Tobacco-related deaths and disabilities are on

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1 Nursing intervention and smoking cessation: A meta-analysis Virginia Hill Rice, PhD, RN, CS, FAAN, Detroit, Michigan OBJECTIVE: To determine with meta-analysis the effects of nursing-delivered smoking cessation interventions. RESULTS: Fifteen studies comparing nursing intervention with a control or usual care found intervention to significantly increase the odds of smoking cessation. There was heterogeneity among the study results, but pooling by using a random effects model did not alter the estimate of effect. There was no evidence from indirect comparison that interventions classified as intensive had a larger effect than less intensive ones. There was evidence that interventions were more effective for hospital inpatients with cardiovascular disease than for inpatients with other conditions. Interventions in nonhospitalized patients also showed evidence of efficacy. Nurse counseling on smoking cessation during a screening health check was likely to have less effect. The results indicate the potential benefits of smoking cessation advice and counseling given by nurses to their patients, with reasonable evidence that intervention can be effective. (Heart Lung 1999;28:438-54) From Wayne State University College of Nursing. Reprint requests: Virginia Hill Rice, PhD, RN, CS, FAAN, Professor, Wayne State University College of Nursing, 5557 Cass Ave, Office 366 Cohn, Detroit, MI Copyright 1999 by Mosby, Inc /99/$ /1/ Tobacco-related deaths and disabilities are on the increase worldwide in response to the continued use of tobacco, mainly cigarettes. Tobacco use has reached epidemic proportions in many third world countries even as steady use continues in industrialized nations. 1 Two factors, when considered together, may help to reduce the prevalence of cigarette smoking. These are (1) 90% of smokers want to quit smoking and (2) 70% of smokers visit a health care professional each year. 2,3 Nursing, with the largest number of health care providers worldwide, is involved in the majority of these visits and, therefore, has the potential to have a profound effect on the reduction of tobacco use. Yet nursing s role has been less clearly explicated. Systematic reviews 4,5 have confirmed the effectiveness of advice from physicians to stop smoking. The Agency for Health Care Policy Research (AHCPR) Clinical Practice Guideline 6 notes strong support for physicians to advise every patient who smokes to quit (strength of evidence = A). The findings for advice by nonphysicians, however, have been more equivocal and much weaker. AHCPR reviewers reported Insufficient data exist to assess the efficacy of advice to quit smoking when the advice is given by non-physician clinicians (strength of evidence = C). 6 Nurses are included in the nonphysician clinician category, along with pharmacists, respiratory therapists, and others; the effects for their advice were not examined separately. Another review that evaluated the contribution of health professionals to smoking cessation included few nursing studies. 7 Clearly, a more comprehensive review of nursing s role in smoking cessation is warranted. Such a review is essential if the profession is to endorse the American Nurses Association position, patient education and preventive health care interventions to stop tobacco use should be part of nursing practice. 8 The aim of this review is to examine and summarize randomized clinical trials in which nursing staff provided smoking cessation intervention. The review, therefore, focuses on the nurse as the intervention provider, rather than on a particular type of intervention. Smoking cessation targeted for pregnant smokers is not reviewed here because of the particular circumstance and motivation in these women. Interventions for pregnant smokers have recently been reviewed elsewhere NOVEMBER/DECEMBER 1999 HEART & LUNG

2 Rice Nursing intervention and smoking cessation OBJECTIVES The primary objective of this review was to determine the effectiveness of nurse-delivered interventions on smoking behavior in adults. A priori study hypotheses were that nurse-delivered smoking cessation intervention: 1. Is more effective than no intervention 2. Is more effective if the intervention is more intense 3. Differs in effectiveness with health state and setting of the clients 4. Is more effective if it includes follow-up 5. Is more effective if it includes aids that demonstrate the pathophysiologic effect of smoking This review does not address the incremental effects of providing nicotine replacement therapy (NRT) by nurses, as the effectiveness of NRT is addressed in a separate Cochrane Review. 10 Studies, however, in which advice about nicotine replacement was part of the nursing intervention were included. MATERIALS AND METHODS Criteria for considering studies for this review Type of studies. Inclusion criteria used to select randomized clinical trials were that (1) they had to have at least 2 treatment groups and (2) allocation to treatment groups must have been stated to be random. Studies that used historical controls were excluded. Types of participants. Subjects were adult smokers of either sex recruited in any type of health care setting, the only exception being studies that included pregnant women. Trials in which recent quitters were classified as smokers were included, but sensitivity analysis was performed to determine whether they differed from trials that excluded such individuals. Types of nursing intervention. Nursing intervention is defined as the provision of advice and other content and strategies to help patients quit smoking. Included in the review are smoking cessation studies that compared brief advice with more intensive smoking cessation intervention or compared different types of intervention. Studies of smoking cessation intervention as a part of multifactorial lifestyle counseling or rehabilitation were included only if it was possible to discern the specific nature and timing of the intervention, and to extract data on the outcome effects. Advice was defined as verbal instructions from the nurse to stop smoking, whether or not information was provided about the deleterious effects of smoking. Interventions were grouped into low and high intensity for comparison. Low-intensity intervention was defined as trials where advice was provided (with or without a leaflet) during a single consultation lasting 10 minutes or less with 1 followup visit. High-intensity intervention was defined as trials where the initial contact lasted more than 10 minutes; there were additional materials, such as a manual, strategies other than simple leaflets, or any combination of these interventions. In high-intensity intervention, participants had more than 1 followup contact. 6 Studies where patients were randomized to receive advice vs advice plus some form of NRT were excluded because these were primarily comparisons of the efficacy of NRT rather than the efficacy of nursing advice. A series of studies to examine the combination of nursing advice and NRT are yet to be conducted. Types of outcome measures. The principal outcome used in this review was smoking cessation rather than a reduction in smoking behavior or a reduction in withdrawal symptoms. Thus, trials not including data on smoking cessation rates were excluded. In each study, the strictest available criterion for defining abstinence was used. 11 Sustained cessation rather than point prevalence abstinence was used where possible. If biochemical validation was used, only subjects who met the biochemical criteria for cessation were regarded as quitters. If contact was lost with patients during follow-up, they were regarded as continuing smokers. Outcome follow-up of at least 6 months was required for study inclusion. Search strategy for identification of studies We searched the Tobacco Addiction Review Group specialized register for trials. This register includes trials located from systematic search of MEDLINE, Embase, and PsycLit. In addition, hand searching of specialist journals, conference proceedings, and reference lists of previous trials and overviews were conducted. We checked all trials with nurse or health visitor (the British term for nurse) in the title, abstract, or keywords for relevance. In addition, the Cumulative Index to Nursing and Allied Health Literature was searched for nursing and smoking cessation and/or intervention from 1983 to the present. Method of review Data extraction. The author and an assistant from the Cochrane Tobacco Addiction Review Group extracted data from the published reports independently. Disagreements were resolved by HEART & LUNG VOL. 28, NO

