Screening for breast cancer: time, travel, and out-of-pocket expenses.

BACKGROUND: We estimated the personal costs to women found to have a breast problem (either breast cancer or benign breast disease) in terms of time spent, miles traveled, and cash payments made for detection, diagnosis, initial treatment, and follow-up. METHODS: We analyzed data from personal interviews with 465 women from four communities in Florida. These women were randomly selected from those with a recent breast biopsy (within 6-8 months) that indicated either breast cancer (208 women) or benign breast disease (257 women). One community was the site of a multifaceted intervention to promote breast screening, and the other three communities were comparison sites for evaluation of that intervention. All P values are two-sided. RESULTS: In comparison with time spent and travel distance for women with benign breast disease (13 hours away from home and 56 miles traveled), time spent and travel distance were statistically significantly higher (P<.001) for treatment and follow-up of women with breast cancer (89 hours and 369 miles). Personal financial costs for treatment of women with breast cancer were also statistically significantly higher (breast cancer = $604; benign breast disease = $76; P < .001) but were statistically significantly lower for detection and diagnosis (breast cancer = $170; benign breast disease = $310; P < .001). Among women with breast cancer, time spent for treatment was statistically significantly lower (P = .013) when their breast cancer was detected by screening (68.9 hours) than when it was detected because of symptoms (84.2 hours). Personal cash payments for detection, diagnosis, and treatment were statistically significantly lower among women whose breast problems were detected by screening than among women whose breast problems were detected because of symptoms (screening detected = $453; symptom detected = $749; P = .045). CONCLUSION: There are substantial personal costs for women who are found to have a breast problem, whether the costs are associated with problems identified through screening or because of symptoms.

Cost effectiveness of a community based research project to help women quit smoking.

OBJECTIVE: To estimate the cost effectiveness of a four year, multifaceted, community based research project shown previously to help women quit smoking. DESIGN: A quasi-experimental matched control design. SETTING: Two counties in Vermont and two in New Hampshire, USA. SUBJECTS: Women aged 18-64 years. METHODS: Costs were the grant related expenditures converted to 2002 US dollars. Survey results at the end of the intervention were used to estimate the numbers of never smokers, former smokers, light smokers, and heavy smokers in the intervention and comparison counties, and 1986 life tables for populations of US women categorised by smoking status to estimate the gain in life expectancy. MAIN OUTCOME MEASURES: Cost effectiveness ratios, as dollars per life-year saved, for the intervention only and for total grant costs (intervention, evaluation and indirect costs). RESULTS: The cost effectiveness ratio for the intervention, in 2002 US dollars per life-year saved, discounted at 3%, was 1156 dollars (90% confidence interval (CI) 567 dollars to infinity), and for the total grant, 4022 dollars (90% CI 1973 dollars to infinity). When discounted at 5%, these ratios were 1922 dollars (90% CI 1024 dollars to 15,647 dollars), and 6683 dollars (90% CI 3555 dollars to 54,422 dollars), respectively. CONCLUSION: The cost effectiveness ratios of this research project are economically attractive, and are comparable with other smoking cessation interventions for women. These observations should encourage further research and dissemination of community based interventions to reduce smoking.

Smoking cessation counseling during periodic health examinations.

Periodic health examinations are an excellent opportunity to counsel smokers to quit. The impact of a specialized smoking cessation counselor on the smoking behavior of patients having periodic health examinations was studied in a general internal medicine practice. One hundred fifty-five smokers having periodic health examinations were randomly assigned to a control group who received usual physician advice or an intervention group who received usual physician advice and two counseling sessions with a smoking cessation counselor. The two groups were similar in all demographic variables, smoking-related baseline variables, and baseline levels of motivation and intention to quit smoking. The smoking status of 97% of the subjects was assessed 6 months later. In the intervention group, 46% made quit attempts and 19% quit, compared with 34% and 12%, respectively, in the control group. Intervention-group smokers made more quit attempts (mean +/- SD, 5.0 +/- 2.5 vs 1.8 +/- 0.2) and had a greater reduction in daily cigarette use (8.4 +/- 1.5 vs 3.5 +/- 1.3). Of the 74% of smokers with higher levels of motivation to quit smoking, more intervention-group smokers attempted to quit (70.8% vs 45.5%) and succeeded in quitting at the 6-month follow-up (27.1% vs 10.9%). Periodic health examinations are an excellent opportunity to counsel smokers to quit, especially those smokers with higher levels of motivation to quit smoking.

