Our study  contributes to existing knowledge while adding some unique elements to the literature. In particular, our study has four key strengths. The first strength is the sample size, which is one of the largest in the literature. For this retrospective study, we used data from a sample of men aged 66 years and older with localized or advanced prostate cancer who were diagnosed between 1996 and 2003. Of the 154,089 men, 62,330 (average age 76 years) received ADT within 2 years of being diagnosed with cancer, and 91,759 did not receive the treatment.
Second is the length of follow-up. Each patient in our cohort was followed up until 2013, so each patient potentially had at least 10 years of follow-up after their diagnosis. To our knowledge, this is one of the longest follow-up periods – if not the longest – in the literature.
Third is the fact that we adjusted for several key covariates and performed important sensitivity analyses. We adjusted the measures of association for potential influential covariates, including sociodemographic characteristics, disease severity, and medical comorbidities. Our sensitivity analyses tested the robustness of our analysis by comparing groups across comorbidity, stage of cancer, and treatment.
Finally, we examined the associations across different doses of ADT and found that the association was stronger for men who received more doses of ADT.
- Jayadevappa R, Chhatre S, Malkowicz SB, et al. Association between androgen deprivation therapy use and diagnosis of dementia in men with prostate cancer. JAMA Network Open 2019; 2: e196562