The need for such epidemiological study in Canada has been recognized by provincial, national, and international associations (Chong 1985; Richards 1985; Rennie and Sadlier-Brown 1989; Donaldson 1968; American Academy of Pediatrics 1988). Risk factors for farm injury should be identifiable to assist in the development and targeting of injury prevention measures. Previously suggested risk factors include: inadequate training and supervision (Chong 1985; Walker and Raines 1982); long working hours (Swanson et al. 1987); isolated location (Gilmore, Clemmer, and Orme 1981); lack of use of protective equipment (Karlson and Noren 1979; Payton 1986); and low income from farm operations (Salmi, Peterson, and Sattin 1989). It has been previously suggested that farm children are at a particularly high risk for farm-related injury (Cogbill, Busch, and Stiers 1985; Doyle and Conroy 1989a; Rivara 1985; Salmi et al. 1989). Unlike other occupations, children on farms comprise a significant proportion of the workforce. They live and play amongst the unique hazards associated with farm buildings, equipment, animals, and properties. While the importance of child injuries on Ontario farms has been previously recognized (Richards 1985), research is needed to quantify the scope of the problem. Most fatal injuries on farms are associated with farm tractor accidents, either through tractor rollovers (Centers for Disease Control 1983; Goodman et al. 1985) or entanglements with power-take-off devices (McElfresh and Bryan 1973). The absence of protective structures such as rollbars and safety shields is often a contributing factor in tractor-related deaths (Chong 1985). Other farm machines that have been identified as sources of nonfatal trauma include *This research was funded by a grant from the Emergency Health Services Branch of the Ontario Ministry of Health. 585
5X6
R. J. BRISON and C. W. L. PICKET-T
corn pickers (Campbell et al. 1979), hay balers (Mayba 1984), chainsaws (Doyle and Conroy 1989c), and grain augers (Letts and Gammon 1978). Studies of nonfatal injuries that do not focus on farm machines are Iess common. Busch et al. (1986) investigated severe animal-retated injuries on farms using a hospital chart review. They determined that most of these injuries were orthopedic, neurologic, maxillofacial, thoracic, abdominal, or spinal in nature. Napier et al. (9185) attempted, with very limited success, to isolate predictive factors associated with farm accidents in Ohio. They concluded that the state of knowledge about farm accidents and their etiology was not as advanced as the literature suggested. Commonly stated explanations of farm accidents had little utility in predicting their frequency. Doyle and Conroy (1989b) reported on the spectrum of farm accidents seen within general practice in the Republic of Ireland. A seasonal peak in the number of injuries treated by general practitioners was observed during the summer months. Alcohol, medication, or illness were not found to be contributory factors for these accidents. We had the opportunity to retrospectively survey farm-related injuries in the rural region surrounding the City of Kingston, Ontario, Canada. Two objectives were addressed in this research. First, the incidence of farm-related injuries on 113 dairy and beef farms was determined. Second, the significance of several potential risk factors for injury on these farms was assessed. It was hoped that these inquiries would contribute to the development of preventive strategies aimed at a reduction in the incidence and severity of farm-related injuries in Ontario. METHODS
Interviews were conducted between July 1989 and January 1990. The area of study included farms which were in the 60 km (40 mile) catchment area of the Kingston Health Sciences Complex. This complex includes the two teaching hospitals that provide emergency health services for most of this farm population. The official farm registry from the 1986 Canada Census of Agriculture was used as the source of subjects for this study. An income criterion (annual farm sales in excess of 10,000 Canadian dollars) was used in the selection of farms. This helped to minimize the number of hobby farms within the sample. Only beef and dairy operations that were actively farming at the time of the 1986 census were eligible for selection; the majority (85%) of Kingston area farms are engaged in these types of farming (Statistics Canada, personal communication, 1989). Eight hundred and eighty-five farms met these inclusion criteria. Two hundred beef and 200 dairy farms were randomly selected for study from this list. Farm owners chosen for study were sent a recruitment package by mail. This package contained a letter explaining the objectives and the voluntary nature of the study, letters of support from two agricultural organizations, and a business reply card. Those farmers agreeing to participate returned the card to the study center. Nonrespondents were sent reminder letters and reply cards at one month, and, if necessary, four months after the initial contact. Personal interviews were conducted with a representative from each participating farm. A standard demographic questionnaire was used in acquiring information about individual farm operations and their owners. The variables contained in this questionnaire are listed in Table 1. An owner-operator was classified as a part-time farmer if he or she held “off-farm” employment on a full-time basis. Education levels were categorized as primary, secondary, or postsecondary. Farms were grouped into three sizes according to their tiliabie acreage (400 acres). A farm type of “Other” refers to those operations that had ceased operating as beef or dairy ventures since the 1986 Canada Census of Agriculture. Equipment present on the farm was described in an attempt to quantify the level of mechanization on each operation. A PTO (power-take-off device) is an extension of the driveshaft of a farm tractor that is used to transmit power from tractors to farm