Comparison of the levels of the urinary benzene metabolite trans,trans-muconic acid in smokers and nonsmokers, and the effects of pregnancy.

Urinary trans,trans-muconic acid, a ring-opened metabolite of benzene, was quantified in pregnant and nonpregnant smokers. The results of this study were compared with those reported previously in male smokers. The data clearly demonstrate that smoking increases the levels of trans,trans-muconic acid in urine. The mean levels of trans,trans-muconic acid in the urine of groups of male, female, and pregnant smokers were 3.6-, 4.8-, and 4.5-fold higher than those in the nonsmoking counterparts. Mean concentrations of trans,trans-muconic acid in groups of 42 men and 53 nonpregnant women were 0.22 +/- 0.03 (SE) and 0.24 +/- 0.02 mg/g creatinine, or 0.13 +/- 0.6 and 0.13 +/- 0.07 mg/mg cotinine, respectively. These data reveal that urinary trans,trans-muconic acid levels in female smokers are nearly the same as in male smokers. Mean levels of trans,trans-muconic acid in the urine of groups of 63 pregnant and 53 nonpregnant women were 0.27 +/- 0.04 and 0.24 +/- 0.02 mg/g creatinine, or 0.24 +/- 0.06 and 0.13 +/- 0.07 mg/mg cotinine, respectively. Mean concentrations of urinary cotinine in pregnant women were significantly lower than in the group of nonpregnant women (1.13 +/- 0.12 versus 1.82 +/- 0.14 mg/g creatinine). When levels of trans,trans-muconic acid were normalized against urinary cotinine, the mean concentration in urine of pregnant smokers was almost 2-fold greater than that in nonpregnant smokers. This could be due to an increased metabolism of benzene to urinary trans,trans-muconic acid during pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Advising parents to stop smoking: pediatricians' and parents' attitudes.

Pediatricians are in a unique position to address the issues of smoking cessation with parents. Vermont pediatricians and parents of their patients were surveyed to assess attitudes about giving and receiving smoking cessation advice. A questionnaire was mailed to all pediatricians in Vermont, and 72 valid responses were received, for a response rate of 91%. Forty percent of pediatricians routinely took a smoking history from parents and 11% recorded this information in the child's chart. Most pediatricians (94%) reported advising at least 60% of smoking parents to quit, and they spent an average of 4.4 minutes doing this. Barriers to giving advice were lack of time (42%), feeling that parents did not expect advice (25%), and feeling ill at ease giving the advice (25%). Only 8.5% of pediatricians had received training in how to give smoking cessation advice, but 87% were willing to learn methods to give advice briefly. Six hundred seventy-six parents from randomly selected pediatric practices were interviewed. The average parental age was 32, and 84% were women; 49% had never smoked, 30% were former smokers, and 21% were current smokers. Current smokers were less likely to agree with statements about the adverse effects of passive smoke on children. Most parents (56%) felt that pediatricians should give quit-smoking advice to parents, and 52% of smoking parents reported that they would welcome advice. Only 30% of current smokers said advice would bother them somewhat, and 15% had more negative reactions. Parents and pediatricians agreed on the best opportunities to give quit-smoking advice.(ABSTRACT TRUNCATED AT 250 WORDS)

Patterns of regional ventilation in patients with cardiomegaly or left heart failure.

Patterns of regional ventilation have been examined in 42 patients, the majority of whom had clinical evidence of left-ventricular or left-atrial dysfunction. Regional ventilation was studied with xenon-133 and regional perfusion with Tc-99m human albumin microspheres. The presence of a cardiac defect, seen in 54.8% of the washin images, was related to the depth of lung between the posterior heart border and the posterior lung border, but not to cardiac size. Washout patterns were fairly uniform in those patients (43%) who cleared their lungs within 3 min, but were remarkably variable in those with longer washout times. The presence of râles or clinical signs of a pleural effusion, and radiographic evidence of vascular redistribution or pleural effusion, were significantly associated with prolonged washout times. These observations suggest that the prolonged washout is due to edema in the walls of the smaller bronchioles, leading to airflow obstruction.

