APOE and Cognitive impairment: The results, shown in Tables 4–5 and Fig. 3, show that high-impact pain was associated with a 52% (95% CI: 37–69%) increased risk of objective cognitive impairment as compared to having low-impact or no pain only in those who were negative for APOE4, and this relationship was maintained after adjustment for additional explanatory factors (aHR = 1.21, 95% CI: 1.07, 1.36).