Quantifying the magnitude and potential influence of missing data in campus sexual assault surveys: A systematic review of surveys, 2010–2016

ABSTRACT

Objective: To understand how missing data may influence conclusions drawn from campus sexual assault surveys. Methods: We systematically reviewed 40 surveys from 2010–2016. We constructed a pseudo-population of the total population targeted across schools, creating records proportional to the respective response rate and reported sexual assault prevalence. We simulated the effects of 9 scenarios where the sexual assault prevalence among nonresponders differed from that of responders. Results: The surveys represented a total female undergraduate population of 317,387 with only 77,966 (24.6%) survey responses. Among responders, 20.4% reported experiences of sexual assault. However, prevalence of sexual assault could theoretically range from 5.0 to 80.4% under extreme assumptions about prevalence in nonresponders. Smaller, but still significant differences were observed with less extreme assumptions. Conclusions: Missing data are widespread in campus sexual assault surveys. Conclusions drawn from these incomplete data are highly sensitive to assumptions about the sexual assault prevalence among nonresponders.

KEYWORDS:

• Campus sexual assault
• gender
• missing data
• response rates
• survey methodology

Authors' contributions:

MR conceived the study, conducted the primary analysis, and wrote the first draft of the manuscript, with input and important contributions by AT, ST, and DH. AT and ST conducted the systematic search and independently abstracted the data from the surveys. ML conducted additional sex-specific analyses. MR, AT, ST, ML, and DH contributed to the interpretation of the findings, critical review of the manuscript, and approval of the final manuscript as submitted.