Smoking in pregnancy, exhaled carbon monoxide, and birth weight.

OBJECTIVE: To examine the relation of cigarette consumption and exhaled carbon monoxide levels during pregnancy and to assess the effect of these smoking measures on birth weight. METHODS: Cigarette consumption and exhaled carbon monoxide levels were recorded at the first prenatal visit and the 36-week visit from women who smoked early in pregnancy. Analysis of variance was used to compare birth weights for differing levels of cigarette consumption and exhaled carbon monoxide. Correlation and regression analyses were used to estimate the effects of the smoking measures at both prenatal visits on birth weight. RESULTS: Cigarette consumption and exhaled carbon monoxide levels at both visits were associated significantly with birth weight. After the first prenatal visit, a reduction in cigarette consumption of at least nine cigarettes per day or in exhaled carbon monoxide of 8 parts per million (ppm) was associated with gains in birth weight of 100 g or more. The proportion of low birth weight (LBW) infants increased significantly with increasing levels of cigarette consumption and with increasing concentrations of exhaled carbon monoxide. CONCLUSION: Substantial reductions in cigarette consumption or in exhaled carbon monoxide levels after the first prenatal visit are needed to achieve gains in birth weight. Not smoking, or having an exhaled carbon monoxide level less than 5 ppm minimizes the likelihood of having an LBW infant.

Smoking relapse prevention during pregnancy. A trial of coordinated advice from physicians and individual counseling.

INTRODUCTION: Our objective was to examine the efficacy of physicians' advice and referral to individual counseling in preventing relapse to smoking among women who were smokers early in pregnancy, but quit prior to their first prenatal visit. DESIGN: A randomized controlled trial of prompted physician's advice and individual relapse prevention counseling during pregnancy compared to usual physician advice. Smoking status was assessed by self-report, exhaled carbon monoxide, and urinary cotinine during pregnancy and by self-report 1 year postpartum. RESULTS: There were no significant differences in relapse rates between the intervention and usual-care groups during pregnancy, nor at 1 year postpartum. Relapse rates were 23% in both groups at the 36-week visit, and 32% and 22%, respectively, 1 year postpartum. Younger age, higher motivation to resume smoking, and higher levels of exhaled carbon monoxide at the first prenatal visit were predictive of relapse to smoking during pregnancy. With the conservative assumption that all those lost to follow-up relapsed, the combined 1-year postpartum relapse rate, 51%, was 17 percentage points lower than we observed in an earlier relapse prevention trial, and 15 percentage points lower than that observed nationally a decade earlier. CONCLUSION: Prompting physicians to provide supportive advice combined with referral to individual relapse prevention counseling did not reduce smoking relapse rates during pregnancy, or postpartum. However, the level of attention paid to smoking by physicians in both intervention and usual-care groups during pregnancy may have contributed to the relatively low relapse rates seen 1-year postpartum.

Helping women quit smoking: baseline observations for a community health education project.

INTRODUCTION: Our objectives were (1) to examine the relationship between women's intention of stopping smoking in the next month and a broad range of mediating variables and (2) to assess the implications of these relationships for intervention components of a comprehensive community-wide health education program to help women quit smoking. METHODS: In preparation for the community-wide program to help women quit smoking, baseline data were collected through a random digit dialing telephone survey of 6,324 adult women, 18-64 years of age. RESULTS: At baseline, smoking prevalence, defined as smoking an average of one or more cigarettes per day, was 25.8% and showed clear relationships with age and income, but most strikingly with education, indicating the need for programs for women of childbearing age with low incomes and fewer years of schooling. Among female smokers, knowledge of the health effects of smoking; motivations toward quitting; confidence in controlling weight, or handling stress, anger or boredom; number of strategies named to cope when upset of angry; number of community smoking cessation resources named; perceptions of support for quitting; and perceptions of norms concerning women smoking varied significantly with level of intention to quit smoking in the next month. CONCLUSIONS: These relationships provided support for the broad range of health behavior change strategies proposed for this community-based program to help women quit smoking.

Smoking relapse prevention counseling during prenatal and early postnatal care.

