Childhood Famine Exposure and Late‐Life Edentulism: Evidence From Natural Experiments
Sebastian‐Edgar Baumeister, Colman McGrath, Thomas Kocher, Gustavo G. NascimentoABSTRACT
Aim
To examine whether childhood famine exposure affects late‐life edentulism using natural experiments from Asia, Europe and America.
Materials and Methods
We utilised historical famines as exogenous shocks. Data were pooled from 10 population‐based studies across eight countries (165,586 participants). Because the famine‐exposed cohort is older at survey than the comparison cohort, we separated famine exposure from the birth‐cohort age gradient using a regression discontinuity in time, an interrupted time series, a region‐of‐birth famine‐intensity difference‐in‐differences, a pre‐famine comparison cohort and applied negative controls.
Results
The crude positive association (risk ratio [RR] 1.69) was eliminated after adjustment for current age (RR 1.07, 95% confidence interval (CI) 0.92–1.23), and the famine cohort did not differ from the older pre‐famine cohort (RR 0.97). The regression discontinuity (+0.13% points, 95% CI: −1.50 to +1.77), interrupted time series (−4.01% points, p = 0.15) and the region‐of‐birth difference‐in‐differences in the two Chinese cohorts (unadjusted, both p ≥ 0.07) were null, as were all negative controls.
Conclusions
Once the birth‐cohort age gradient is accounted for, childhood famine exposure shows no detectable effect on late‐life edentulism; the crude positive association is largely explained by age confounding, which cross‐sectional famine‐cohort comparisons do not address.