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Hired Farm Worker Health Needs Assessment -- Don Villarejo

Don Villarejo, Ph.D.

P.O. Box 381

Davis, CA 95617

(530)756-6545 voice & facsimile

This project was supported by a grant from The California Endowment to the California Institute for Rural Studies. Project Principal Investigator was Don Villarejo from October 1998 through June 1999. David Lighthall assumed that responsibility, effective July 1, 1999. Co-investigators are Bonnie Bade and Steve McCurdy. Steve Samuels is Project Bio-statistician. Daniel Williams III was Project Coordinator from October 1998 through July 2000. Bade, Williams and Anne Souter were Site Coordinators for the project. Data entry for the physical examinations and risk behavior questionnaires was provided by the California Department of Health Services, while for the main survey instrument it was provided by Research Support Services.


Surprising little is known about the health status of U.S. hired farm workers and their families. Despite the plethora of Federal and State programs that provide health services for hired farm workers, the supporting government agencies fund little or no fundamental research on this population. Nearly all health status data collected by these agencies is obtained exclusively from the self-selected population seeking to utilize the services they provide. Similarly, the National Center for Health Statistics and the Center for Disease Control are, even today, unable to provide even rudimentary information about the health status of the nation’s hired farm labor force. Recent reviews of the medical literature recently concluded that there exists no baseline data at all regarding the health status of U.S. hired farm workers or their family members (Mobed et al, 1992; Villarejo and Baron, 1999).

A 1990 initiative of the U.S. Surgeon General promised that, for the first time, the health and safety of all who work on the nation’s farms would, henceforth, be a high priority of Federal programs. Stimulated by a strongly worded Senate resolution authored by U.S. Sen. Tom Harkin, new Federal resources were allocated to develop research and interventions to address health and safety issues in agriculture. The focus of the Harkin resolution was ‘farm families,’ which was widely interpreted at the time to refer to farm operators and unpaid family members. However, the Surgeon General explicitly designated hired farm workers as a population that was to be served, on an equal footing with farmers, in this effort. Sen. Harkin applauded this interpretation of his resolution.

The National Institute for Occupational Safety and Health (NIOSH) was chosen to be the lead agency, and, in 1990, it established six regional Agricultural Health and Safety centers, mostly based at land grant universities. In later years, three more centers were added. Each is sited in one of the nation’s major agricultural regions, as is further described in Table 1.

Table 1. NIOSH-sponsored Agricultural Health & Safety Centers

Deep South Center for Agricultural Disease & Injury Research, Education & Prevention,

Tampa, FL

Great Plains Center for Agricultural Health, Iowa City, IA

High Plains Intermountain Center for Agricultural Health & Safety, Ft. Collins, CO

Midwest Center for Agricultural Research, Education, and Disease & Injury Prevention,

Marshfield, WI

Northeast Center for Agricultural & Occupational Health, Cooperstown, NY

Pacific Northwest Agricultural Safety & Health Center, Seattle, WA

Southeast Center for Agricultural Health, Injury Prevention & Education, Lexington, KY

Southwest Center for Agricultural Health, Injury Prevention & Education, Tyler, TX

University of California Agricultural Health & Safety Center, Davis, CA


In addition to the centers, NIOSH also provided substantial resources in support of intramural research within the agency and in support of a series of extramural, competitive grant programs. While none of these efforts were earmarked for research on hired farm workers, NIOSH welcomed proposals that did so.

Topics for which NIOSH solicited research proposals included: Farm Family Health & Hazard Surveillance, Childhood Agricultural Injury, Agricultural Injury Research & Prevention, and Community Partners for Agricultural Health and Safety. In each of these thematic areas, some of the proposals that were funded focused exclusively on hired farm workers.

Shortly following the change of political power in the Executive Branch of the Federal government represented by the 1992 Presidential election, other agencies, such as U.S. EPA, the National Cancer Institute, and the National Institute for Environmental Health Sciences, launched substantial initiatives of their own that provided additional support for research on a variety of health topics, and each contemplated that hired farm workers were a suitable group for study. Nevertheless, NIOSH continues to provide the lion’s share of support for research on this population.

Private foundations and some state agencies have also contributed to this new direction in medical research. Of special note in this regard are the efforts of the California Endowment, a large, private foundation that supports initiatives that directly serve the health care needs of Californian residents.

In retrospect, it is fair to say that the 1990 Agricultural Initiative of NIOSH was, and remains, the largest and broadest of these efforts, and has resulted in more financial support for research on hired farm worker health and safety than was provided by Federal funds in all previous years combined. Perhaps because of this substantial level of financial commitment, the NIOSH initiative succeeded in attracting a number of highly capable medical researchers to the study of this population.

