Engaging a hard-to-reach population in research: sampling and recruitment of hired farm workers in the MICASA study

Hired farm workers provide the majority of the workforce for California's labor-intensive agricultural sector Agriculture is one of the most hazardous occupations, but there has been little research into the etiology of poor health outcomes that occur disproportionately in hired farm worker populations. MICASA is a cohort investigation of occupational and environmental health risks in hired farm worker households in Mendota, California, that employed a two-stage sampling process, including random selection of census blocks and door-to-door enumeration. The aim of this analysis was to evaluate the success of the sampling process and compare demographics of the enumerated population to other regional samples of Latino populations. In the enumeration, 1257 addresses were mapped and 729 hired farm worker households were enumerated. Findings showed no significant differences between the enumerated population and the resulting MICASA study sample; however, the MICASA population was more likely to be male, from Central America, work in agriculture, and have fewer years residency in the U.S. than California Health Interview Survey (CHIS) respondents. Additionally, 9.4% of the enumerated dwellings were back houses or unofficial dwellings and may have been missed by the U.S. Census 2000. Demographic comparisons between the enumerated population, census data, and CHIS data highlight the differences in these sampling methods and suggest possible demographic changes in hired farm workers in California. While difficulties in accessing hired farm workers often account for the lack of population-based research, the MICASA cohort provides an opportunity to examine occupational health patterns relevant to other farm worker populations.     

An analysis of self-reported joint pain among New York farmers

Data from the telephone interview portion of the New York State Farm Family Health and Hazard Surveillance Project were used to study the prevalence and predictors of joint pain in a cohort of farmers and farm residents. The participants were owner/operators, workers, and residents from a representative sample of farms from 12 New York counties. A total of 1706 participants completed a telephone interview on musculoskeletal conditions. Joint trouble was defined as self-reported aches, pain, or discomfort in the past year in each of five different joint areas. The 12-month prevalence of joint trouble was: lower back 41%, neck/shoulders 35%, knees 29%, hands/wrists 28%, and hips 15%. Using logistic regression modeling, significant risk factors for joint trouble were identified (p < 0.05). Older age and being female increased the risk of aches, pain, or discomfort in most joints. Being the owner/operator increased the risk of neck/shoulder and lower back trouble, and being a worker increased the risk of neck/shoulder trouble. Doing tractor work was associated with trouble in all five joint areas, and milking was associated with knee trouble. These findings indicate that personal risk factors and the intensity and nature of the farm work contribute to joint trouble. Ergonomic improvements to tractors and milking facilities should be a high priority.     

Nonfatal occupational injury among California farm operators

We conducted a population-based telephone survey addressing farm-work-related (FWR) injuries among California farm operators. Of 1947 participants (80.4% response), 135 farm operators reported 160 FWR injuries in the preceding year, yielding a one-year cumulative incidence for any FWR injury of 6.9% (95% CI 5.8%-8.2%), or a mean 8.2 FWR injuries per 100 farmers in the preceding year (95% CI 6.8-9.7). Multiple injury events in the same individual occurred more frequently than predicted by chance. Sprains and strains (29.4%) were the most frequently reported injury and predominantly involved the back. Overexertion represented the most frequent external cause (24.2%), followed by machinery (14.3%), falls (13.0%), and animals (12.4%). Factors associated with FWR injury included white ethnicity (OR 3.19; 95% CI 1.38-7.36), increased annual hours worked on the farm, low levels of administrative work, and increased percentage of time working with livestock. FWR injury experience of California farm operators is comparable with that reported for other agricultural populations. Above-expected frequency of multiple injuries supports involvement of personal or environmental risk factors. Preventive efforts should focus on higher-risk groups and preventing overexertion and muscle strain and injury related to machinery, falls, and animals, especially livestock.     

