Secondary Prevention of Anal Cancer among Men living with HIV: Acceptability and Suitability of Anal Pap Cytology and HPV DNA Type Testing

The risk of anal cancer is magnitudes higher among men living HIV than the general population. To contribute to an evidence-base in support of anal cancer screening guidelines, this dissertation evaluates the acceptability of screening among men living with HIV and sets the foundation for work examining the suitability of anal cytology and HPV DNA type testing for screening this population. A sample of 1677 men living with HIV enrolled in the Ontario HIV Treatment Network Cohort study completed a questionnaire module on HPV, its associated diseases, and their prevention in 2016-2017. Three objectives examined acceptability of anal cancer screening by 1) quantifying prevalence of screening, 2) examining the role of past screening on beliefs and willingness to be screened, and 3) evaluating facilitators to screening, HPV knowledge and self-perceived risk for anal cancer. In this sample, disparities in anal cancer screening were observed, wherein men from some racialized groups and heterosexual men were less likely to have discussed screening or to have been screened. The vast majority (90%) of men, however, were willing to undergo screening in the future. Positive beliefs regarding screening were associated with higher willingness. Behavioural intention does not ensure uptake, however, and factors such as health literacy and perceived susceptibility can influence men’s participation. Half of the study sample were unaware of HPV and the majority (73%) felt they had no or low chance of getting anal cancer. Specific risk-focused knowledge was associated with higher perceptions of risk. Findings will inform community-led health literacy efforts to improve participation in anal cancer screening. The final objective provides methodological guidance for the analysis of screening studies when verification of screening results is not possible for all participants. This simulation study assessed the utility of statistical methods to account for verification bias that arises in these scenarios. Findings suggest multiple imputation may be most suitable for handling complex missing data scenarios common to screening studies. This work will inform the analysis of data from a forthcoming anal cancer screening study to determine the best algorithm by which to screen for anal cancer among men living with HIV.Ph.D