The National Agricultural Workers Survey (NAWS) served as a reference standard to which discussions of surveys of hired farm workers by NIOSH-funded researchers usually turned. NAWS was quickly realized to be ‘state-of-the-art’ in farm labor studies by epidemiologists who working on agricultural health and safety. Indeed, Dr. Richard Mines was invited to speak at the 3rd International Symposium on Agricultural Medicine precisely because many NIOSH-funded researchers and others who were newly involved in the study of hired farm workers wanted to learn as much as possible about NAWS. In recent years, NIOSH has partnered with NAWS, and Dr. Sherry Baron will present some of the findings resulting from that collaboration. Dr. Daniel Carroll brings to NAWS the necessary background in epidemiological research that promises to further strengthen this collaborative work with NIOSH.

The California Hired Farm Worker Health Needs Assessment

The California Endowment awarded a major grant in October 1998 to the California Institute for Rural Studies to conduct a Health Needs Assessment (HNA) of the hired farm worker population of the state. This award had several goals:

Develop a health needs assessment based on an accurate cross-section of current hired farm workers in California;
Provide, for the first time, reliable and current baseline data which can serve to objectively identify priorities for interventions funded by The California Endowment;
Provide baseline data that can serve as a reference against which to measure the effectiveness of both public and private interventions.

A key feature of the HNA is that it was to include a comprehensive physical examination to be administered by third-party medical personnel, ideally at a local clinic that has experience serving hired farm workers. The physical examination that was contemplated would include a full blood workup at a medical laboratory and possibly other lab work as well.

Finally, the HNA was to be large-scale and population-based, involving an approximate total of 1,000 subjects from communities throughout the state. Selection of the communities would be such that each of California’s six agricultural regions would be represented. The intent was to construct a sample that would approximate a cross-section of the full population of current hired farm workers.

Health Needs Assessment: Community Participation

The first step in developing the California Hired Farm Worker Health Needs Assessment was to obtain significant advice regarding the design of the project directly from current hired farm workers. A Farm Worker Advisory Committee composed of eight such persons (four men, four women) was recruited during October 1998, with the assistance of CIRS staff and local collaborators Esther and Jorge Villalobos. A stipulation imposed by CIRS was that those who were recruited for this purpose should have no formal relationship with farm worker advocacy organizations, labor unions or service providers.

Three meetings with the Farm Worker Advisory Committee were held in the nearby community of Winters, at Catholic Church facility, during Autumn and Winter, 1998-99. Committee members were paid an honorarium in consideration of their time and of travel expenses to attend. Meetings were held on weekday evenings and generally were two to three hours duration. The meetings were conducted in Spanish. Project PI Villarejo participated in all three meetings as did key CIRS staff, and one of the project co-investigators (Bade) participated in one of the committee meetings.

All committee members were unaware of The California Endowment and requested that CIRS provide basic information about that organization and its motives in sponsoring this project. The committee also requested a direct meeting with the foundation staff.

CIRS staff explained the goals of the HNA and responded to questions from committee members about how the information that was gathered was going to be used. CIRS staff asked the committee members for advice about how the HNA should be designed. In particular, questions were raised about how to structure the project to insure a high level of participation, including whether potential subjects would be willing to undergo a complete physical examination.

The advisory committee was generally supportive of the concept of the HNA, and was enthusiastic about the thoroughness of the physical examination that would be provided at no cost to all participants. Also, it was agreed that a $30 honorarium to be paid to HNA subjects was appropriate in view of the time commitment and possible inconvenience that would be required of subjects.

In a surprising development, the committee argued that all subjects should be provided with free medical treatment for any and all health problems disclosed by the physical examination, and asked CIRS to present this request to the sponsoring foundation. Several committee members pointed out that few farm workers have any form of health insurance, and that if people learned of adverse health conditions as a result of participation in the HNA, they should be entitled to free and complete treatment. After some discussion, CIRS agreed to present this request, and the request for a direct meeting, to the foundation staff.

Ultimately, after discussion with foundation staff, it was necessary to report back to the committee that neither request could be met. However, the committee was provided assurance that medical personnel would meet individually with each subject to review the findings of the physical examination, and that referrals would be provided for treatment of conditions disclosed by the exam. CIRS staff also explained that local clinics would be used to conduct the physical examinations and that these clinics would likely assume responsibility for providing reviews of the exam results and would also likely be able to provide treatment, when it was needed.

Also discussed at length was the planned dwelling enumeration that would be undertaken in each community. A major concern was the definition of ‘household’ to be used in the survey. The committee was already familiar with the issues involved when multiple families shared living quarters and advised CIRS to base the ‘household’ definition on family, especially since many hired farm workers regularly send remittances back to family members in Mexico. It was agreed that a ‘household’ consists of all persons who share all expenses for rent, clothing, food and medicines.

