Document Type


Date of Degree


Degree Name

PhD (Doctor of Philosophy)

Degree In


First Advisor

Chrischilles, Elizabeth A


We sought increased understanding of men's decision-making process for prostate-specific antigen (PSA) screening, especially among elderly men, and a more knowledgeable basis for interventions to modify screening rates.

A cross-sectional postal questionnaire assessed measures consistent with the Theory of Planned Behavior among a population-based age-stratified random sample of 452 Iowa men who were free of prostate cancer and aware of PSA. Our primary outcome was intention to receive PSA screening within a year; this encompassed the degree men wanted and planned to be screened. We examined three explanatory variables via structural equation modeling: attitude, social influence, and perceived control. Attitude included the degree screening is important-unnecessary, reassuring-worrisome, and useful-useless. Social influence encompassed the extent a man believed people expect him to, and think he should be screened. Perceived control covered the degree a man can be screened, if desired, and how much control he has over screening. We then examined attitude, social influence, and perceived control as dependent variables. We examined how potential outcomes of screening influenced attitude, how specific people affected overall social influence, and how specific factors influenced perceived control.

Roughly 75% expressed intent to receive PSA screening within a year. Attitude, social influence, and perceived control each contributed significantly to the explanation of intentions (p<0.001); the model accounted for 72% of the variability in intention. Detecting cancer early, obtaining peace of mind, knowing their PSA value, and false test results were potential outcomes and each convincingly influenced attitude. A man's wife, primary care physician, urologist, family, friends, and people with cancer each visibly swayed overall perceived social influence. The impacts of health insurance, transportation, information, health problems, including PSA in routine exams, and primary care physicians on perceived control was less clear. Elderly men were unaware of the PSA controversy and believed physicians recommend screening men their age.

Our results suggest potential strategies to modify screening rates that include messages to modify men's attitudes about PSA screening and messages that target socially influential people. Being uninformed appears to be an important problem among elderly men who receive PSA screening.


prostate-specific antigen, decision making


xi, 282 pages


Includes bibliographical references (pages 272-282).


Copyright 2007 Daniel J Gregory

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