Our objective was to examine the efficacy of the added effect of individualized smoking relapse prevention counseling on obstetricians' and nurse midwives' usual advice during prenatal care. One hundred and seventy-five pregnant women who were smoking early in their pregnancy, but had quit by first prenatal visit, were randomly assigned to receive the usual advice from their obstetrician or nurse midwife, or usual advice plus individual relapse prevention counseling. Smoking status was measured by self-report, by urinary cotinine/creatinine ratio at the 36-week visit, and by self-report at long-term postpartum follow-up. We found that a smaller percentage of women in the intervention group (8.8%) reported smoking at the thirty-sixth-week visit than those in the usual care group (16.9%), a nonsignificant difference. No significant difference in relapse rates during pregnancy was observed based on urinary cotinine/creatinine ratios, but these rates, 29.5% and 27.9% respectively, were substantially higher than those based on self-report. The average number of days abstinent reported by women in the intervention group was significantly longer than that in the usual care group, 199 days versus 166 days respectively (P < .01). Logistic regression analysis indicated that longest time abstaining before first visit, level of belief in smoking's harm to the fetus, and motivation to smoke were independently related to the probability of relapsing to smoking by the 36-week visit. Long-term relapse rates were not significantly different: intervention group, 50.9%, usual care group, 50.0%.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors associated with arm swelling after breast cancer surgery.

PURPOSE: As life expectancy improves for women with breast cancer, more women will be living with symptoms of lymphedema. This study reports the incidence of arm or hand swelling and associated risk factors in women with invasive breast cancer following surgery. METHODS: Data were obtained from baseline and follow-up interviews of women with invasive breast cancer (n = 145), and mammography and pathology records. The Kaplan-Meier method was used to estimate the probability of developing arm or hand swelling over time. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for arm or hand swelling. RESULTS: Of women in this study, 38% self-reported arm or hand swelling. There was a significantly increased risk of arm swelling if women were under 50 years of age, had axillary node dissection, received chemotherapy, worked outside the home, and had a high household income. There was no association of body weight with swelling. A significantly decreased risk of arm swelling was found in women who were on treatment for high blood pressure. After adjustment for nodal dissection, only age had a significant independent effect. CONCLUSIONS: Our study highlights two important areas of future research that could reduce the incidence of lymphedema. There is a need to better understand the role that treatment for high blood pressure may play in protecting women from arm edema. Second, the potential effect of weight as a modifiable lymphedema risk factor needs to be studied in more detail in light of the conflicting results of different studies.

Life expectancy estimation with breast cancer: bias of the declining exponential function and an alternative to its use.

BACKGROUND: Life expectancy gain (LEG) is an outcome measure commonly estimated with a declining exponential function in a Markov model. The accuracy of such estimates has not been objectively evaluated. PURPOSE: To compare LEGs from declining exponential function estimates with those calculated from population data, using published screening mammography studies as examples. METHOD: SEER-based population data are used to compare LEG calculation with declining exponential function estimation and empiric population data in a new model, the "nested" Markov. RESULTS: Analyses of the LEG of mammographic screening based on the declining exponential function significantly overestimate LEGs for younger women and underestimate them for older women. Because of offsetting errors, all-age analyses paradoxically appear accurate. CONCLUSION: Declining exponential function estimates of LEGs for chronic diseases with low mortality rates and long time horizons are liable to significant bias, especially with limited age cohorts.

The measurement of regional ventilation during tidal breathing: a comparison of two methods in healthy subjects, and patients with chronic obstructive lung disease.

Regional ventilation has been measured in 17 healthy volunteers, and 24 patients with chronic obstructive lung disease during tidal breathing using 133-Xe. The wash-in and wash-out of 133-Xe were recorded by a gamma camera interfaced to a small digital computer. Regional ventilation was calculated as the distribution of tidal volume per unit lung volume-a measure of relative ventilation--and from the wash-out curves as the fractional exchange of air per second. Determination of the regional fractional exchange of air showed a significant difference between the patients with chronic obstructive lung disease and normal subjects for all regions. The distribution of tidal volume per unit lung volume did not effect such a clear separation. Significant correlations were found between the whole-lung fractional exchange of air in the patients with chronic obstructive lung disease and their FEV1 r equal 0-70, MMFR r equal 0-70, FVC r equal 0-56 and FEV1/FVC r equal 0-57. It is suggested that measurement of regional ventilation as the fractional exchange of air is more realistic than methods that determine relative ventilation or only make use of the early part of the wash-out 133-Xe.