3 Nursing intervention and smoking cessation Rice referral to a third party. For each trial, the following data were extracted: (1) author(s) and year; (2) country of origin, study setting, and design; (3) number of subjects and definition of smoker ; (4) description of intervention and designation of its intensity (high or low); and (5) outcomes and biochemical validation. See Table I. In trials where the details of the methods were unclear or where the results were expressed in a form that did not allow for extraction of key data, the original investigators were approached to provide the needed information. In studies where participants were lost to follow-up, they were treated as continuing smokers. Quality assessment. The validity of the studies included in the review was examined in relation to the 4 general sources of bias described in the Cochrane Handbook. 12 These were (1) selection bias systematic differences in the securing of the comparison groups; (2) performance bias systematic differences in care apart from the intervention of interest; (3) attrition bias systematic withdrawals from the trial; and (4) detection bias systematic differences in outcome assessment. Only the control of selection bias at entry has been shown to empirically result in systematic differences in the assessment of effect size. 13 A 3-point scale was used, with a grading of A if the effort to control selection bias had been maximal (eg, randomly generated table of assignment had been established before contact with potential subjects), B if there was uncertainty as to how and when random assignments had been made, and C if group allocation was definitely not adequately described or was concealed. Data analysis. The statistical methods used for pooling were as described by Peto s group. 14 This involved calculating, for each trial in the review, the number of expected events (E) in the experimental group, assuming that the intervention had had no effect. This calculation is based on the number of subjects initially randomized, whether or not they completed the study. The number of expected events was then subtracted from the number that were actually observed (O) in the experimental group. Combining these separate differences, that is O-E (observed minus expected), and their variances allows for the calculation of a statistic (and its variance) that is typical of the differences observed between experimental and control groups in the assembled trials. This was used to test the null hypothesis and also to estimate how large any differential effects were. For the latter purpose, the typical odds ratio (OR) and its 95% confidence interval (CI) were calculated by using a fixed effects model. This meant that subjects in 1 trial were never directly compared with subjects in another. Instead, only subjects within a trial were compared, according to the intervention that they received. Using this approach avoided differences in treatments, duration of treatments, follow-ups, and endpoints that could interfere with estimates of effectiveness. This method does not assume that the size of any reduction in smoking cessation rates across trials must be similar. Results are expressed as an OR (intervention/control) for achieving abstinence from smoking at a given point in time together with the 95% CI for this estimate. Tests for heterogeneity were performed by using a Mantel-Haenszel χ 2 statistic. Description of included studies Nineteen randomized clinical trials conducted between 1987 and 1998 in 7 different countries, with adults who used tobacco (primarily cigarettes) met the inclusion criteria and contributed to the review. Overall, 54% of the subjects were women. Seventeen trials recruited hospitalized or primary care clinic patients and 2 studied communitybased adults. Eighteen studies included adults with diagnosed health problems; only 1 of the studies sought essentially healthy community-based participants. Seven of the studies focused on adults with diagnosed cardiovascular health problems, and 1 study focused on patients with respiratory diseases. Fifteen studies with 7912 people contributed to the main comparison of nursing intervention vs control (Table II). In some detail, 1 study 24 compared 2 interventions with a usual care control. The minimal condition included a counseling session and 1 telephone call after discharge from the hospital. In the intensive condition, participants received 3 additional telephone calls, and those who relapsed were offered further face-to-face meetings, and NRT, if needed. We classified both interventions as intensive but compared the intensive and minimal conditions in a separate analysis of the effect of additional followup. Three of the studies examined smoking cessation intervention as a specified component of multiple risk factor reduction interventions in adults with cardiovascular disease. 15,16,18 In all 3 studies, the smoking cessation component was clearly defined, of high intensity, and independently measurable. Follow-up periods for reinforcement and outcome measurements varied across studies, with a tendency for limited reinforcement and shorter follow-up periods in the older studies. All trials had some contact with subjects in the first 3 months of follow-up for restatement of the intervention and/or point prevalence data collection. Four of the 440 NOVEMBER/DECEMBER 1999 HEART & LUNG

