Farmer Health Study

TIMELINE OF THE STUDY

1993

Farmers in the University of California, Davis Farmer Health Study, are defined as the person who made the day to day primary management decisions, whether they were the owner or a manager (referred to as the primary operator). They were chosen randomly from the California Agricultural Statistics Service (CASS) list of approximately 57,000 farms [defined as a location that produced $1,000 or more in sales in the previous year].

A total of 4,500 farms were randomly chosen, and 3773 (83.8%) contacted by telephone [ at least 12 attempts were made to reach each person on the list]. 2,422 were eligible for the study, and 1,947 completed a computer-assisted telephone interview (CATI) that lasted approximately 40 minutes. The cross-sectional survey focused on their demographics, commodities produced, farm practices, health symptoms and histories.

1995-1996

In 1995 a substudy was conducted which focused on respiratory disease and its association with farming tasks and allergies. Subjects were defined as having respiratory symptoms if they reported one or more of the following chronic respiratory symptoms in 1993: Chronic bronchitis [brought up phlegm on most days for 3 consecutive months or more during the year for 2 or more years]. Persistent wheeze [chest sounded wheezy or whistling most days or nights or chest sounded wheezy or whistling when they had a cold and occasionally apart from colds]. Chronic cough [coughed on most days for 3 consecutive months or more during the year for 2 or more years]. Of the farmers interviewed in 1993, 359 reported at least one of these 3 chronic respiratory symptoms. All the symptomatic farmers were selected for the study and nearly 50% of the 'normals' (703). Of these 266 of the 'cases' (with symptoms) and 511 'controls' (without symptoms) were interviewed by CATI. The interview contained sections questions about their respiratory and allergic symptoms, health conditions and farming tasks. Those living in the Central Valley (374) were visited in the field to measure their lung function, collect daily diaries which documented health symptoms to test for allergies.

1998

In 1998, the whole group was again surveyed by phone. Of the 1798 participants who had agreed in 1993 to further contact, 1,652 were located, 85 were deceased (5.1%), 60 (3.6%) too ill or hard of hearing - or unavailable in the time frame required (March to July 1998) and 158 (9.6%) refused to participate. The interview lasted 30 to 40 minutes, and a total of 1,349 completed the follow up interview. Topics covered included demographics, commodities grown, work activities, general health, smoking and drinking habits, injuries, musculo-skeletal exposures and conditions, respiratory exposures and conditions, atopy, dermatological conditions and functional abilities

2002-2003

A follow up study of the 374 Central Valley farmers tested in 1995/ 1996 was conducted in the winter of 2002/2003. Sixty-two farmers were selected--half of the group had below average lung function in 1995/1996 and they were paired with 'normals' by age and sex. Tests performed on the group included determination of lung function, lung volume, High Resolution Computed Tomography (HCRT) scans of lung structure and an interviewer administered questionnaire assessing respiratory health symptoms and exposures to a range of farming tasks, especially dusty ones.

2004

A third survey of the whole cohort of California Farmers was completed in 2004. The study was composed of 866 participants, with a return rate of 64% from the interview in 1998. Retired farmers composed of 26.7% of those interviewed. The Computer Assisted Telephone Interview followed a similar format to previous editions. The study team was interested in current and long term (entire historical farm work) exposures to different farming tasks and environmental conditions, and current health status and symptoms. The emphasis this time was less on acute health symptoms, and more on chronic conditions as arthritis, chronic breathing problems functional ability and general / mental health. The whole interview was conducted on the telephone, and took up to about 45 minutes to complete.

2005-2006

Currently we are examining correlations between chronic and acute illnesses that farmers develop and their occupational tasks and environments. We expect to publish on the topics of musculoskeletal problems, work ability, respiratory problems and condition of aging in farmers.

Western Center for Agricultural Health and Safety
Department of Public Health Sciences
School of Medicine & UC Davis Health System
University of California, Davis

This page was updated 14 February 2006, 11:39 AM.

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