Expected injury cost indices on Finnish farms

Annually, more than 6000 work-related injuries occur on Finnish farms. One-fourth of these injuries are classified as severe, resulting in considerable economic losses to agricultural enterprises and the national economy. The injury rate among farmers is more than twice that among all employees on average. This study aimed to identify the risk factors that should be considered when targeting interventions, thus improving their cost-effectiveness. The expected injury cost (EIC) risk index method, which combines the probability of injuries with their severity and costs, was implemented. The potential risk factors included the type of agricultural operation, worker characteristics (gender, age), agricultural work tasks performed, and the geographical location of the farm enterprise. Crop production emerged as the type of agricultural operation with the highest risk index (1.12). The lowest risk index was in sheep and goat husbandry operations (0.35). The risk index was higher for men compared to women (1.11 vs. 0.77). The highest risk age group was farmers from 55 to 59 years of age (1.36). Farmers under 40 (0.17 to 0.89) and over 65 years old (0.70) had the lowest injury risks. No evidence was found that dangerous regions are concentrated in certain geographical parts of the country. The most common agricultural work tasks in which injuries occurred were the repair and maintenance of machinery and equipment, the transportation and relocation of animals, and milking. These accounted for more than one-third of all compensated work injuries in 2005. The identified risk factors could be considered when setting priorities in injury prevention and resource allocation.     

Management as a risk factor for farm injuries

The organizational injury theory focusing on management issues could provide new viewpoints on causes and prevention of injuries in agriculture. The objective of this study was to test whether the quality of farm management is associated with farm injuries. A cohort of 134 farms was used to examine the relationship between farm injuries and selected management, farm, and farm operator characteristics. The number of machines and musculoskeletal disorders were found to be risk factors for injuries (RR = 2.34, 95% CI 1.27-4.31, and RR = 1.75, 95% CI 1.14-2.69). Management quality (significant work delays) was associated with injuries (RR = 1.59, 95% CI 1.00-2.52) in univariable analysis but not in the multivariable model. Although the results for the association between injury and management quality were not conclusive, this line of research should be continued.     

Effect of age on hospitalized machine-related farm injuries among the Saskatchewan farm population

Machinery-related injuries are the leading cause of fatal and hospitalized injuries on Canadian farms. In Saskatchewan, the proportion of all farm injuries related to farm machinery exceeds that reported for all of Canada. This project examined the relationship between age and various factors associated with farm machine-related injuries in Saskatchewan. A retrospective review of hospital discharge data from the administrative data set of Saskatchewan Health was conducted using external cause of injury codes to identify cases of farm machinery injury that occurred in Saskatchewan during the period April 1, 1990, to March 31, 2000. Log linear estimates of association of various factors in four age groups were derived. There were 1,493 hospitalizations attributed to farm machinery-related injuries. Among the injured cohort, age was a predictor of the rate of injury. Significant association for nature of injury, mechanism of injury, and type of machine varied by age group. These data provide insights for a case-control study of farm machinery-related injuries with the objective of determining personal, environmental, and machine-related factors that are responsible for this serious public health issue.     

Agricultural injuries among operation household members: RRIS-II 1999

The purpose of this study was to determine the magnitude and consequences of agricultural injuries, and to reveal potential risk factors among agricultural household members. The Regional Rural Injury Study (RRIS-II) collected injury and exposure data on agricultural households of 16,538 people in Minnesota, Wisconsin, North Dakota, South Dakota, and Nebraska for each six-month period of 1999. Adjusted injury rates, consequences, and potential risk factors were identified through analyses. Selection of variables for multivariate analyses was based on a causal model. Injuries reported here occurred while the individuals were involved in activities associated with their own farm or ranch, unless otherwise stated. Estimates of injury rates and the effects of various exposures were derived by Poisson and logistic regression. These models accounted for correlation within both subject and household, and were adjusted for non-response. The rate of agricultural injury to household members on their own operation was 74.5 injuries per 1,000 persons per year. Differences in rates due to age and gender diminished when rates were calculated according to hours worked. Although only 5% of injured persons required in-patient hospitalization, 28% required emergency department treatment, and 84% required some type of professional health care. Moreover, 47% of all injuries required time off from agricultural work, and 7% required time off from non-agricultural work. In multivariate analyses, decreased risks were associated with Minnesota, and increased risks were identified for those with prior injuries and for males.This study provides a basis for further research on agricultural injuries and their prevention.     