Nonfatal farm injuries in Eastern Ontario
581
Table 1. Information collected from farm representatives Farm operation characteristics 1. Tillable acreage (including rented land) 2. Type of farm (Beef, Dairy, or Other) 3. Gross 1988 farm sales 4. Number of people working or living on farm 5. Age, sex. relationship to owner, and one-year injury history of each person on the farm Farm owner characteristics 6. Age 7. Sex 8. Working status (Full-time or part-time) 9. Education level 10. Marital status Equipment Description 11. Number of tractors 12. Number of farm implements 13. Average age of farm implements 14. Number of farm implements powered by PTO Other variables 15. Presence of rollover protection
on tractors 16. Need to travel on busy roads with equipment 17. Seat belt use in vehicles (by owner-operator) 18. Use of tobacco products (by owner-operator) 19. Alcohol use (by owner-operator) 20. Farm stress index
implements. These devices rotate at high speeds and can be an important agent of serious traumatic injury on farms (McElfresh and Bryan 1973). The “Other Variables” noted in Table 1 were selected as crude measures of operational and behavioural risk attributable to the farms and their owners. Farms that had at least one tractor with either a rollbar or a crushproof cab were categorized separately from those without any of these protective devices. Similarly, farms that required regular travel on busy public roads with farm equipment were distinguished from those in quieter settings. Within-vehicle seat belt use was ranked by the owneroperators using a five point scale from 1 (never used) to 5 (always used). Tobacco use (current smoker vs. nonsmoker) was reported dichotomously. Alcohol use was reported using a frequency index that ranged from 1 (3 or more alcoholic drinks per day) to 8 (abstinence). Finally, the farmers reported the amount of stress they generally perceived themselves to be under from their farming operations on a rank scale from 1 (never under stress) to 5 (constantly under stress). Farm-related injuries reported to have occurred in the year prior to the interview were recorded. These included injuries to farm owners or managers and their spouses, children, or other farm family; to farm employees; and to visitors to the farm. A person was considered injured if (i) he or she made use of the Ontario health care system to treat an injury, or (ii) he or she was unable to do a normal, daily working activity due to the injury (whether or not time was actually lost from work). Injury information collected included an injury description, the mechanism of injury, the date of the incident (month), and a generic description of the location of medical treatment. ICD-9-CM E-Codes allow the classification of injuries based upon environmental events, circumstances, and conditions as the causes of injury (U.S. Department of Health and Human Services 1989). All reported farm injuries were categorized by E-Code, as well as by injury type and body part injured. Analysis
Participant and nonparticipant farms were compared using univariate statistics, on the basis of 20 operational variables collected during the 1986 Canada Census of Agriculture. Crude rates of injury were calculated for the study population. The numerator in these rates was the number of farm-related injuries that occurred in the year prior to MP 23:6-R
588
R. J. BRISONand C. W. L. PICKE~-~
interview. Person-years of work and/or habitation on the farms were used in the denominators. Specific injury rates were also estimated for (i) farm owner-operators, (ii) spouses of owner-operators, (iii) farm children, (iv) other farm family members, and (v) fulltime farm employees. Age-specific, sex-specific, and farming type-specific incidence rates were also calculated. The numerator in these rates was the number of people injured (as opposed to the number of injuries) in the year prior to interview. The statistical significance of potential risk factors for injury was described using univariate (chi-square) statistics. First, demographic risk factors were examined for all people who worked and/or resided on these farms. Second, personal and operational characteristics that were potentially associated with injuries specifically to farm owners were assessed. Analyses were performed using the SAS statistical package (SAS Institute, Inc. 1985). RESULTS
Three hundred ninety-one letters were mailed to potential study participants. After three mailings, 160 farms had responded to the appeal, for a response rate of 41%. Of these, 47 potential subjects did not participate in the study. Reasons for nonparticipation included: “farm inactive” (n = 31), “subject deceased” (n = 3), and “refusal to participate” (n = 13). The 31 inactive farms were excluded from the denominator. The remaining 113 farms, therefore, represented a participation rate of 31%.
Table 2. Comparison of participant and nonparticipant farms using data from the 1986 Agricultural Census of Canada Mean (Standard Error) or % Variable*
Participants (N = 113)
Nonparticipants (N = 278)
Acreage: Worked Owned Total crops
410.0 (24.9) 319.0 (20.1) 156.2 (10.4)
408.8 (18.8) 299.0 (13.9) 154.4 ( 8.7)
0.97 0.41 0.91
Cattle: Bulls >l Year Dairy cows Beef cows Steers Calves
