Background: Monitoring patient survival, a practice routinely employed by many cancer registries, is an essential component of the evaluation of progress against cancer. However, changes in prognosis over time are disclosed with considerable delay, with traditional methods of monitoring cumulative survival.
Methods: This article introduces an alternative approach, denoted "period monitoring." which aims at more timely detection of such changes. The conceptual background and the computational realization of the proposed method are outlined, and its application is illustrated by an empirical example from the population-based cancer registry of Saarland, Germany.
Results: The principle of period monitoring is shown to be analogous to the well established use of period life tables in the field of demography. Computational realization of period monitoring can be achieved with simple modifications of standard survival analysis techniques. Compared with traditional methods of monitoring survival, period monitoring can advance detection of changes in cumulative survival considerably.
Conclusion: Despite some limitations with respect to the ease of data interpretation. period monitoring offers a useful supplement to existing methods of monitoring patient survival.