The California Agricultural Workers Health Survey

The California Agricultural Workers Health Survey was a statewide cross-sectional household survey of 970 hired farm laborers. Randomly selected participants residing in randomly selected dwellings were recruited in seven communities representing all of the state's agricultural regions. Participants were interviewed in their preferred language by professional staff. The response rate was 83%. The comprehensive interview included self-reported health conditions, doctor-reported health conditions, work history, workplace health conditions, field sanitation, and work-related injuries. A farm workplace injury during the twelve-month period prior to the interview was reported by 6% of male workers (95% CI: 4% - 8%) and 2% of female workers (95% CI: 1% - 3%). Significant numbers of both male (41%) and female (40%) workers reported persistent pain (every day for more than one week) in the back, neck, knees, shoulders, hands, feet, or multiple body parts. The number of body parts in which female workers reported persistent pain correlated with increased years of U.S. hired farm work (Spearman r = 0.24, p < 0.01). Direct contact with pesticides from being sprayed or drifted upon among both male and female workers was associated with multiple workplace health conditions such as irritated, itchy, or water eyes (male: OR 2.9, 95% CI: 1.6 - 5.0; female: OR 13.8, 95% CI: 4.3 - 44.7). Persistent stomach aches among male and female participants was associated with being required to taste unwashed grapes for sweetness while picking (male: OR 4.6, 95% CI: 2.1 - 9.9; female: OR 5.8, 95% CI: 2.6 - 12.6).     

Psychological determinants of behaviors leading to occupational injuries and diseases in agriculture: a literature overview

Agriculture is one of the most hazardous occupational sectors, with a high prevalence of occupational injuries and work-related health problems. Most of these problems are caused by the interplay of human behavior and ergonomic factors and are thus preventable. Interventions to prevent occupational injuries and diseases among agricultural workers should aim to change risk behaviors and conditions by addressing specific behavioral determinants. To identify these factors, social cognitive models can be use that explain and predict health-related behavior. This study reviews the literature on the application of social cognitive models for the prevention of occupational injuries and diseases among agricultural workers. Studies are reviewed that apply the Health Belief Model, Theory of ReasonedAction, Theory of Planned Behavior, Transtheoretical Model of Change, or their subcomponents, to predict or change preventive behavior. Only a limited number of studies were found describing interventions that make use of these models, and those that do are often poorly documented with regard to the effect sizes and the explanatory or predictive value. It is concluded that the application of social cognitive models could significantly contribute to the effectiveness of preventive interventions in agriculture.     

Sowing the seeds of hope: providing regional behavioral health supports to the agricultural population

In 1999, project leaders from seven states (i.e., Iowa, Kansas, Minnesota, Nebraska, North Dakota, South Dakota, and Wisconsin) began to share ideas and resources for providing behavioral health assistance (i.e., mental health counseling and addictions services) to stressed farmers, ranchers, farm workers, and their families. The seven states are among those most impacted by the farm crisis of the 1980s and again by low commodity prices and disasters such as droughts and floods in the 1990s. Project leaders conferred in monthly telephone conference calls and by 2001 began meeting in semi-annual face-to-face meetings to formally agree on a mission, program components, and management structure. Administrative functions were transferred from the Wisconsin Office of Rural Health and Wisconsin Primary Healthcare Association, to AgriWellness, Inc., a regional nonprofit corporation founded to provide technical assistance, grant writing, training of service providers, and other administrative supports. The Sowing the Seeds of Hope program has become a model for the provision of behavioral health supports for the agricultural population, including development of farm stress telephone hotlines, provision of confidential and affordable outpatient mental health and substance abuse counseling, training of professional providers in agricultural behavioral health, training of indigenous farm and rural residents as outreach workers who can respond to disasters of all types, and weekend educational retreats for farm residents. The program has achieved economy of scale by sharing expertise across state boundaries and the formation of a regional administrative structure. Yet, many challenges exist, the greatest of which is obtaining ongoing permanent support for the increasing numbers of uninsured and underinsured people involved in agriculture.     