At the third and final meeting of the committee, a group photograph was taken, that was used to accompany an article about the project that was prepared by Jorge Villalobos and printed in the local newspaper, The Winters Express. Photocopies of this article and the photograph were subsequently used to introduce the project to a variety of communities and agencies.

At the conclusion of the Farm Worker Advisory Committee process, CIRS staff asked committee members if any would be willing to complete a ‘pilot’ interview, and to provide detailed review of the questions in the survey instrument. Two committee members volunteered to do so and, several months later, after the survey instrument was prepared, fully cooperated in completing ‘pilot’ interviews and provided feedback on its contents and wording.

Health Needs Assessment: Sampling Procedures

A community-based, household survey was the sampling method adopted for the California Hired Farm Worker Health Needs Assessment (HNA). The main advantage of this approach is that a complete enumeration of all dwelling units within a given geographic area is functionally equivalent to an enumeration of all persons residing within the same area since everyone who resides there necessarily sleeps in some type of dwelling unit. Note that for this purpose a ‘dwelling unit’ may be of any type: house, apartment, trailer, motor home, tool shed, garage, tent, vehicle or a temporary shelter. This sampling method seeks to approach potential subjects at their place of residence instead of the workplace. The household survey method employed in the HNA was developed and utilized in the Parlier survey conducted eight years earlier (Sherman et al, 1997).

The criteria for subject eligibility was the following: age 18 years or older, and employment as a hired farm worker for any length time within the twelve-month period prior to contact by the HNA. Persons who meet these qualifications but who are injured and unable to work at the time of the survey are eligible for inclusion. Also, there were no restrictions imposed on the type of hired farm work the individual may have performed. Dairy, poultry and other types of livestock work were considered to qualify along with any type of crop farm work.

These criteria for qualification of subjects differ somewhat from those used by the NAWS, mainly in that the HNA is a household survey whereas NAWS is employer-based, and any type of hired farm work is considered appropriate for the HNA whereas NAWS limits itself to ‘perishable crop agriculture.’ Also, NAWS includes any person aged 14 or over, whereas HNA is limited to persons age 18 or older.

A multi-stage sampling strategy was developed to identify potential subjects for participation in the California Hired Farm Worker Health Needs Assessment. The underlying philosophy of the sampling strategy was to ensure that all, or very nearly all, persons who would qualify as hired farm workers at the time of the survey have a known chance of being selected for possible participation in the health needs assessment.

The first stage of the sampling strategy involved adopting the assignment of each of the state’s fifty-eight counties to one of six agricultural regions, following the definitions utilized by the California Department of Employment Development. These regions are: Central Coast, Desert, North Coast, Sacramento Valley, San Joaquin Valley, and South Coast (see map and accompanying list of counties per region).

Within each region, all Medical Service Study Areas (MSSA), defined by the California Office of Health Planning and Research, were enumerated and ranked. An MSSA is a geographic unit within which most residents obtain nearly all of their needed health care services. Each MSSA is comprised of a number of Census Tracts, which are defined by the U.S. Census Bureau. Since there are 487 MSSA and roughly 6,000 Census Tracts within California, there are an average of about twelve tracts per MSSA, each containing, on average, about 60,000 persons.

The usefulness of MSSA data for examining access to health care services in communities that have a high proportion of hired farm workers has been previously reported (Villarejo, 1999). For purposes of the HNA, MSSA data that was obtained from the California Department of Health Services were supplemented by additional data items obtained from the 1990 Census of Population and Housing. Specifically, total employment and farm employment data were obtained for each tract, and subtotals for these items were added to the data file for each of the state’s MSSA.

Rankings of all MSSA within each region were based on two factors: the fraction of each MSSA’s total employment accounted for by farm employment, and, second, each MSSA’s share of total regional farm employment. Two dimensional scatter plots based on these factors were constructed for each region that displayed the values for these two factors for each MSSA.

The second stage of sampling involved selecting a number of MSSA within each region for which the factors that measure farm employment were deemed sufficiently large as compared with other MSSA within the same region (the specific criteria were agricultural employment of at least 5% of MSSA employment, and amounting to at least 2% of regional agricultural employment). To illustrate, for the Desert Region, census data indicated that MSSA #128 (located in south-central Riverside County) had 50.9% of its total employment in the agricultural sector, and it also accounted for 8.9% of total farm employment for the entire three-county Desert region. No other MSSA of the Desert Region had a level of agricultural employment as high as 28% of total employment, and the one MSSA that was closest had less than 1.5% of the region’s farm employment. Clearly, this ranking scheme separates and identifies those MSSA whose farm employment is both locally important as well as regionally significant. It is this combination of factors that was used for selecting communities for potential sites for the health needs assessment of hired farm workers in California.

Using this procedure, twenty-four MSSA were selected as candidates for choosing community sites for the health needs assessment. Each of the six regions was represented, as were fourteen counties and an aggregate total of 164 Census Tracts.

