Document Type


Date of Degree

Summer 2012

Degree Name

PhD (Doctor of Philosophy)

Degree In


First Advisor

Moorhead, Sue

First Committee Member

Rautianinen, Risto

Second Committee Member

Specht, Janet

Third Committee Member

DeCook, Rhonda

Fourth Committee Member

Swanson, Elizabeth


This descriptive and analytic study used a secondary data set to describe and compare medication use and agricultural injury experiences between younger (≤54 years old) and older (≥55 years old) farmers; and to examine the relationship between the use of specific classes of medication and reported agricultural injury. The study sample included a total of 316 farmers, age 26 to 80 years old; 103 older farmers (33%), and 210 younger farmers (66%). This cohort of farmers sustained a total of 318 nonfatal agricultural injuries.

No statistical difference was found in the mean number of injuries sustained by older and younger farmers. The injury rate for the whole cohort of farmers was 41.95 injuries/100 years; older farmers' injury rate was 38.35 injuries/100 person-years, while younger farmers' was 44.01 injuries/100 person-years. Older farmers were more likely to report taking a medication than the younger farmers (OR: 3.08; 95% CI: 1.94-4.92). Older farmers had statistically significant greater odds of reporting the use of several medication classes/subclasses than the younger farmers, including: hormones; cardiac medications such as: ACE inhibitors, blood pressure medications, alpha blockers, and beta blockers, and finally central nervous system medications such as pain medications. Older farmers were also found to report taking more medications than younger farmers.

Multiple logistic regression analysis using GEE was used to examine the association between using specific classes of medication and agricultural injury, taking into consideration a myriad of confounding factors. Agricultural work exposures associated with injury included noise (OR 1.39, 95% CI: 1.02-1.90), chemical/pesticide use (OR 1.88, 95% CI: 1.39-2.55), heavy lifting (1.55, 95% CI: 1.06-2.28) and raising livestock (OR 1.49, 95% CI: 1.08-2.06).

Medication classes significantly associated with an increased risk for agricultural injury included taking two different types of heart medications: beta blockers (OR 2.30, 95% CI: 1.07-4.97) and ACE inhibitors (OR 2.72, 95% CI: 1.15-6.46). Farmers taking a blood formation/coagulation medication were found to have less risk of injury (OR 0.50, 95% CI: 0.28-0.93) than those not on a blood formation/coagulation medication. When exploring the issue of polypharmacy, no medication interactions were found to be significant. Yet, the number of cardiac medications taken per quarter was found to be statistically significant. The odds of nonfatal agricultural injury were lower with the use of more than one cardiac medication (OR: 0.35, 95% CI: 0.13-.0.94) compared to a farmer taking no cardiac medications.

Health conditions related to agricultural injury included depression and several interaction terms between taking medication and general health status. Farmers reporting their depression level as medium had a lower risk for nonfatal agricultural injury (OR 0.71, 95% CI: 0.53-0.95) compared to farmers reporting their depression as being low. Finally, several interactions between taking medication and general health status were statistically significant. These interactions illuminate two trends: 1) farmers in excellent/very good/good health have lower odds of injury if they are not taking medication versus if they did take medication, and 2) farmers with poor health have decreased odds of injury if they took mediation versus if they did not take medication.

This research contributes to the limited knowledge base regarding medication use and agricultural injury by identifying classes and subclasses of medications that are associated with nonfatal agricultural injury, as well as identifying an important interaction between general health status and medication use in regards to nonfatal agricultural injury.


aging, agriculture, injury, medication use, older farmers


xiii, 222 pages


Includes bibliographical references (pages 211-222).


Copyright 2012 Michelle L. Umbarger-Mackey

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Nursing Commons