4 HEART & LUNG VOL. 28, NO Table I Characteristics of included studies Study Methods Participants Interventions Outcomes Notes Allen, Carlsson et al, Davies et al, DeBusk et al, (Maryland) Recruitment setting: hospital inpatients Intervention: before hospital discharge and 2 wk after discharge Randomization: computer assignment with balanced allocation Country: Sweden Recruitment setting: hospital CCU Intervention: began at home 4 wk after discharge Randomization: method not stated Country: Canada Recruitment setting: healthy adult community-based volunteers Randomization: method not stated (California) Recruitment setting: patients in 5 hospitals Randomization: by centralized computer allocation 116 female post-cabg patients, 25 smokers among them Smoker defined by use of cigarettes during 6 mo before admission 168 survivors of acute MI; 67 smokers among them defined as present smoker by questionnaire 307 essentially healthy adult smokers of at least 5 cigarettes/d 131/293 intervention and 121/292 control AMI patients were smokers, defined as any use of tobacco in 6 mo before admission 1. Multiple risk factor intervention, self-efficacy program: 3 sessions with nurse using AHA Active Partnership Program and a follow-up call. 2. Usual care (standard discharge teaching and physical therapy instructions) 1. Multiple risk factor intervention in secondary prevention unit, 1.5 hrs of smoking cessation as part of 9 hours group/individual counseling, 4 visits to nurse during 9 mo. 2. Usual care, follow-up by general practitioners 1. Time To Quit program delivered by a mentored student nurse trained in program at baseline, with questionnaires at 6 wk and 9 mo. 2. Visit by mentored student nurse without use of Time to Quit 1. Multiple risk factor intervention case-management system with smoking cessation, nutritional counseling, lipid lowering and exercise therapy. Smoking cessation: 2 min physician advice then Abstinence at 12 mo Validation: none Abstinence at 12 mo Validation: none Abstinence at 9 mo Validation: Cotinine < 100 ng/ml Abstinence at 12 mo (point prevalence) Validation: plasma cotinine < 10 ng/ml, or ng/ml, with expired CO < 10 ppm Data on number of quitters derived from percentages; likely to include some who stopped before intervention Effect of training and manuals on nurse intervention Number of quitters derived from smoking cessation rates assumed to be based on number of baseline smokers. Original data sought but not available. Continued. Rice Nursing intervention and smoking cessation

5 442 NOVEMBER/DECEMBER 1999 HEART & LUNG Table I (Continued) Study Methods Participants Interventions Outcomes Notes Family Heart Study, Hollis et al, Both smokers and nonsmokers randomized Country: United Kingdom Recruitment setting: general practice (family practice) patients aged y and partners, identified by household Randomization: by practice (1 of a pair in each of 14 towns), and within intervention practices by individuals to screening/ intervention or 1 y screening (Portland, Ore) Recruitment setting: Internal medicine/family clinics Randomization: By 2 random digits in health record number Physicians blind to assignment 7460 male and 5012 female medical practice patients who reported smoking on a questionnaire 2691 internal medicine/family clinic adults who reported being a smoker on a questionnaire nurse counseling with repeated telephone followups 8 times. NRT offered only to highly addicted patients who relapsed after discharge (intervention group = 10%, usual care = 2%) 2. Usual care, including physician counseling. Group cessation programs available for $50 (2% enrolled) 1. Screening for cardiovascular risk factors and riskrelated lifestyle intervention during a single 1.5 hr visit 2. Delayed screening (at 1 y) for families in the same practice (internal control) and the paired practice (external control) 1. Brief (30 sec) physician advice and pamphlet from nurse. 2. Brief physician message, plus nurse-promoted selfquit attempts/advice, CO feedback, 10 min video and manual (1 of 3 types) and follow-up call for materials. Smoking prevalence at 12 mo Validation: exhaled CO Abstinence at 12 mo (2-point prevalence) Validation: saliva cotinine at 12 mo Not included in meta-analysis because outcome not directly comparable with cessation studies. Smoking prevalence was lower in the intervention subjects at 1 y than in either internal or external practice controls. However, nonreturnees in the intervention group had a higher smoking prevalence at baseline than returning patients. All 3 nurse-mediated interventions compared with physician advice only. Saliva samples only obtained for approximately half of reported quitters. Compliance and confirmation rates did not differ between groups. Continued. Nursing intervention and smoking cessation Rice