The third stage of sampling involved ranking the selected census tracts within each region according to the two factors used to rank the MSSA (described above). A subset of census tracts in each region was selected for which the combined factors were found to be sufficiently large. Ultimately, 58 Census Tracts were deemed to be suitable candidates using this criterion.

Each census tract was then weighted by the number of persons reported by the Census to be employed in agriculture, and a random selection of one tract was made for each of five of the state’s six agricultural regions. Excel’s random number function was used for this purpose. A sixth site was purposefully selected to represent the Desert Region based on feasibility considerations. The community of Mecca was chosen to represent the Desert region because of the presence of a federally-funded migrant clinic willing to provide the needed physical examinations, and because the community is both relatively small and geographically isolated.

A seventh site was purposefully selected to provide a second community to represent the San Joaquin Valley. This was done because a very large share of the state’s hired farm worker employment is located in the valley (EDD reports that about 50% of all California hired farm worker employment is located in the valley), and it was thought that two San Joaquin Valley sites would be more representative of this large and diverse region than just one. The second San Joaquin Valley community was purposefully chosen to represent a different county than the one where the randomly selected site was located, and, as well, to be located on the opposite side of the Valley (West vs. East). These considerations for selecting the second San Joaquin Valley site were also prompted by a desire to seek a diverse range of farm tasks represented among the work experience of subjects, as reflected in the differences in cropping found on the two sides of the Valley (tree fruit, raisin grapes, and livestock farms on the East side vs. cotton, alfalfa, vegetables and melons on the West side).

The fourth stage of sampling involved mapping all dwelling units located within a selected census geographic sub-unit. In the case of Mecca, for example, this meant precisely identifying the location of every dwelling unit, no matter how unconventional, in a 40 square mile area that included both the town (about 1.5 sq. mi.) and surrounding countryside. Dwelling units were assigned unique identification numbers, and randomly selected dwelling units were listed, in order, for personal visits by interviewers.

Dwelling units were also classified within three strata according to whether they are Permanent dwellings with a permanent street address and recognized for assessment purposes by the County Assessor (usually houses or apartments), Temporary dwellings lacking a permanent street address and not recognized as dwellings by the County Assessor (sheds, garages, motor homes, trailers, tents, or vehicles), and Labor Camp dwellings that are self-identified as such by residents. Separate random draws of dwellings from each of the three strata were conducted to insure proportionate representation of residents of these different types of dwellings.

Contacts with residents of dwelling units were made in approximate sequential order of the random selection until the desired number of qualifying subjects was secured. Each of the seven communities was assigned a ‘target’ number of subjects, based on the corresponding regional share of reported annual average hired farm worker employment. The target number of subjects per agricultural region was based on the regional share of annual average hired farm worker employment reported by the California Department of Employment Development in its 1999 Agricultural Bulletin. Table 2 summarizes the HNA sites, each region’s share of annual average hired farm worker employment, and the corresponding regional share of HNA subjects actually obtained in the project.

Table 2. HNA Sites, by Region, and Share of Numbers of Subjects

Region Ag Employment Community Site HNA Subjects
Central Coast 14% Gonzales 15%

Desert 9% Mecca 12%

North Coast 4% Calistoga 3%

Sacramento Valley 16% Arbuckle 13%

San Joaquin Valley 50% Cutler, Firebaugh 47%

South Coast 7% Vista 9%

Source: Agricultural Employment data for 1999 are based on 12-month averages for the six regions as reported in Agricultural Bulletin, Employment Development Department, State of California.

Randomly selected dwellings were contacted by project interviewers. If at least one individual age 18 or older resided there who had performed hired farm work in the previous twelve months, then all eligible residents of the dwelling were enumerated. The Dwelling Enumeration was structured such that only residents age 18 years or older who had worked as hired farm workers for any duration during the previous twelve months were listed. Women were listed first in descending order of age, and men were listed next, again in descending order of age. Specially prepared lottery tables were prepared in advance for this purpose. The sealed envelope containing the lottery table for the dwelling was opened in the presence of residents and the randomly selected individual was then asked to be a participant in the health needs assessment.

One of the concerns of the investigators was to include a large enough sample of women to ensure the validity of findings of gender-specific health outcomes. For this reason, women were deliberately over-sampled in the process described above. However, the Dwelling Enumeration procedure provides an accurate determination of the ratio of eligible male and female persons within each community site. Thus, the extent of over-sampling of females can be accurately calculated.

A full-disclosure Human Subject Permission form was presented to subjects and read aloud to them in their preferred language. If the subject agreed to participate, a signature was requested and the interviewer proceeded with the main interview.