Community interventions for reducing smoking among adults.

BACKGROUND: Since smoking behaviour is determined by social context, the best way to reduce the prevalence of smoking may be to use community-wide programmes which use multiple channels to provide reinforcement, support and norms for not smoking. OBJECTIVES: To assess the effectiveness of community interventions for reducing the prevalence of smoking. SEARCH STRATEGY: We searched the Cochrane Tobacco Addiction Group specialised register, MEDLINE (1966-August 2001) and EMBASE (1980-August 2001) and reference lists of articles. SELECTION CRITERIA: Controlled trials of community interventions for reducing smoking prevalence in adult smokers. The primary outcome was smoking behaviour. DATA COLLECTION AND ANALYSIS: Data were extracted by one person and checked by a second. MAIN RESULTS: Thirty two studies were included, of which seventeen included only one intervention and one comparison community. Only four studies used random assignment of communities to either the intervention or comparison group. The population size of the communities ranged from a few thousand to over 100,000 people. Change in smoking prevalence was measured using cross-sectional follow-up data in 27 studies. The estimated net decline ranged from -1.0% to 3.0% for men and women combined (10 studies). For women, the decline ranged from -0.2% to + 3.5% per year (n=11), and for men the decline ranged from -0.4% to +1.6% per year (n=12). Cigarette consumption and quit rates were only reported in a small number of studies. The two most rigorous studies showed limited evidence of an effect on prevalence. In the US COMMIT study there was no differential decline in prevalence between intervention and control communities, and there was no significant difference in the quit rates of heavier smokers who were the target intervention group. In the Australian CART study there was a significantly greater quit rate for men but not women. REVIEWER'S CONCLUSIONS: The failure of the largest and best conducted studies to detect an effect on prevalence of smoking is disappointing. A community approach will remain an important part of health promotion activities, but designers of future programmes will need to take account of this limited effect in determining the scale of projects and the resources devoted to them.

Cigarette smoking control strategies of firms with small work forces in two Northeastern States.

PURPOSE: Cigarette smoking control strategies of firms with small work forces were assessed and compared with those of larger firms. DESIGN: A cross-sectional telephone survey was conducted in 1990 among private employers systematically selected from a proprietary database. SETTING: These firms were located in four counties of two northeastern states. SUBJECTS: Interviews were conducted with managers of 470 small (< or = 25 employees; n = 262), medium (26-50; n = 87), and larger (> 50; n = 121) firms. MEASURES: Interviews assessed characteristics of the firms and their cigarette smoking policies and cessation programs. RESULTS: Small firms differed from larger firms in several areas. They were less likely to have written policies, used fewer methods to communicate their policies, and their policies were consistently less restrictive. Small firms also offered less assistance to employees who wished to quit. CONCLUSIONS: The less restrictive smoking policies reported here may be relatively ineffective in protecting nonsmokers in small firms. Small firms may encounter difficulties introducing more restrictive smoking policies because of the relative closeness of employee relations, smaller work spaces, and inability to deliver smoking cessation services to employees. Methods should be developed to assist managers of smaller firms to implement stronger smoking policies and to devise ways of making cessation assistance more easily available to their employees.

Exhaled carbon monoxide and urinary cotinine as measures of smoking in pregnancy.

We examined the relationships among self-reported cigarette consumption, exhaled carbon monoxide, and urinary cotinine/creatinine ratio in pregnant women. Information on these measures of smoking was collected at first and 36th week prenatal visits. Correlations between cigarette consumption and exhaled carbon monoxide were .65 at the first visit and .70 at the 36th-week visit. For urinary cotinine/creatinine ratio, the correlations were .61 and .65, respectively, at these visits. Correlations with change in cigarette consumption between the two visits were .37 for change in carbon monoxide and .33 for change in urinary cotinine/creatinine ratio. Urinary cotinine/creatinine ratio had slightly higher overall agreement with self-reported smoking status and was less likely to misclassify smokers than carbon monoxide. We conclude that urinary cotinine/creatinine ratio is the more accurate measure for validating smoking status among pregnant women, but exhaled carbon monoxide is the better measure of cigarette consumption and of changes in consumption.

Recruitment in a primary care trial on smoking cessation.