6 HEART & LUNG VOL. 28, NO Table I (Continued) Study Methods Participants Interventions Outcomes Notes Janz et al, Lancaster et al, (Michigan) Recruitment setting: Outpatient Med Clinic Randomization: half-day clinics assigned to treatment status Country: United Kingdom Recruitment setting: general practice, recruitment during a visit or by letter. Smokers who completed a questionnaire about smoking habits. Randomization: computer-generated allocation in sealed envelopes Adult smokers ( 5 cigarettes/d) attending clinics 497 general practice adult smokers (at least 1 cigarette/d) 3. Brief physician advice plus nurse-promoted group program: advice, CO, and video. Asked to join group with schedule, coupon, or followup calls. 4. Brief physician advice and nurse-offered choice between selfdirected and group directed assistance for quitting shown both types of materials. 1. Physician discussed personal susceptibility, selfefficacy and concern, nurse counseled on problems and strategies 2. As in 1, plus self-help manual Step-by-Step Quit Kit and 1 telephone call 3. Usual care control (from physicians not involved in study) 1. Physician advice (faceto-face or in a letter) and a leaflet. 2. As in 1, plus invitation to contact a trained practice nurse for more intensive tailored counseling. Up to 5 followup visits offered. Abstinence at 6 mo (selfreport by telephone) Validation: none Sustained abstinence at 12 mo (not smoking at 3 and 12 mo) Validation: saliva cotinine at 3 and 12 mo Compared 1 and 2 vs 3. Interventions included both physician and nurse components. Data derived from graphs of percentages. Original data sought but not available. Only 30% took advantage of extended counseling. Continued. Rice Nursing intervention and smoking cessation

7 444 NOVEMBER/DECEMBER 1999 HEART & LUNG Table I (Continued) Study Methods Participants Interventions Outcomes Notes Lewis et al, Miller et al, Nebot et al, OXCHECK Study Group, Recruitment setting: hospital inpatients (excluding some patients with cardiac conditions) Randomization: predetermined computer-generated code (California) Recruitment setting: hospital inpatients Randomization: sealed envelopes Country: Spain Recruitment setting: primary care center (unselected) Randomization: primary care teams randomized to intervention Country: United Kingdom Recruitment setting: patients aged y in 5 urban 185 hospitalized adults, self-reported as having regular use of tobacco for at least 1 y 1942 hospitalized patients with heart disease; smokers (any tobacco use in wk before admission) 425 smokers (at least 1 cigarette/d in past wk) 11,090 general practice patients 1. Minimal care: motivational message from physician to quit plus pamphlet 2. Counseling and nicotine patch 3. Counseling plus placebo patch. In addition, groups 2 and 3 received a motivational message and instructions on patch use from physician and 4 sessions of telephone counseling by a nurse, based on cognitive behavioral therapy and motivational interviewing. 3. As in 2, plus nicotine replacement patch (NRT). 1. Intensive: 30 min counseling, video, workbook, relaxation tape and 4 telephone calls 2. Minimal: 30 min counseling and 1 telephone call 3. Usual care 1. Physician advice 2. Physician advice and nicotine gum 3. RN counseling (up to 15 min). All received booklet and offer of follow-up visit or call 1. Health check and risk factor counseling Abstinence at 6 mo (7 d point prevalence) Validation: CO = < 10 ppm Abstinence at 12 mo, also sustained abstinence (3 and 6 mo self-report) Validation: plasma cotinine or family member collaboration at 12 mo Sustained abstinence (2 and 12 mo) Validation: one quarter validated by expired CO at 2 mo Smoking prevalence and reported quitting in previous 12 mo Validation: none Compared 3 vs 1, nurse counseling and placebo patch compared with minimal care to avoid confounding by effect of NRT 1 and 2 vs 3 in main analysis both interventions classified as high-intensity. Cardiovascular and other diagnoses separated in analysis by setting 1 vs 2 in analysis of effect of additional telephone contact (sustained abstinence) Compared 3 with 1 When all intervention patients (including nonattenders) were compared with controls, there was Continued. Nursing intervention and smoking cessation Rice

8 HEART & LUNG VOL. 28, NO Table I (Continued) Study Methods Participants Interventions Outcomes Notes Rice et al, Rigotti et al, Risser et al, Sanders et al, 1989a 30 Sanders et al 1989b general practices (family practice) who returned a baseline questionnaire Randomization: by household, to health checks in 1 of 4 y (Michigan) Recruitment setting: self-referral or by provider Randomization: use of table of random numbers (Boston) Recruitment setting: cardiac surgery unit Randomization: method not specifically described Recruitment setting: nursingstaffed health promotion clinic Randomization: method not specifically described Country: United Kingdom Recruitment setting: primary care clinics (11) Randomization: by day of the week, randomized across weeks and practices. 255 smokers with cardiovascular disease ( 10 cigarettes/d) 87 smokers (at least 1 pack of cigarettes in past 6 mo) scheduled for CABG 90 adult smokers attending health promotion clinic for annual visit who reported smoking 4210 primary care clinic patients identified by questionnaire as smokers 2. Delayed intervention 1. Smokeless program, with delivery by nurse in 5 individual multicomponent sessions 2. Same program, with 5 group sessions by nurse 3. Same program, with written self-help format 4.Usual care control 1. 3-session behavioral model with videotape and face-toface counseling by RN 2. Usual care control min session, self-help materials, skills training, and counseling program 2. As in 1, plus 10 min personalized motivational intervention with spirometry, CO measurement, and discussion of symptoms 1. Asked by physician (following advice to quit) to make appointment with nurse for health check advice, discussion, leaflet, and offer of follow-up by nurse 2. Usual care control Abstinence at 12 mo Validation: saliva thiocyanate Sustained abstinence at 12 mo Validation: saliva cotinine < 20 ng/ml Abstinence at 12 mo (point prevalence) Validation: expired CO Sustained abstinence at 12 mo (self-report of not smoking at 1 mo and 12 mo) and patients who gave date on which they last smoked as before the 1-mo follow-up) Validation: urine cotinine no significant difference in the proportion who had stopped smoking in previous year. Compared 1, 2, and 3 vs 4 Abstinence rates included some smokers who had quit before surgery. Not in main comparison: effect of additional components. No group without intervention (No true control group) Only a sample of usual care group followed up, so not appropriate to use data in main meta-analysis. A significant effect of the intervention was apparent only for the sustained cessation outcome at 1 year, point prevalence abstinence rates were 11.2% for intervention, 10% for control (NS) Continued. Rice Nursing intervention and smoking cessation