The main interview required roughly one and one-half hours and was followed by a scheduled visit to a nearby clinic or other site where both the physical exam and a second, shorter duration interview was completed. Participants were offered the free medical examination, free transportation to and from the examination, a follow-up consultation to explain the results of the physical examination, and a $30 cash payment in consideration of their time. Appointments for the physical examination were scheduled so that they would not conflict with the subject’s work hours. Often, this meant scheduling evening or weekend appointments.

The entire set of survey materials and proposed procedures were submitted for peer review to the Human Subjects Committee of the University of California, Davis. This review was not only required by the two project collaborators who are affiliated with UC, but also was strongly favored by CIRS in order to obtain oversight of the project by leading professionals.

Health Needs Assessment: Survey Instruments

The HNA had three principal components: main survey instrument, physical examination, risk survey instrument. The first instrument was administered in the subject’s residence, usually at the time of first contact by the interviewer. The physical examination and risk survey instrument were administered at the time of the agreed-upon appointment, usually within a clinic or other medical facility. Each required about twenty to thirty minutes to complete.

The main survey instrument borrowed generously from the NAWS, and included a household grid and work grid that are essentially identical to those found in the NAWS. A significant number of questions were deliberately worded to be identical with the NAWS, the better to facilitate direct comparisons of findings from the HNA with those of the NAWS. On the other hand, the HNA instrument includes lengthy sections on access to health care services, self-reported health conditions and doctor-reported health conditions. These comprise about 29 pages of the total of 70 pages of the instrument. Health-related data was requested not only about the subject but also for each member of the subject’s household. A departure from the NAWS is the extensive use of Census of Housing and Population (long form) questions relating to housing conditions in the HNA. Nearly all of these questions were directly copied from the Census and will facilitate direct comparison of HNA findings with those of the Census for each of the seven communities selected as HNA sites.

The structure of the main survey instrument is outlined in Table 3.

Table 3. Outline of Main Survey Instrument, Health Needs Assessment

Section Topics included

Household Composition Family enumeration, family member’s age, place of birth, education, current employment, farm employment

Personal Demographics Race, ethnicity, place of permanent residence, Spanish/English proficiency

Health Services Utilization Health insurance, cost, most recent visit to doctor, clinic, dentist, eye care provider, chiropractor, and traditional healer, use of home remedies

Self-reported Health Conditions Dental, respiratory, musculoskeletal, gastrointestinal, urinary, eye, ear, traumatic injuries, emotional illnesses, ethnospecific illnesses

Doctor-reported Health Conditions Tuberculosis, cancer, diabetes, hypertension, heart attack, anemia, arthritis/rheumatism, stroke/embolism, asthma, hepatitis, allergies, skin conditions, learning disabilities, neurological disorders

Work History Jobs in past twelve months, use of tools, transportation to job, employer provided health insurance, workers compensation insurance

Income and Living Conditions Personal and family income, housing conditions and costs, use of social services

Workplace Health Conditions Eye irritation, blurry or clouded vision, skin irritation, headache, dizziness, nausea or vomiting, numbness or tingling, diarrhea, dehydration

Protective Equipment & Training Use of protective equipment, safety training and certification under WPS, direct contact with pesticides and pesticide illness

Field Sanitation Toilets, drink water & disposable cups, wash water

Work Related Injuries Detailed profile of any injury while doing farm work or while traveling to and from farm work

Immigration Status Current status, program, Social Security card

The main survey instrument, referred to herein as Instrument A, was piloted in Mecca, the first site attempted in the HNA. Revisions, including substantial deletions, were then made, based on the experience in Mecca. The second version, Instrument B, was then utilized in portions of Firebaugh and Vista, and was again revised based on those experiences. The third version, Instrument C, was subsequently utilized in the remainder of Firebaugh and Vista, and all of Cutler, Gonzales, Arbuckle and Calistoga.

The revised instruments (“B” and “C”) were submitted, after use in the field, for review by the Human Subjects Committee of the University of California as an addendum to the initial review and approval. All project investigators were asked to complete a course on the subject of ethical issues in human subjects research and all did so.

Physical examinations were conducted by third-party medical staff who were under contract to CIRS. The original intent of the HNA was to have the physical examination conducted at local clinics that had a long history of serving hired farm workers. However, after the selection of the community sites, it was found that only one (Mecca) had a migrant clinic and just one was served by a community clinic located there (Vista). At the other extreme, Arbuckle had no medical service provider whatsoever, and the nearest clinic was a small, part-time operation located some distance away in Williams. Calistoga, Cutler and Gonzales were served by private physicians but were also served by community clinic satellite offices located in nearby communities (St. Helena, Dinuba and Soledad, respectively). In contrast, Firebaugh had several private physicians and a well-established private clinic with a long history of providing services to hired farm workers.

