Question:
In patients who smoke and are scheduled for surgery, does a preoperative smoking intervention improve smoking cessation and reduce postoperative complications?
Data sources:
Studies were identified in the specialized register of the Cochrane Tobacco Addiction Group, MEDLINE, EMBASE/Excerpta Medica, and CINAHL up to April 2010.
Study selection and assessment:
Studies were included if they were randomized controlled trials (RCTs) that evaluated any preoperative intervention to help smokers give up smoking by the time of their elective surgery. Studies of intraoperative or postoperative interventions were excluded. Study quality was assessed with use of the Cochrane Collaboration Risk of Bias tool.
Main outcome measures:
The primary outcome measure was the prevalence of smoking cessation at the time of surgery and twelve months after surgery. Secondary outcome measures were any postoperative complications, wound complications, cardiopulmonary complications, admission to the intensive care unit, length of stay, and mortality.
Main results:
Eight RCTs (n = 1156) met the inclusion criteria. Experimental interventions included face-to-face counseling (5 RCTs), computer and telephone counseling (1 RCT), a letter advising patients of the benefits of stopping smoking and contact details of a smoking-cessation service (1 RCT), and a 20-minute face-to-face meeting or a 10-minute telephone reminder (1 RCT). Patients in control groups received standard care with smoking-cessation advice that ranged from information about the risks of smoking in relation to surgery to advice to maintain current smoking habits. Two RCTs were categorized as intensive interventions (>1 meeting or telephone session over several weeks), and six RCTs were categorized as brief interventions (1 meeting or telephone session or letter). Smoking cessation at the time of surgery was increased in seven of eight RCTs, with greater effect among the studies with intensive interventions. Because of substantial heterogeneity, the intensive and brief intervention groups of trials were not pooled (Table). Among four trials evaluating twelve-month cessation rates, the two trials with intensive interventions showed sustained quit rates while the two trials with brief interventions did not maintain quit rates (Table). In five RCTs reporting postoperative complications, two trials offering intensive interventions showed a reduced prevalence of complications and three trials with brief interventions showed no difference between groups. Overall and in the intensive intervention trials, the smoking cessation intervention reduced any postoperative complications (Table). Overall and in the intensive intervention trials, wound complications were decreased in the smoking cessation intervention groups (Table). No difference in cardiopulmonary complications was seen between groups (four RCTs). One RCT reported two days spent in the intensive care unit in the smoking cessation group compared with thirty-two days in the control group. No differences between groups were seen for length of hospital stay (four RCTs). Two deaths in the control group were reported in one RCT.
Conclusion:
In patients who smoke and are scheduled for surgery, a smoking-cessation intervention is effective in increasing quit rates at the time of surgery and sustaining quit rates at twelve months after surgery. More intensive smoking-cessation interventions can reduce postoperative complications.
There is little debate that patients who smoke have more perioperative problems than nonsmokers have. The systematic review by Thomsen and colleagues examined the effectiveness of preoperative smoking-cessation programs, including face-to-face consultation, telephone calls, written materials, and nicotine-replacement therapy. Because blinding the patients was not possible, the outcome assessors were blinded in the studies. Unfortunately, the study results were based on self-report; none were verified with use of chemical testing.
After exclusion for various methodological issues, including drop-out rates of >20%, the authors identified seven studies conducted from 2002 to 2009 that met the inclusion criteria. While none of the studies used similar methods or time frames, the data were pooled in a meta-analysis and risk ratios were calculated. Patients who had eight weeks of preoperative smoking-cessation training were more likely to be not smoking at the twelve-month follow-up than control-group patients were. Fewer wound complications occurred in patients who had ceased smoking a number of weeks before surgery. Surprisingly, there were no differences in pulmonary or cardiac events, time in the intensive care unit, hospital length of stay, or death.
In summary, first and foremost, orthopaedic surgeons can encourage their patients to participate in smoking cessation knowing that these programs can be successful. Secondly, and as important, this paper demonstrates that a critical problem for evidence-based summary studies is the need for similar designs that would allow for more accurate comparisons and produce more meaningful results.