9 446 NOVEMBER/DECEMBER 1999 HEART & LUNG Table I (Continued) Study Methods Participants Interventions Outcomes Notes (Part 2 of above) 30 Taylor et al, Tonnesen et al, Vetter et al, Country: United Kingdom Recruitment setting: primary care clinics (11) Randomization: method not specifically described. (California) Recruitment setting: hospital (patients with acute myocardial infarction) Randomization: random numbers in sealed envelopes Country: Denmark Recruitment setting: outpatient chest clinic Randomization: method not specifically described Country: United Kingdom (Wales) Recruitment setting: general medical clinic Randomization: method not specifically described 751 primary care clinic smokers who attended a health check (having been randomly allocated to an intervention offering a health check see Sanders 1989a) 173 hospitalized smokers following acute MI. Smoker defined as patient with any use of tobacco. 507 smokers of < 10 cigarettes/d or of > 10 cigarettes/d who had refused a trial of NRT. Nurses given 8 hr training and 3 problem-solving meetings. 471 smokers aged 60+ who completed a health questionnaire in general practice clinic 1. Health check from a practice nurse; advice, leaflet, and offer of follow-up 2. As in 1 with demonstration of expired CO levels 1. Nurse counseling on selfefficacy, benefits and risks, and manual on coping with high risk situations Further telephone counseling as needed for up to 6 mo 2. Usual care control 1. Motivational approach, 5 min of benefits/risks, brochures on hazards and how to quit, 4-6 wk letter sent 2. Control: questionnaire and CO measurement. No advice to stop smoking. Patients received a letter asking them to visit physician 1. Approximately half to intervention that advised of importance of stopping smoking by physician and then referred to see practice nurse who gave specific advice on lifestyle factors, concentrating on quitting smoking 2. No contact, completed questionnaire only Sustained abstinence at 12 mo (self-report of not smoking at 1 mo and 12 mo and patients who gave date on which they last smoked as before the 1-mo follow-up) Validation: urine cotinine in a sample of participants indicated a relatively high deception rate Abstinence at 12 mo Validation: serum thiocyanate < 110 nmol/l, expired CO < 10 ppm Sustained abstinence at 12 mo (stopped during intervention and no reported smoking during y) Validation: CO < 10 ppm Abstinence at 6 mo (point prevalence) Validation: expired CO (cut-off point not stated) Compared 2 with 1 for effect of CO demonstration as an adjunct to nurse advice. This was part of same study as Sanders 1989a, and randomized a subgroup of participants in the main study Nurses averaged 3.5 hours per patient, including telephone contact. Slightly higher loss to followup in control group. Nicotine gum was prescribed to 5 patients. Nursing intervention and smoking cessation Rice

10 Rice Nursing intervention and smoking cessation studies had less than 1 year final outcome data collection. 17,21,23,33 The rest had follow-up at 1 year or beyond. The outcome criterion used for this metaanalysis was the longest follow-up of 6 months and beyond. There was no evidence from a subgroup analysis that the differences in length of follow-up explained any of the heterogeneity in study results. Methodologic quality of included studies Seven (44%) of the trials received an A grade for using a randomization process established before contact with subjects. The majority employed some form of computer-generated allocation system. Three studies (19%) received a B grade. In 1 of these studies the last 2 digits on the patient record were used for assignment 20 ; in the second, random assignment was by day of the week and type of clinical practice 30 ; and in the third, intervention teams were randomly assigned rather than participants. 25 The remaining 6 studies (37%) did not specify exactly how random assignment was achieved; these studies received a C grade. All studies included adults 18 years and older who used some form of tobacco, and most included men and women, except for Allen, 15 who studied women only. The definition of tobacco use varied, and in some cases the studies included recent quitters. Definition of abstinence ranged from single point prevalence to sustained abstinence (multiple point prevalence with self-report of no slips or relapses). In 1 study we used validated abstinence at 1 year rather than continuous self-reported abstinence because only the former outcome was reported for disease diagnosis subgroups. 24 Validation of smoking behavior by using biochemical analysis of body fluids (cotinine or thiocyanate) was reported in 7 (41%) of the studies. Expired carbon monoxide (CO) was used as a verifier in another 7 (41%) of the trials. Three studies (18%) relied on self-reports of smoking cessation only. Almost all the trials used convenience rather than randomly selected samples. Only 1 of the studies reviewed did not let subjects know initially that they were going to be part of a smoking cessation study. 33 In most trials, the basis for sample size selection was not specified a priori, nor was a power analysis conducted after the fact, and most studies did not present refusal to participate rates. Although a few studies did not report drop out rates, most tried to account for all subjects in their sample and included nonreporters as continuing smokers. Drop out rates, both before and after informed consent, varied considerably across studies. MAIN RESULTS Effects of intervention vs control/usual care Smokers offered advice by a nursing professional had an increased likelihood of quitting, compared with smokers without nursing intervention, but there was significant statistical heterogeneity between the results of the 15 studies contributing to this contrast (χ , df 14, P >.001). Inspection of the results suggested that the heterogeneity was because of 2 outlying trials. One showed a large positive effect of intervention 31 and 1 a significant negative effect. 27 In the prespecified subgroup analyses there was no significant heterogeneity within groups that did not include these trials. Pooling all trials gave an OR of 1.43, with 95% CIs of 1.24 to 1.66 at the longest followup. Because of the heterogeneity, we also examined the results of pooling by using a random effects model. This did not greatly alter the OR, but did widen the CIs (OR 1.45, 95% CI ). Some smokers in the study by Taylor et al 31 had been encouraged to use NRT. Exclusion of these people did not alter the significant effect of the intervention in this study. In the study by Miller et al, 24 more people in the intervention conditions than the control used NRT (44% of intensive and 39% of minimal intervention vs 29% of control). People who were prescribed NRT had lower cessation rates than those who were not, but the relative differences in cessation rates between the usual care and intervention groups were similar for the subgroups who did and did not use NRT. However, because of the different rates of use of NRT, it is probable that the increased use of NRT contributed to the effect of the nursing intervention. Effect of intervention intensity There was no evidence from indirect comparisons that interventions that were classified as higher intensity were more effective in successfully quitting. Although the point estimate for the pooled effect of lower intensity trials was larger, the CIs were wide and overlapped with those for highintensity interventions. The pooled OR for the 10 trials of high-intensity interventions was 1.39 (95% CI ) compared with an OR of 1.67 (95% CI ) for the 5 low-intensity trials. Once again there was heterogeneity among the high-intensity subgroup because of the same 2 trials. HEART & LUNG VOL. 28, NO