Factors associated with the prevalence of non-ROPS tractors on farms in the U.S

Rollover protective structures (ROPS) are an effective engineering control known to prevent tractor overturn deaths, the leading cause of occupational fatalities for farmers and farm workers in the U.S. However, the use of ROPS is known to vary greatly from farm to farm. A national sample of 11,458 farm operators from the 2004 Occupational Injury Surveillance of Production Agriculture (OISPA) survey was used to assess the association between the prevalence of ROPS and ten farm operator and farm demographic variables using logistic regression. The variable were: operator's age, operator's sex, operator's education, farm sales, full- or part-time farming, acreage, type of operation, number of hired workers, number of injuries, and region. All ten variables were found to have significant associations with the prevalence of non-ROPS tractors on farms in the univariate logistic regressions. For the multivariate model, all variables except for the sex of the farm operator remained significant. Farms with less than three adult injuries, no hired workers, less than 300 acres in size, a Midwest location, and a primary farm type of tobacco, fruit and nuts, dairy, or poultry and eggs all had adjusted odds ratios of 2 or greater. Increasing the prevalence of ROPS-equipped tractors is essential for reducing the leading cause of death on farms, tractor overturns. Economic factors play a major role in the prevalence and distribution of non-ROPS tractors on farms. The identified associations can be used to effectively target areas of the U.S. for ROPS promotion activities.     

Risk factors and prevalence of declined work ability among dairy farmers

Farm work, particularly with livestock, exposes farmers to injuries, occupational diseases, and disabling health conditions, which in many cases result in early retirement and loss of quality of life. The objectives of this study were to evaluate the prevalence of and risk factors for declined work ability among full-time dairy farmers. We conducted a postal survey using the standard Work Ability Index (WAI) questionnaire augmented with a form containing questions about working conditions and lifestyle factors that potentially affect work ability. We received 399 usable responses (245 female and 154 male; 41.5% response rate). The prevalence of declined work ability (poor or moderate WAI score) was 39% overall, 44% among females, and 32% among males. Older age, small herd size, lack of mental breaks from work, inadequate leisure, and non-use of alcohol were significantly associated with declined work ability. The odds ratios for these risk factors ranged from 2.04 to 4.67. Current injuries and diseases are part of the WAI questionnaire contributing to declined work ability. This study indicates that interventions are needed, particularly among older farmers and farmers with injuries or diseases, to restore their work ability. Life-long measures to maintain work ability are also important, preventing the steep decline in work ability currently occurring among older farmers. Based on this study, we recommend guidance addressing the identified risk factors, particularly the importance of organizing both farm and domestic work with adequate rest, leisure time, and mental breaks as counterbalance to the daily workload among livestock farmers.     

Farm safety issues in Old Order Anabaptist communities: unique aspects and innovative intervention strategies

The Amish and other Old Order Anabaptists have been inseparably linked with agriculture since coming to America. However few efforts have been identified which analyze the issues involved with Old Order Anabaptist farm injuries or present best practices for addressing these problems. As part of an effort to develop culturally appropriate and effective injury prevention strategies for use within the Old Order Anabaptist community, this article identifies important cultural issues that should be considered in understanding and attempting to reduce farm injures in this population, summarizes statistics concerning farm-related fatalities among Old Order Anabaptists, and discusses methods which have been effectively used to address farm injuries within these communities. In the statistical analysis, 92 cases were identified that were classified as being work-related or occurring in a farm work-related setting during the period 1980 to 2000. Approximately 64% of the identified cases were children 15 years and under; and approximately 77% were male. Run-over incidents were the most frequent primary cause of the fatal injuries, while animal-related behavior was the most frequent secondary cause, reflecting agricultural practices that remain highly dependent upon the use of horses and mules. The authors believe evidence suggests that certain Old Order Anabaptist choices concerning farm safety issues may be directly related to their socio-religious beliefs, and that effective intervention strategies must also be sensitive to socio-religious beliefs.     

