title: Unit Nonresponse in a Population-Based Study of Prostate Cancer.
abstract: Low unit response rates can increase bias and compromise study validity. Response rates have continued to fall over the past decade despite all efforts to increase participation. Many factors have been linked to reduced response, yet relatively few studies have employed multivariate approaches to identify characteristics that differentiate respondents from nonrespondents since it is hard to collect information on the latter. We aimed to assess factors contributing to enrollment of prostate cancer (PCa) patients. We combined data from the North Carolina-Louisiana (LA) PCa Project's LA cohort, with additional sources such as US census tract and LA tumor registry data. We included specific analyses focusing on blacks, a group often identified as hard to enroll in health-related research. The ability to study the effect of Hurricane Katrina, which occurred amidst enrollment, as a potential determinant of nonresponse makes our study unique. Older age (≥ 70) for blacks (OR 0.65) and study phase with respect to Hurricane Katrina for both races (OR 0.59 for blacks, OR 0.48 for whites) were significant predictors of participation with lower odds. Neighborhood poverty for whites (OR 1.53) also was a significant predictor of participation, but with higher odds. Among blacks, residence in Orleans parish was associated with lower odds of participation (OR 0.33) before Katrina. The opposite occurred in whites, with lower odds (OR 0.43) after Katrina. Our results overall underscore the importance of tailoring enrollment approaches to specific target population characteristics to confront the challenges posed by nonresponse. Our results also show that recruitment-related factors may change when outside forces bring major alterations to a population's environment and demographics.
authors.affiliation: Biostatistics Program, LSUHSC School of Public Health, New Orleans, Louisiana, United States of America.
authors.forename: Evrim
authors.identifier: http://orcid.org/0000-0003-2976-0778
authors.initials: E
authors.lastname: Oral
authors.affiliation: Consultant Epidemiologist, New Orleans, Louisiana, United States of America.
authors.forename: Neal
authors.initials: N
authors.lastname: Simonsen
authors.affiliation: Health Policy and Systems Management Program, LSUHSC School of Public Health, New Orleans, Louisiana, United States of America.
authors.forename: Christine
authors.initials: C
authors.lastname: Brennan
authors.affiliation: Department of Mathematical Sciences, McNeese State University, Lake Charles, Louisiana, United States of America.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Berken
authors.affiliation: Department of Epidemiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America.
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Su
authors.affiliation: Department of Urology, Roswell Park Cancer Institute, Buffalo, NY, United States of America.|Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: James L
authors.initials: JL
authors.lastname: Mohler
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: Jeannette T
authors.initials: JT
authors.lastname: Bensen
authors.affiliation: Epidemiology Program, LSUHSC School of Public Health, New Orleans, Louisiana, United States of America.
authors.forename: Elizabeth T H
authors.initials: ET
authors.lastname: Fontham
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology; D000328:Adult; D000368:Aged; D015982:Bias; D015340:Epidemiologic Research Design; D006801:Humans; D008145:Louisiana / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009657:North Carolina / Q000453:epidemiology; D010358:Patient Participation / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology; D011795:Surveys and Questionnaires; D016019:Survival Analysis