11 Nursing intervention and smoking cessation Rice Table II Nursing intervention for smoking cessation vs control trials grouped by intensity of intervention Experiment Control Peto OR Weight Peto OR (n/n) (n/n) (95% CI fixed) % (95% CI fixed) Favors Favors control treatment Study High-intensity intervention Allen, /14 6/ [0.30, 7.16] Carlsson, /32 9/ [1.04, 7.44] DeBusk, /131 64/ [1.25, 3.46] Hollis, / / [1.09, 2.77] Lancaster, /249 10/ [0.31, 2.03] Lewis, /62 3/ [0.29, 6.07] Miller, / / [1.03, 1.58] Rice, /207 16/ [0.08, 0.46] Rigotti, /44 22/ [0.41, 2.20] Taylor, /84 20/ [1.98, 6.83] Subtotal (95% CI) 546/ / [1.19, 1.64] χ (df = 9) Z = 4.06 Low-intensity intervention Davies, /153 4/ [0.10, 2.57] Janz, /144 12/ [0.84, 3.38] Nebot, /81 7/ [0.47, 5.63] Tonnesen, /254 3/ [0.76, 8.31] Vetter, /237 20/ [1.00, 3.12] Subtotal (95% CI) 75/869 46/ [1.14, 2.45] χ (df = 4) Z = 2.65 Total (95% CI) 621/ / [1.24, 1.66] χ (df = 14) Z = 4.77 Effects of differing health states and client settings Trials in hospitals recruited patients with health problems. Studies in family medicine clinics, in general, did not select patients with particular health problems. Therefore, setting and disease diagnosis were combined into a subgroup analysis (Table II). For hospitalized patients with cardiac disease, the OR was 1.68 (CI ). There was heterogeneity among trials in hospitalized smokers with cardiovascular disease because of the strong intervention effect in 1 of the 3 trials. 31 The largest trial of the 3 found an effect that just reached statistical significance. 24 Three trials that included a smoking cessation intervention from a nurse as part of cardiac rehabilitation gave a pooled effect, which more than doubled the odds of smoking cessation (OR 2.14, 448 NOVEMBER/DECEMBER 1999 HEART & LUNG

12 Rice Nursing intervention and smoking cessation Table III Nursing intervention for smoking cessation vs control trials by study settings and populations Control Peto OR Weight Peto OR Experiment (n/n) (95% CI fixed) % (95% CI fixed) Favors Control Favors treatment Study Smoking intervention as part of multifactorial intervention in patients with cardiovascular disease Allen, /14 6/ [0.30, 7.16] Carlsson, /32 9/ [1.04, 7.44] DeBusk, /131 64/ [1.25, 3.46] Subtotal (95% CI) 117/177 79/ [1.39, 3.31] χ (df = 2) Z = 3.45 Smoking intervention alone in hospitalized smokers with a cardiovascular disease Miller, /320 74/ [1.02, 2.05] Rigotti, /44 22/ [0.41, 2.20] Taylor, /84 20/ [1.98, 6.83] Subtotal (95% CI) 169/ / [1.26, 2.24] χ (df = 2) Z = 3.57 Smoking intervention alone in other hospitalized smokers Lewis, /62 3/ [0.29, 6.07] Miller, / / [0.91, 1.56] Subtotal (95% CI) 149/ / [0.92, 1.56] χ (df = 1) Z = 1.32 Smoking intervention alone in nonhospitalized smokers with a cardiovascular disease Rice, /207 16/ [0.08, 0.46] Subtotal (95% CI) 24/207 16/ [0.08, 0.46] χ (df = 0) Z = 3.72 Smoking intervention alone in other nonhospitalized smokers Davies, /153 4/ [0.10, 2.57] Hollis, / / [1.09, 2.77] Janz, /144 12/ [0.84, 3.38] Lancaster, /249 10/ [0.31, 2.03] Nebot, /81 7/ [0.47, 5.63] Tonnesen, /254 3/ [0.76, 8.31] Vetter, /237 20/ [1.00, 3.12] Subtotal (95% CI) 162/ / [1.20, 2.10] χ (df = 6) Z = 3.20 HEART & LUNG VOL. 28, NO

