Engaging the Osteological Paradox: A Study of Frailty and Survivorship in the 1918 Influenza Pandemic

Published in 1992, “The osteological paradox: problems of inferring prehistoric health from skeletal samples” highlighted the limitations of interpreting population health from archaeological skeletal samples. The authors drew the attention of the bioarchaeological community to several unfounded assumptions in the field of paleopathology. They cautioned that bioarchaeologists needed to expand their methodological and theoretical toolkits and examine how variation in frailty influences mortality outcomes. This dissertation undertakes this task by 1) establishing a new approach for handling missing paleopathology data that facilitates the use of new analytical methods for exploring frailty and resiliency in skeletal data, and 2) investigating the role of prior frailty in shaping selective mortality in an underexplored epidemic context. The first section takes the initial step of assessing current techniques for handling missing data in bioarchaeology and testing protocols for imputation of missing paleopathology variables. A review of major bioarchaeological journals searching for terms describing the treatment of missing data are compiled. The articles are sorted by subject topic and into categories based on the statistical and theoretical rigor of how missing data are handled. A case study test of eight methods for handling missing data is conducted to determine which methods best produce unbiased parameter estimates. The second section explores how pre-existing frailty influenced mortality during the 1918 influenza pandemic. Skeletal lesion data are collected from a sample of 424 individuals from the Hamann-Todd Documented Collection. Using Kaplan-Meier and Cox proportional hazards, this chapter tests whether individuals who were healthy (i.e. non-frail) were equally likely to die during the flu as frail individuals. Results indicate that imputation is underused in bioarchaeology, therefore procedures for imputing ordinal and continuous paleopathology data are established. The findings of the second section reveal that while a greater proportion of non-frail individuals died during the 1918 pandemic compared to pre-flu times, frail individuals were more likely to die at all times. The outcomes of this dissertation help expand the types of statistical analyses that can be performed using paleopathology data. They contribute to the field’s knowledge of selective mortality and differential frailty during a major historical pandemic.