In the end, CIRS contracted with the community clinics in Dinuba and Vista, with the migrant clinic in Mecca, and with private clinics in Firebaugh and Gonzales. For Arbuckle and Calistoga, CIRS contracted directly with appropriate medical staff and set up “storefront” facilities devoted exclusively to providing the needed physical examinations.

In retrospect, it is fair to say that the different types of medical services available to hired farm workers in the seven community sites probably represents the range of facilities in rural and agricultural areas of California. Thus, the different experiences that CIRS found in working with these different types of health care providers reflects what hired farm workers have to deal with when they seek care. The lack of care in many such communities has been documented in another paper (Villarejo, 1999).

Laboratory work was provided, under contract with CIRS, by two commercial medical laboratories. One provided these services in six of the seven HNA communities, but did not serve Mecca. Therefore, for Mecca, a second commercial laboratory was contracted.

The physical examination component of the HNA comprised a relatively thorough examination. Dental, skin and breast examinations, as well as blood pressure, cholesterol, blood glucose, hemoglobin, PAP smear, STD screening, and full blood workup (CBC panel) were to be included.

Initially, it was intended to include tuberculosis screening as well because of the suspected relatively high prevalence of this disease in the hired farm worker population. However, despite the fact that TB is a reportable communicable disease, it proved impossible to make satisfactory arrangements for referral of subjects, should that be required. The planned TB screening had to be abandoned. In Mecca, the first community where the HNA was undertaken, chest x-ray facilities were not available. Thus, if a subject was found to have a positive PPD, which requires the subject to have a chest x-ray to determine if active tuberculosis is present, he/she would have to travel to another community. Moreover, it was determined that the nearest public facility offering this service was in Moreno Valley, some 75 miles away. The community of Indio, much closer to Mecca, had a private hospital that could offer the service, but subjects needing a chest x-ray would have to pay out-of-pocket for its cost. After careful review, it was decided to abandon the tuberculosis screening.

Table 4 provides a comprehensive overview of the components of the physical examination offered to HNA subjects.

Table 4. Components of Physical Examination, Health Needs Assessment

Component Description

Biometric Height, weight, blood pressure

Dental Teeth, gums, caries, broken/missing teeth, impacted

wisdom teeth, gingivitis

Skin Lesions, dermatitis, pre-cancerous growths

Body Palpation, respiratory function, breast examination

Screening Cholesterol, blood glucose, PAP smear, STDs

Blood chemistry Full CBC panel

Medical history Illnesses, immunization, family history

At the time and place of the physical examination, a second instrument was administered, usually described as the “risk behavior questionnaire.” This survey covered all forms of risk behaviors: tobacco, alcohol, drugs, sexual behaviors, domestic violence, and workplace violence. Because many of the questions were of a highly personal nature, it was thought that the privacy of a medical facility would be conducive to obtaining full cooperation from the subjects. For that reason, all types of questions relating to these behaviors were separated from the main instrument and included in this one.

To ensure confidentiality of the risk behavior interview, only the subject’s ID number was coded onto the face of the instrument. The administration of this instrument was problematic in the early phases of the project. Initially, medical assistants at the facility where the physical examination was conducted were asked to carry out this work. When this procedure was discovered to have undesirable results in some cases, HNA project staff members, including former a Mexican priest, were assigned to conduct these interviews.

Separate instruments were developed for male and female subjects, to reflect their different biological structures. Table 5 describes the main subject areas of the risk behavior instrument.

Table 5. Risk behavior instrument, Health Needs Assessment

Section Topics included

Reproductive Health (female only) Menstruation, pregnancies, births

Health Habits Tobacco, alcohol

Threats and Violence Workplace and domestic violence

Sexual Behaviors Partners, STDs, safe sex practices
Drug Use Extent of use, type of drugs, intravenous drug use

Mental & Psychological Illness Mental health history, treatment

Workplace Risks Workplace alcohol use, workplace injury, treatment and workers compensation, use of raiteros

Health Needs Assessment: Results

Field research began in March 1999 and was completed in December 1999. The project design contemplated beginning the work in Mecca, the Desert site, in the spring season when employment there reaches an annual peak. Since Mecca was also the “pilot” for the project, all aspects of the work there were subject to intensive review. As a result of this review, changes were made in the main survey instrument, and experienced project staff replaced clinic staff to administer the risk behavior questionnaire in the other six sites.

Following the conclusion of work in Mecca, interviews began in the Vista and Firebaugh sites. Later, as the summer progressed, the Gonzales and Arbuckle sites became the focus of the project. Finally, during the autumn season, the Cutler and Calistoga sites were completed. During the late summer, interviews were simultaneously underway at three sites.

Some 11,876 dwellings were enumerated in the seven communities, and about 2,454 randomly selected dwellings were contacted or sought out. Hence, the overall sampling fraction in the seven communities was 20%, meaning that, on average, one in five dwellings was actually contacted in person. The sampling fraction varied considerably from community to community, and was as high as 45% in Cutler but as low as 13% in Calistoga.