13 Nursing intervention and smoking cessation Rice Table IV Value of added telephone support in nursing intervention and smoking cessation Experiment Control Peto OR Weight Peto OR (n/n) (n/n) (95% CI fixed) % (95% CI fixed) Favors Favors Control treatment Study Miller, /540 64/ [1.00, 1.96] Total (95% CI) 100/540 64/ [1.00, 1.96] χ (df = 0) Z = % CI ). 15,16,18 Among hospitalized smokers without cardiac disease, the OR for cessation was 1.20, but the confidence intervals did not exclude 1 (95% CI ). There was no evidence for an effect of an intervention in 1 trial among nonhospitalized adults with cardiovascular disease (OR 0.19, 95% CI ). 27 Subgroup analysis in that study, however, suggested that smokers who had had cardiovascular bypass surgery were more likely to quit, and these patients were overrepresented in the control group that received advice to quit but no structured intervention. Smoking intervention in 7 trials in other nonhospitalized adults gave an estimated 50% increase in the odds of success (OR 1.58, 95% CI ). A sensitivity analysis testing the effect of excluding the 2 trials in which a combination of nursing intervention and advice from a physician was used still found a significant effect (OR 1.49, 95% CI ). Effects of additional telephone support Repeated telephone support 24 increased the cessation rate. The lower CI, however, was only 1 (OR 1.40, 95% CI ). See Table IV. Effects of physiologic feedback Two trials that evaluated the effect of physiological feedback as an adjunct to nursing intervention showed little effect at maximum followup. 29,30 Neither trial revealed evidence for an effect of feedback, and the pooled OR was 0.79 (95% CI ). OTHER FINDINGS We identified 3 studies in which nurses gave smoking cessation advice as part of health check (screening) cardiovascular programs in general practice (family medicine). 19,26,30 Although they met the main inclusion criteria, in 2 of the trials the design did not allow for data extraction for metaanalysis in a format comparable to that of other studies. 19,26 In the third only a random sample of the control group was followed up. 30 Therefore, these trials are discussed separately. The trial by Sanders et al, 30 in which smokers visiting their family physician were asked to make an appointment for cardiovascular health screening, reported that only 25.9% of the patients made and kept such appointments. The percentage who had quit at 1 month and at 1 year and reported last smoking before the 1-month follow-up was higher in both the attendees (4.7%) and the nonattendees (3.3%) than in the usual care controls (0.9%). This suggested that the invitation to make an appointment for health screening could have been, in and of itself, an antismoking intervention and that the additional effect of the structured nursing intervention was small. For the OXCHECK study that used similar health checks, comparable data do not exist because the households had been randomly assigned to be offered the health check in different years. 26 Investigators compared the proportions of smokers who claimed to have stopped smoking in the previous year in the intervention patients attending for their 1-year follow-up and in the control group attending to receive their first health check. They found no difference in the proportions that had reported smoking cessation in the previous year. The Family Heart Study offered nurse-led cardiovascular screening for men aged 40 to 59 years and their partners, with smoking cessation as one of the recommended lifestyle changes. 19 Cigarette smokers were invited to come for up to 3 further visits. Smoking prevalence was lower among those who returned for the 1-year follow-up than in the control groups screened at 1 year. This difference 450 NOVEMBER/DECEMBER 1999 HEART & LUNG