Fatal injuries in Finnish agriculture, 1988-2000

Agriculture is one of the most hazardous industries in Finland. The aim of this study was to describe and analyze fatal farm injuries in Finland in 1988 to 2000. The information regarding farm-related fatalities was collected by the Kuopio Regional Institute of Occupational Health. The material of this study consisted of all fatal injuries that occurred on a farm or away from a farm in the course of agricultural work. A total of 217 farm-related fatalities occurred in Finland between 1988 and 2000. Of these, 120 were tractor-related, and 97 were other fatal farm injuries. Most of the injuries involved middle-aged or older male farmers. The most typical fatalities with tractors were tractor overturns during driving on a road or working in a field. Other fatal farm incidents occurred mainly in construction work, animal husbandry, or forest work. Elderly farmers and children proved to be risk groups for fatal injuries.     

Eye injury in migrant farm workers and suggested hazard controls

The eyes are a common site of injury in agricultural operations. Identification of the cause of injury is important to inform preventive interventions. The objective of this study was to describe the hazards and mechanisms of acute traumatic injury to the eyes of agricultural workers who are hired in farming operations on a seasonal basis. A review of the literature was performed to summarize the mechanisms of eye injuries in agriculture. Field observations and informal interviews were performed to verify the literature and to determine whether there are eye hazards for farm workers that have not been reported in the literature. Additional mechanisms of injury were elicited, and suggested methods of injury prevention are presented here.     

Mortality and morbidity in agriculture in the United States

This article summarizes the trends in agricultural injuries and illnesses in the past decade, as well as the needs for surveillance in the future. Agriculture is one of the most hazardous industries in the U.S. The fatality rate in agriculture remained high (about 22/100,000 workers) through the 1990s. and tractors remained the leading source of death, causing approximately 300 fatalities each year. Non-fatal injuries and illnesses decreased in the employed agricultural worker population. There are no adequate injury and illness data for self-employed farmers and family members to show trends over time. The reported injury rates have been 0.5 to 16.6/100 workers, based on the source of information. Many studies have shown high rates of respiratory and musculoskeletal symptoms, hearing loss, and skin disorders in agriculture. The overall cancer rate is lower; however, certain cancers are elevated in farmers. Surveillance information has not improved significantly in the past decade; however, many studies have provided more insight into the prevalence, incidence, and risk factors for injury and illness. Further efforts are needed to better define the populations at risk, including farmers and ranchers, family members, workers, migrant and seasonal workers, and others exposed to farm hazards. Fatalities are well documented, and it is important to continue existing surveillance in the future. Surveillance systems should be developed to collect information on agriculture-related non-fatal injuries and illnesses.     

Disease and injury among participants in the Agricultural Health Study

The Agricultural Health Study (www.aghealth.org) is a cohort of 89,658 pesticide applicators and their spouses from Iowa and North Carolina assembled between 1993 and 1997 to evaluate riskfactorsfor disease in ruralfarm populations. This prospective study is just now reaching sufficient maturity for analysis of many disease endpoints. Nonetheless, several analyses have already provided interesting and important leads regarding disease patterns in agricultural populations and etiologic clues for the general population. Compared to the mortality experience of the general population in the two states (adjusted for race, gender, age and calendar time), the cohort experienced a very low mortality rate overall and for many specific causes and a low rate of overall cancer incidence. A few cancers, however, appear elevated, including multiple myeloma and cancers of the lip, gallbladder, ovary, prostate, and thyroid, but numbers are small for many cancers. A study of prostate cancer found associations with exposure to several pesticides, particularly among individuals with a family history of prostate cancer. Links to pesticides and other agricultural factors have been found for injuries, retinal degeneration, and respiratory wheeze. Methodological studies have determined that information collected by interview is unbiased and reliable. A third round of interviews scheduled to begin in 2005 will collect additional information on agricultural exposures and health outcomes. The study can provide data to address many health issues in the agricultural community. The study investigators welcome collaboration with interested scientists.     

