Quit smoking; earlier cessation offers greater benefit

Cost: Quitting saves cigarette costs, described by the source as around 20–30 yuan for a pack a day. Withdrawal can take weeks to months and requires persistence. Specific treatment options appear in the following entries.

In plain language: The source reports a lifespan difference of over ten years between current and never smokers and describes quitting before age 40 as avoiding around 90% of the excess mortality risk from continued smoking. Earlier quitting gives greater benefit. It also reports higher odds of fracture nonunion among smokers, while noting the observational evidence's limitations.

Findings reported by the source: A US observational cohort found current smokers' life expectancy more than ten years shorter than never smokers'. Quitting before 40 avoided around 90% of excess mortality from continuing; quitting at 25–34, 35–44 and 45–54 was associated with around ten, nine and six additional years, respectively. Chinese cohort data from the 2010s reported mortality RRs of 1.65 for urban male smokers and 1.22 for rural male smokers. After ten years of voluntary cessation, the source describes the excess risk as approaching disappearance. A synthesis of 19 observational fracture studies reported adjusted nonunion odds of 2.32 (95% CI 1.76–3.06) for smokers, with higher risk also described for tibial and open fractures. In a Swedish randomized trial after acute fracture surgery, at least one postoperative complication occurred in 20% of 50 people assigned to a six-week cessation program and 38% of 55 comparison participants. For planned operations, intensive cessation beginning four to eight weeks beforehand, with weekly counselling and nicotine replacement, was associated with fewer complications (RR 0.42, 95% CI 0.27–0.65; two trials, 210 participants).

Source author's evidence grade: A; not site verification or professional approval.

Notes: The source reports an estimated 603,000 deaths worldwide from second-hand smoke in 2004, around 1% of all deaths that year, and emphasizes avoiding exposure, especially for children. For methods, see the following entries 3–6 on cessation medicines, choosing a quit date, cessation clinics and electronic cigarettes. Fracture nonunion estimates come from observational studies, where residual differences between smokers and nonsmokers cannot be entirely removed. The postoperative fracture trial had only 105 participants; the source notes that an alternative analysis did not give a statistically significant difference.

Original source bibliography (titles retained as supplied): Jha P 等 (2013). 21st-century hazards of smoking and benefits of cessation in the United States. NEJM. https://doi.org/10.1056/NEJMsa1211128；Chen Z 等 (2015). Contrasting male and female trends in tobacco-attributed mortality in China: evidence from successive nationwide prospective cohort studies. Lancet. https://doi.org/10.1016/S0140-6736(15)00340-2；Oberg M 等 (2011). Worldwide burden of disease from exposure to second-hand smoke: a retrospective analysis of data from 192 countries. Lancet. https://doi.org/10.1016/S0140-6736(10)61388-8（二手烟那两个数字）；Scolaro JA 等 (2014). Cigarette smoking increases complications following fracture: a systematic review. J Bone Joint Surg Am. https://doi.org/10.2106/JBJS.M.00081；Nåsell H 等 (2010). Effect of smoking cessation intervention on results of acute fracture surgery: a randomized controlled trial. J Bone Joint Surg Am. https://doi.org/10.2106/JBJS.I.00627；Thomsen T 等 (2014). Interventions for preoperative smoking cessation. Cochrane Database Syst Rev. https://doi.org/10.1002/14651858.CD002294.pub4（骨折和手术那几个数字）