BACKGROUND: Long-term post marketing surveillance studies are used routinely to monitor safety and to quantify the occurrence of safety outcomes among patients being treated with specific medications compared with similar patients with different or no treatment. Challenges to conducting traditional post-marketing surveillance studies for rare cancer outcomes include adequate case identification; exposure assessment; longitudinal follow-up; and sufficient study size.
OBJECTIVE: To describe the rationale and methods of two parallel post-marketing surveillance studies using claims databases and cancer registries to assess the risk of a rare outcome, osteosarcoma (OS).
METHODS/APPROACH: Study cohorts will be identified using the Medicare database (aged 65 and older) and Symphony Health Solutions’ (SHS) national outpatient pharmacy claims database (aged 18 years and older). Drug exposure data will be obtained from pharmacy claims for dispensed medications and OS diagnosis information will be obtained through linkages with state cancer registry files using trusted third parties or de-identification software.
RESULTS: The process for implementing the linkages between the pharmacy claims databases and multiple cancer registries will be described including the average length of time for approval and the linkage process for both claims databases.
CONCLUSIONS/IMPLICATIONS: Linkage studies allow for monitoring important drug safety issues with minimal patient burden. Large pharmacy claims databases include a record of outpatient medication dispensing and are not anticipated to be biased with regard to the study outcome. Cancer registry data are the most accurate and complete population-based source of cancer outcomes, which use specific cancer codes, minimizing the possibility of misclassification of the tumor type.