14 Rice Nursing intervention and smoking cessation Table V Value of physiologic feedback in nursing intervention and smoking cessation Experiment Control Peto OR Weight Peto OR (n/n) (n/n) (95% CI fixed) % (95% CI Fixed) Favors Control Favors treatment Study Demonstration of spirometry and CO measurement Risser, /45 9/ [0.10, 1.07] Subtotal (95% CI) 3/45 9/ [0.10, 1.07] χ (df = 0) Z = 1.85 Demonstration of CO levels Sanders, 1989a 30 18/376 17/ [0.54, 2.09] Subtotal (95% CI) 18/376 17/ [0.54, 2.09] χ (df = 0) Z = 0.16 Total (95% CI) 21/421 26/ [0.44, 1.44] χ (df = 1) Z = 0.76 was reduced if nonreturnees were assumed to have continued to smoke, and CO-validated cessation was used. In that case there was a reduction of only about 1% point, and the evidence that there was a true reduction was weak. DISCUSSION The results of this meta-analysis support a modest but significantly positive effect for smoking cessation intervention by nurses. A structured smoking cessation intervention delivered by a nurse was more effective than usual care on smoking abstinence at 6 months or longer after treatment. The direction of effect was consistent in different intensities of intervention, in different settings, and in smokers with and without tobacco-related illnesses. In the 1 study 27 that showed a statistically significant higher cessation rate in a control group, participants had been advised to quit, and the control group included a larger proportion of people who had had coronary artery bypass graft (CABG) surgery. A multivariate analysis of 1-year follow-up data in this study revealed quitters were significantly more likely to be male, to be younger than 48 years of age, to have had individual vs group or no cessation instructions, and to have had a high degree of perceived threat relative to their state of health. This suggests that multiple factors may need to be considered when weighing the effect of smoking cessation intervention. Overall, the findings of this meta-analysis need to be interpreted carefully in light of the methodologic limitations of both the review and the clinical trials. In terms of the review, it is possible that there was a publication selection bias because only tabulated data derived from published works were used. 34 Data from the unpublished or missed studies could have shown more or less favorable results. Second, the results of a meta-analysis (based on the findings of many small trials) should be viewed with caution even when the combined effect is statistically significant. 35 In this analysis, 1 study contributed almost 50% of the weight to the overall analysis, while the next largest added only 10% of the weight. Finding statistical heterogeneity between the odds of cessation in different studies limits any assumption that interventions in any clinical setting and with any type of patient are equally effective. A difference among the studies that may have contributed to the differences in outcome was baseline cigarette use. Other work has shown a relationship between the number of cigarettes smoked per day and success in quitting smoking; the more addicted the individuals, the more difficult it is for them to quit. 36 Studies that recruited a higher proportion of lighter smokers or that includ- HEART & LUNG VOL. 28, NO

15 Nursing intervention and smoking cessation Rice ed recent quitters could have achieved better results. Interestingly, the studies in the meta-analysis that reported the highest rates of cigarette use had the weakest effect for the intervention 17,27 Although 3 trials included recent quitters in their recruitment, there was no evidence that these trials had different results. The finding of similar effects for high-intensity and low-intensity smoking cessation intervention by nurses was comparable to those for physicians advice 4,5 Presumably, the more components added to the intervention, the more intense the intervention; however, assessing the contribution of factors such as total contact time, number of contacts, and content of the intervention was difficult. Our division of the studies into categories of high-intensity and low-intensity, based on the length of initial contact, number of follow-ups, and smoking abstinence may not have accurately distinguished between the key elements that could have contributed to greater efficacy. We found that the nature of the smoking cessation interventions ranged from advice only to more intense interventions with multiple components and that the description of what constituted advice only varied. In most trials, advice was given to stop smoking because of some existing health problem. To make most interventions more intense, verbal advice was supplemented with a variety of counseling messages, including benefits and barriers to cessation 31 and effective coping strategies. 15 Manuals and printed self-help materials also were added to many interventions, along with repeated follow-ups. 20,24 In 2 studies in the low-intensity category, advice from a physician was also part of the intervention, and this almost certainly contributed to the overall effect. 21,33 The largest study in the high-intensity subgroup 24 produced only relatively modest results. This was due in part to the effect of the minimal treatment condition that consisted of just 1 followup telephone call. If these investigators intensive condition alone had been used in the comparison, the estimate of effect in the intensive intervention subgroup of trials might have been increased. There was some evidence that the effect of intervention was greater for patients with diagnosed cardiovascular disease. This pattern was evident in hospitalized smokers who received cessation information alone or who received cessation instruction as part of a multifactorial intervention. However, 2 of the multifactorial interventions trials 15,16 did not use biochemical validation of cessation, and in the third 18 we were unable to confirm the proportion of dropouts with the study authors. The impact of intervention may, therefore, have been overestimated. One study provided data on the effect of the same interventions in smokers with different types of illness and did show a greater effect for intervention in patients with cardiovascular disease. 24 In these individuals the intervention increased the 12-month cessation rate from 24% to 31%, which just reached statistical significance. In other types of patients, the rates were increased from 18.5% to 21%, an effect that did not reach statistical significance. In this study patients were eligible if they had smoked any tobacco in the month before hospitalization, but were excluded if they had no intention of quitting (although they were also excluded if they wanted to quit on their own). These criteria may have contributed to the relatively high cessation rate achieved. Also, a higher proportion of patients in the intensive treatment group than in the minimal care or usual care intervention groups were prescribed NRT. However, the intervention was also effective in those not prescribed NRT. Those given NRT were heavier smokers (with higher levels of addiction) who achieved lower cessation rates than those who did not use NRT. This suggests that nursing professionals may have an important window of opportunity to intervene with patients in the hospital setting or at least to introduce the idea of not resuming tobacco use after hospital discharge. The size of the effect may be dependent on the reason for hospitalization. The additional telephone support, with the possibility of another counseling session for people who relapsed after discharge, seemed to contribute to more favorable outcomes in the intensive intervention used by Miller et al. 24 Providing additional physiologic feedback in the form of spirometry and demonstrated CO levels as adjuncts to nursing intervention did not appear to have an effect. Three studies used this approach 20,29,30 ; none was conducted with hospitalized patients. The identification of an effect for a nurse-mediated intervention in smokers who were not hospitalized is based on 7 studies, only the largest of which showed a statistically significant effect. This study showed an increase in the cessation rate from 2% in patients who received only advice from a physician to 4% when a nurse delivered 1 of 3 additional interventions that included a video, written materials, and a follow-up telephone call. 20 Baseline cessation rates were relatively low in all studies, and this, combined with 452 NOVEMBER/DECEMBER 1999 HEART & LUNG