The enumeration of dwellings presented some unusual challenges that were specific to particular sites. In Mecca, for example, several dozen vehicles that parked each night in the few parking lots in town, or on the street, were “home” to the workers who inhabited them. Since these “dwellings” were not stationary, but were relatively few in number, separate enumerations and random sampling was done on several successive evenings. Interviews for this group of workers were separately identified since they were not drawn following the standard protocol.

Calistoga presented a different challenge: hired farm workers were found to be living in dwellings located in just a couple of blocks on one end of town. For nearly all of the city of Calistoga, random selection of ten dwellings per block turned up no hired farm workers, and such blocks were then stricken from the list of areas to be sampled. Overall, just 16% of Calistoga dwellings sampled had eligible persons residing there.

In Vista, most hired farm workers were found to be living in a relatively few extremely large apartment complexes. Slightly more than 10% of dwellings sampled in Vista using the standard protocol were found to be residences for eligible persons. It was also found that there were groups of workers who assembled each morning at “pick-up points” along key intersections in town. After some review, it was decided to add to the Vista sample portions drawn from both the large apartment complexes in a systematic fashion (alternate numbered apartments were sampled) and also from the groups found at pick-up points. Both of these sub-groups were separately identified since they were not drawn following the standard protocol.

In all seven communities, an aggregate total of 2,082 eligible hired farm workers were recorded in the Dwelling Enumeration process. Using the lottery table process, 1,165 individuals were asked to participate in the health needs assessment. This is the HNA sample. Of these, 965 agreed to cooperate. Thus, the overall participation rate was 83%, which is a quite satisfactory response. Health information was gathered for a total of 3,013 persons, representing the 965 subjects and 2,048 household members.

An additional 1,300 individuals also resided in these same dwellings but were not considered ‘household members’ by the selected subject. For these additional persons, only very limited data was gathered: whether they were children or adults, whether they worked in agriculture, other types of employment or were not working. If they were age 18 years or older and worked as hired farm workers, their age and gender was also recorded.

One of the unusual aspects of the HNA is that it is also a housing survey. By using a rigorous enumeration and sampling procedure, important information about housing conditions was determined. Vacancy rates were found to be extremely low in these communities, averaging just 4.2% among conventional housing units. However, the vacancy rate was found to be far below this average in several communities: Gonzales, 1.3%; Mecca, 1.7%; Cutler, 2.4%. It is fair to say that these communities have a severe shortage of available housing. This finding is certainly related to the finding that two of them (Cutler and Mecca) have substantial numbers of temporary housing or labor camps, including informal structures that house significant numbers of workers.

In Mecca, it was found that there were more temporary and labor camp dwellings than permanent dwellings (915 vs. 829). While about 60% of permanent dwellings in that community provided residence for hired farm workers, more than 80% of temporary dwellings were farm worker homes.

Just 33 subjects preferred to complete the main instrument in English, and the remaining 932 preferred Spanish. However, a few subjects spoke an indigenous dialect and a bi-lingual (Spanish/Mixteco) interviewer was employed to complete these interviews. Thus, over 96% of the interviews were conducted in Spanish.

About two-thirds of the subjects who completed the main survey instrument also participated in the physical examination and risk behavior questionnaire (N=668). Thus, the overall participation rate for the HNA was 57.3%. Table 6 summarizes the participation for each community site and for the project as a whole.

Table 6. Participation rate, Health Needs Assessment

Field Site Locations

Total Number of Interviews

Total Number of Physical Exams

Total Refusals

Participation Rate for Survey

Participation Rate for Physical Exam

Number of Female Interviews

Number of Male Interviews

Number of Female Physical Exams

Number of Male Physical Exams

Physical Exam Participation Rate: Men

Physical Exam Participation Rate: Women

Preliminary physical exam data have been reviewed for the full sample. Though the results will have to be properly weighted for purposes of comparison with other populations, the physical exams turned up some findings that are a cause for concern. As regards dental, one-third of the sample had decayed teeth, one-third had missing or broken teeth, and one-seventh had gingivitis.

Roughly one person in eight had a cholesterol level above 240 mg/dl. Hemoglobin levels were below 14 mg/dl for one-third of the sample, which indicates that anemia could be a significant problem. And one in twelve had hypertension (diastolic above 90, systolic above 140). Blood glucose levels were above 115 mg/dl for one out of every four persons, suggesting that fasting blood glucose measurements should be recommended for them.

Some 18.5% reported having had a workplace injury at some point in their farm work career that was compensated under the California Workers Compensation Insurance system. But just 64% said that had not had such an injury, and the other 17.4% did not answer the question, possibly because they were unaware that they were entitled to this insurance coverage.

