Fig. 1

Sensitivity Analysis for Unmeasured Confounding Between Periodontal Treatment Before, During and Post-Gestation and IUGR. Sensitivity analysis to evaluate the impact of unmeasured confounding of the association between periodontal treatment before (top panel), during (middle panel), and post-gestation (bottom panel) and IUGR. The observed confounder-adjusted odds ratio and 95% confidence interval are also shown for each panel. The unmeasured confounding bias-corrected odds ratio of IUGR for each of the three periodontal treatment periods are shown for prevalence estimates varying from 0.5 to 6.0% of the unmeasured confounder among both the IUGR and non-IUGR groups. The odds ratio of IUGR in relation to the unmeasured confounder is assumed to be 1.25. The red circle for each panel shows the bias-corrected odds ratio for one scenario of the prevalence of the unmeasured confounder of 2% and 4% among IUGR and non-IUGR groups, respectively, and the odds ratio of IUGR in relation to the unmeasured confounder of 1.25. The bias-corrected odds ratio for each of the three scenarios are 0.9 (95% CI 0.6, 1.5) for pre-gestation periodontal treatment, 1.6 (95% CI 1.1, 2.3) for periodontal treatment during pregnancy, and 2.0 (95% CI 1.6, 2.3) for periodontal treatment post-gestation