Discussing the Strehler-Mildvan model of mortality

BACKGROUNDHalf a century ago, Strehler and Mildvan (1960) published a seminal paper that, based on certain assumptions (postulates), theoretically 'justified' the Gompertz law of mortality. OBJECTIVEWe intend to discuss the assumptions and limitations of the original Strehler-Mildvan model (as well as of the Strehler-Mildvan correlation), and to consider some modifications and departures from this model. METHODSWe use the framework of stochastic point processes for analyzing the original Strehler-Mildvan model.We also suggest using the 'lifesaving approach' to describe the departure from rectangularization due to the shifts in the survival curves for human mortality that were observed in the second half of the previous century. RESULTSWe show that the Strehler-Mildvan model can be justified only under the additional assumption that the process of shocks (demands for energy) follows the Poisson pattern.We also suggest a modification that accounts for the oldest-old mortality plateau.