The purpose of this study was to describe and compare the rates of recruitment during a randomized clinical trial on smoking cessation in two primary care practices. One site was a five-physician private family practice setting with about 15,000 patients. During 34 days, 576 patients were screened, of whom 22% were smokers. Among the smokers screened, 54% consented, 33% refused consent, and 13% were called in too early to consent. The other site was a six-physician academic medical practice with about 16,000 patients. During 53 days, 1,692 subjects were screened, of whom 16.2% were smokers. Among the smokers, 19% consented, 81% refused consent, and none were called in early. The enrollment of smokers was 3.3 times greater in the private practice than the academic practice. At the first site, study personnel screened 26.6 subjects per day, whereas the practice receptionist screened only 13.4 subjects per day (P less than .01). A randomized trial of having subjects read the informed consent versus having study personnel read it to them showed no differences in recruitment. The data suggest that private practices may have greater potential for subject recruitment than academic sites, that using study personnel improves recruitment, and that having study personnel actively involved in informed consent does not improve recruitment.

Estimated gains in birth weight associated with reductions in smoking during pregnancy.

OBJECTIVE: To compare the estimated effect on birth weight of reductions in maternal cigarette consumption and urinary cotinine during pregnancy. STUDY DESIGN: An observational study of 641 women with complete data on cigarette consumption, urinary cotinine and infant birth weight. Correlation and regression analyses were used to examine relationships between birth weight, cigarette consumption and urinary cotinine at first and last prenatal visits. RESULTS: Correlations of cigarette consumption and urinary cotinine with infant birth weight were -.23 and -.30 (first visit) and -.26 and -.31 (last visit); all P values were < .001. The regression equation relating urinary cotinine concentrations at first and last visits to infant birth weight explained a significantly larger proportion of the variability in birth weight than the equation relating cigarette consumption at these visits to infant birth weight, 11% vs. 7%, P = .04. Among continuing smokers, both equations predicted gains in birth weight in association with reductions in cigarette consumption, but quitting smoking before the first visit was associated with the most weight gain. As compared to the average infant birth weight of a woman who smoked 20 cigarettes per day throughout pregnancy, the estimated gain in birth weight would be 105 g if she cut down by 10 cigarettes per day after the first visit, 210 g if she quit after this visit and 310 g if she quit before the first visit. CONCLUSION: For women still smoking at their first prenatal visit, infant birth weight is already compromised, but subsequent reductions in cigarette consumption are associated with gains in birth weight. For women who cannot quit smoking, these reductions need to be substantial if increases in birth weight of > 100 g are to be achieved.

Smoking cessation practices in dental offices.

We have surveyed the health promotion efforts of dentists and dental hygienists in general dental practice in Chittenden County, Vermont, in relation to smoking. The response rate was 61 percent. Smoking issues were addressed by 76 percent of dentists and 81 percent of dental hygienists in approximately one quarter of their smoking patients. Although the majority of both dentists and dental hygienists advised their patients to change their smoking behavior, their advice was usually to cut down rather than to quit. Most of the respondents--78 percent of dentists and 93 percent of dental hygienists--considered it appropriate to give advice about smoking during visits for routine dental care and 68 percent and 89 percent, respectively, were willing to learn brief methods of advising their patients about smoking. Experience with giving advice about smoking and agreement that it was appropriate to give such advice were both strongly related to willingness to learn brief methods of giving such advice. In individual dental practices, there were virtually no correlations between the dentist's and the dental hygienist's behaviors as far as the proportion of patients from whom a smoking history was taken, the proportion of smokers advised about smoking, the content of the advice, or the nature of the advice. Only nine percent of dentists and 11 percent of dental hygienists were current smokers.

A statewide survey of dentists' smoking cessation advice.

The general practitioners of the Vermont State Dental Society (251) were surveyed in 1986 to determine their smoking cessation activities. Seventy-eight percent of the dentists completed the survey and 87% reported that they discussed concerns about smoking with their patients who smoke. They estimated spending an average of 2.4 minutes addressing cigarette smoking issues. Among those dentists who discussed smoking issues, the majority (60%) provided some advice on ways to change smoking behavior. The remaining 40% provided no guidance regarding smoking behavior change. The larger the proportion of smokers advised about smoking, the greater the dentists' interest in using incentives to help smokers make an attempt to quit.