RESUMEN
OBJECTIVE: The aim was to assess the real-world healthcare resource use and direct medical costs for metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone or enzalutamide, in whom chemotherapy is not yet indicated (pre-chemotherapy) or who had previously received docetaxel-based chemotherapy (post-chemotherapy), before commencing these medicines. METHODS: A retrospective cost analysis of mCRPC patients who commenced abiraterone or enzalutamide between 2012 and 2015 was conducted. Routinely collected datasets from the largest health board in Scotland and the UK, Greater Glasgow and Clyde, were linked. They contained information on patient demographics, diagnosis, outpatient consultations, hospital admissions, treatments (abiraterone and enzalutamide), and supportive medicines. Unit costs were obtained from the Scottish Health Service Costs, Personal Social Services Research Unit, and British National Formulary. Generalised linear model-based regression was used to estimate total mean direct costs, and two-part models were used to estimate separate cost components. All models were adjusted for propensity score and key variables. Sensitivity analysis was conducted to explore the impact of hypothetical patient access scheme discounts. RESULTS: Estimated total mean direct medical costs of treating mCRPC patients were similar, albeit with wide and overlapping confidence intervals. Across both treatments, patients who received abiraterone or enzalutamide in a pre-chemotherapy setting incurred the highest total mean direct medical costs. However, post-chemotherapy patients were associated with higher outpatient clinic visits, inpatient hospital admissions, and supportive medicines. Regarding relative contribution to the total mean direct medical cost, the treatment costs were the main contributor, followed by inpatient admissions, outpatient clinic visits, and supportive medicines. CONCLUSION: The total mean direct medical costs were similar for abiraterone and enzalutamide patients. The costs were not driven by the choice of treatment regimen, but treatment setting (pre-chemotherapy or post-chemotherapy indications) and related healthcare resource utilisation. Future studies should focus on economic evaluations, such as cost-effectiveness analyses, using real-world data.
RESUMEN
Age-related decrease in testosterone levels is a potential risk factor for cognitive decline in older men. However, observational studies and clinical trials have reported inconsistent results on the effects of testosterone on individual cognitive domains. Null findings may be attributed to factors that studies have yet to consider. In particular, individual variations in polyglutamine (CAG) length in the androgen receptor (AR) gene could alter androgenic activity in brain regions associated with cognitive processes including memory and executive functions. However, the role of AR CAG repeat length as a moderator of the relationship between testosterone levels and cognition has not been investigated. Therefore, we aimed to examine the relationship between baseline calculated free testosterone (cFT) levels, change in cFT levels over 18 months and CAG repeat length on cognitive performance in memory, executive function, language, attention and processing speed domains. These relationships were examined in 304 cognitively normal older male participants of the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing. In the attention and processing speed domain, a short CAG repeat length appears to exacerbate the effects of low baseline cFT levels that are also lower than expected at follow-up. These results highlight that individual variations in AR CAG repeat length should be considered in future studies and clinical trials that examine the complex relationship between testosterone and cognition.
