Skip to main content
. Author manuscript; available in PMC: 2016 Jul 15.
Published in final edited form as: Nat Rev Cardiol. 2015 Jun 16;12(9):508–530. doi: 10.1038/nrcardio.2015.82

Figure 6.

Figure 6

Proportion (percentage) of excess relative risk (relative risk minus one) of cardiovascular diseases remaining over time since smoking cessation, compared to cancers and chronic obstructive pulmonary disease (COPD). The shaded area shows the uncertainty of the fitted curve. Source: Kontis et al.3

In summary, data on changes in disease-specific mortality RRs after cessation were from a re-analysis of American Cancer Society Cancer Prevention Study II (CPS-II) data.64 A convex constrained b-spline (fitted using the library “cobs” in statistical software R) was fitted to the raw RR data (which can be seen in Figure 2 of Oza and colleagues64) to obtain a smooth continuous relationship of RR over time since smoking cessation. The proportion (percentage) of excess relative risk over time since cessation as RRt−1RR0−1, where RRt is the RR t years after quitting smoking and RR0 is the RR of smokers.