TY - JOUR T1 - PHysical activity, vascular health, and cognitive impairment—reply AU - Vercambre M, Grodstein F, Kang J Y1 - 2012/01/09 N1 - 10.1001/archinternmed.2011.617 JO - Archives of Internal Medicine SP - 83 EP - 84 VL - 172 IS - 1 N2 - We fully acknowledge the observational nature of our study, which only permits the evaluation of associations and is not causal evidence. We were careful throughout the text to state that we observed strong associations between physical activity and cognitive health and that our findings need confirmation in future studies. However, as Smith and colleagues1(p248) state in the largest meta-analysis of clinical trials of physical activity and cognition to date, randomized controlled trials “are limited by logistical constraints in their ability to sustain interventions over prolonged periods of time.” Thus, our observational study, which has evaluated the association between average physical activity over a year and long-term cognitive decline occurring 3.5 years later among 2809 women, provides important data to address the gap in the clinical trial literature. SN - 0003-9926 M3 - doi: 10.1001/archinternmed.2011.617 UR - http://dx.doi.org/10.1001/archinternmed.2011.617 ER -