About 7% of men said that a doctor had told them they had an STD, but none said they had been told they had HIV/AIDS. Among women, those who said a doctor had told them they had an STD was far lower, and none had been told they had HIV/AIDS.

A more complete analysis has been carried out for the Cutler portion of the sample. Basic demographic findings are outlined in Table 7 (below).

Table 7. A Profile of Hired Farm Workers, Cutler, 1999, N=188

Age Median age is 31
Gender Two-thirds male, one-third female

Birthplace 90% foreign-born (Mexico and Central America)

Marital status Four in ten are married; four in ten are single

Immigration status 49% undocumented; 28% legal permanent residents

Educational attainment Majority have less than 6 years of formal education

Income Median family income is $7,500 - $9,999 per year

Literacy status Less than half say they can read Spanish well

Only 6% say they can read English well

Farm work experience One-fourth began U.S. farm work in 1997 or later

This set of results is very similar with findings reported for California hired crop farm workers from the NAWS. Only the gender balance differs.

With regard to the Cutler sample, the health-related findings provide additional causes for concern. The sizeable numbers of persons who report never having been to a doctor or a health clinic is alarming. Even greater numbers report never having been to a dentist, which is certainly related to the poor dental health found in this population. Nevertheless, most of Cutler’s hired farm workers are in reasonably good health, which is likely related to the fact that they are rather young (median age of 31 among those 18 years of age or older). Table 8 summarizes the Cutler findings.

Table 8. A Profile of Hired Farm Workers, Cutler, 1999, N=188

Health insurance 69% report they have no health insurance at all;

Only 6% say their employer offers health insurance

Medical care utilization Half of the men have never been to a doctor;

But just 20% of women have never been to a doctor

Dental care utilization Half of women and three-quarters of men have never been to a dentist

Eye care utilization 80% of men and women have never had an eye examination

Physical exam results At least one-fourth have broken or missing teeth, decayed teeth, or impacted wisdom teeth;

22% of men (age adjusted) have elevated cholesterol levels (above 239);

78% of men and 88% of women (age adjusted) are overweight (body mass index greater than 25);

Few say they have STDs; none say they have AIDS/HIV;

One-fifth have at least two of the following four clinical risk factors for diabetes (hypertension, obesity, low HDL, elevated triglycerides);

Work conditions Only one-third say they have ever received pesticide safety training; just one-seventh say they have received a WPS certification card;

One-third say they have Workers Compensation Insurance protection at the job, two-thirds say they don’t;

Half say they pay their employer or contratista for a ride to their farm job;

94% say their employer provides drink water and disposable cups at the job everyday;

95% say their employer provides toilets at the job everyday;

The main findings are that Cutler residents who are hired farm workers are mostly young, Mexican men, who rarely use health care services. Most are in good health, but are severely lacking in preventive care, especially dental and vision care. As a result of the lack of preventive care, about one-third have serious dental problems, as discovered in a physical examination in conjunction with the survey. Few have health insurance, and even fewer have employers who offer health insurance. The lack of preventive care is related to the fact that most hired farm workers who reside in Cutler have extremely low family incomes, most commonly in the range of $7,500 - $9,999 per year. In addition, a plurality are undocumented and rarely apply for or use needs-based government services.

A finding that is of some concern is that male workers were less responsive to the physical examination than were women, a difference of about 14% in Cutler, and about 5% overall in the seven communities. Considering the fact that by failing to cooperate with the physical exam, for which free transportation was provided, they also gave up a $30 honorarium, there is likely to be a real gap in health awareness among men.

The HNA findings are, in most respects, quite consistent with the California NAWS findings. Since the HNA used a completely different sampling methodology and survey protocol, this is independent evidence supporting the reliability of the NAWS.

The HNA also demonstrates that hired farm workers are willing to cooperate with serious investigations of their health and workplace safety conditions, and are even willing to undergo extensive physical examinations that include a blood draw. It seems obvious that NAWS should consider adding a physical examination regime to the national survey.


Mobed, K., Gold, EB, Schenker, MB: Occupational health problems among migrant and seasonal farm workers. In Cross Cultural Medicine: A Decade Later (Special Edition). West J. Med. 157:367-373, 1992.

Sherman, J, Villarejo, D, Garcia, A, et al: Finding Invisible Farm Workers: The Parlier Survey, California Institute for Rural Studies, Davis, CA, 44 pp., 1997.

Villarejo, D: Health care among California’s hired farm workers. In Expansion of Health Care to the Working Poor, California Policy Research Center, University of California, Berkeley, CA. pp. 51-76, 1999.

Villarejo, D and Baron, S: The occupational health status of hired farm workers. In Occupational Medicine: State of the Art Reviews (Special Edition). 14:3, 613-635, 1999.