A community-based telephone survey of work and injuries in teenage agricultural workers

In order to estimate the one-year cumulative incidence of work-related injuries in teenage agricultural workers and to characterize the patterns and types of agricultural work performed by teenagers, we performed a community-based random-digit dialing telephone survey. We used a sampling frame of farm and non-farm households to access information on teenage agricultural workers. An agricultural community in eastern Washington State was selected due to the high number of teenage youth and its agricultural economy. Teenage agricultural workers who worked for an agricultural business owned by one of their family members were more likely to work a greater number of seasons, work fewer hours per week, perform tasks involving driving, animal care, and mechanic work, and were less likely to be seasonal workers or work in the harvest than teenagers who did not work for a family member. A similar pattern of work differences was seen when comparing non-Hispanic to Hispanic agricultural workers. Teenagers working for a family member in agriculture had a higher injury rate than teenagers working for an agricultural business not owned by a family member. The injury rate among Hispanic teenage agricultural workers was also higher than that of non-Hispanics.     

Occupational health survey of farm workers by camp health aides

Little is known about the magnitude of occupational health problems among migrant farm workers. A community-based cross-sectional survey was conducted in two migrant farm worker communities: Homestead, Florida, and Kankakee, Illinois. Camp Health Aides (CHAs) interviewed 425 workers about job tasks, personal protective equipment (PPE), field sanitation, work exposures, and selected health conditions. Limited provision of personal protective equipment was reported among those reporting early re-entry tasks: 35% in Kankakee and 42% in Homestead were provided gloves, and 22% in Homestead and 0% in Kankakee were provided protective clothing. About two-thirds were provided toilet facilities and water for hand-washing. Workers reported high prevalences of health conditions consistent with exposure to ergonomic hazards and pesticides. The prevalence of back pain in the past 12 months was 39% in Homestead and 24% in Kankakee. Among Homestead participants, 35% experienced eye symptoms, while 31% reported skin symptoms. These symptoms were less prevalent among Kankakee participants (16% for both eye and skin symptoms). Specific areas of concern included back pain associated with heavy lifting and ladder work; eye and skin irritation associated with fertilizer application tasks and with working in fields during or after spraying of chemicals, especially early re-entry of sprayed fields; and skin irritation associated with a lack of access to hand-washing facilities. In both Kankakee and Homestead, better adherence to safety standards is needed, as well as greater efforts to implement solutions that are available to help prevent work-related musculoskeletal problems.     

Farmwork-related injury among farmers 50 years of age and older in Kentucky and South Carolina: a cohort study, 2002-2005

Farmers in the U.S. are becoming more diverse; the average age of the farmer is increasing, as is the number of women and minority farm operators. There is limited research on injury risk factors in these special populations of farmers. It is especially important to study the risk factors for injury in these growing and at-risk groups. A longitudinal survey was conducted of farmers (n = 1,394) age 50 and older who resided in Kentucky and South Carolina. The questionnaire was administered by telephone and mail surveys four times between 2002 and 2005 to the fixed cohort of farmers, obtained by convenience sample. Approximately half of the cohort was female, and the majority of the cohort worked less than 40 hours per week. This cohort reported a crude, non-fatal injury rate of 9.3 injured farmers per 100 per year. Farmers reporting chronic bronchitis/emphysema (estimated odds ratio [EOR] = 1.57), back problems (EOR = 1.37), arthritis (EOR = 1.31), 3 to 4 restless nights in the past week (EOR = 2.02), or 5 to 7 restless nights in the past week (EOR = 1.82) were at significantly higher odds of sustaining a farmwork-related injury as calculated by the generalized estimating equations (GEE) regression method Farmers operating equipment on highways (EOR = 1.51) or climbing higher than eight feet (EOR = 1.69) were at significantly higher odds of sustaining a farmwork-related injury, and females were at higher risk of injury when performing animal-related tasks (EOR = 3.00) or crop-related tasks (EOR = 2.21). Identified factors associated with farmwork-related injury should better inform agricultural health policies and guidelines for older farmers, such as policies governing the allowable number of hours worked per week and rest breaks, guidelines that advise appropriate types of farm tasks, and ergonomic engineering advances on farming equipment.