Predictors of Adherence to Nicotine Replacement Therapy (Nicotine Patch) Among Homeless Persons Enrolled in a Randomized Controlled Trial Targeting Smoking Cessation.

INTRODUCTION: Adherence to smoking cessation treatment is generally low, especially among socio-economically disadvantaged groups including individuals experiencing homelessness and those with mental illnesses. Despite the high smoking rates in homeless populations (~70%) no study to date has systematically examined predictors of adherence to nicotine replacement therapy (NRT) in this population. OBJECTIVE: The aim of this secondary analysis was to identify predictors of adherence to NRT in a smoking cessation trial conducted among homeless smokers. METHODS: Secondary analysis of data from a randomized controlled trial enrolling 430 persons who were homeless and current cigarette smokers. Participants were assigned to one of the two study conditions to enhance smoking cessation: Motivational Interviewing (MI; 6 sessions of MI + 8 weeks of NRT) or Standard Care (Brief advice to quit+ 8 weeks of NRT). The primary outcome for the current analysis was adherence to NRT at end of treatment (8 weeks following randomization). Adherence was defined as a total score of zero on a modified Morisky adherence scale). Demographic and baseline psychosocial, tobacco-related, and substance abuse measures were compared between those who did and did not adhere to NRT. RESULTS: After adjusting for confounders, smokers who were depressed at baseline (OR=0.58, 95% CI, 0.38-0.87, p=0.01), had lower confidence to quit (OR=1.10, 95% CI, 1.01-1.19, p=0.04), were less motivated to adhere (OR=1.04, 95% CI, 1.00-1.07, p=0.04), and were less likely to be adherent to NRT. Further, age of initial smoking was positively associated with adherence status (OR= 0.83, 95% CI, 0.69-0.99, p=0.04). CONCLUSION: These results suggest that smoking cessation programs conducted in this population may target increased adherence to NRT by addressing both depression and motivation to quit. TRIAL REGISTRATION: clinicaltrials.gov: NCT00786149.

CYP2B6 and bupropion's smoking-cessation pharmacology: the role of hydroxybupropion.

Bupropion is indicated to promote smoking cessation. Animal studies suggest that the pharmacologic activity of bupropion can be mediated by its major metabolite, hydroxybupropion. We measured plasma bupropion and its metabolite levels in a double-blind, placebo controlled, randomized smoking-cessation trial. Among the treatment-adherent individuals, higher hydroxybupropion concentrations (per µg/ml) resulted in better smoking-cessation outcomes (week 3, 7, and 26 odds ratio (OR) = 2.82, 2.96, and 2.37, respectively, P = 0.005-0.040); this was not observed with bupropion levels (OR = 1.00-1.03, P = 0.59-0.90). Genetic variation in CYP2B6, the enzyme that metabolizes bupropion to hydroxybupropion, was identified as a significant source of variability in hydroxybupropion formation. Our data indicate that hydroxybupropion contributes to the pharmacologic effects of bupropion for smoking cessation, and that variability in response to bupropion treatment is related to variability in CYP2B6-mediated hydroxybupropion formation. These findings suggest that dosing of bupropion to achieve a hydroxybupropion level of 0.7 µg/ml or increasing bupropion dose for CYP2B6 slow metabolizers could improve bupropion's cessation outcomes.

Association of nicotine metabolite ratio and CYP2A6 genotype with smoking cessation treatment in African-American light smokers.

Cytochrome P450 2A6 (CYP2A6) is the main nicotine (NIC)-metabolizing enzyme in humans. We investigated the relationships between CYP2A6 genotype, baseline plasma trans- 3'-hydroxycotinine/cotinine (3HC/COT) (a phenotypic marker of CYP2A6 activity), and smoking behavior in African-American light smokers. Cigarette consumption, age of initiation, and dependence scores did not differ among 3HC/COT quartiles or CYP2A6 genotype groups. Slow metabolizers (SMs; both genetic and phenotypic) had significantly higher plasma NIC levels, suggesting that cigarette consumption was not reduced to adjust for slower rates of NIC metabolism. Individuals in the slowest 3HC/COT quartile had higher quitting rates with both placebo and NIC gum treatments (odds ratio 1.85, 95% confidence interval (CI) 1.08-3.16, P = 0.03). Similarly, the slowest CYP2A6 genotype group had higher quitting rates, although this trend did not reach significance (odds ratio 1.61, 95% CI 0.95-2.72, P = 0.08). The determination of the 3HC/COT ratio, and possibly CYP2A6 genotype, may be useful in the future for personalizing the choice of smoking cessation treatment in African-American light smokers.

Describing and predicting frequent users of an emergency department.

The objective of this study was to examine the pattern of emergency department (ED) utilization among a cohort of ED users over a 3-year period and to identify factors predicting use. Billing records were used to track one hospital's cohort of adult frequent ED users (> or = 3 visits/per year) over a 3-year period. Frequent and (< 3 visits/per year) infrequent users were compared by age, gender, marital status, insurance status, and hospitalization rates. We compared the number of ED visits by patients in the two groups during follow-up years. Logistic regression analyses were performed to identify factors predicting ED visits by patients in the two groups in the follow-up years. Results from the study showed that frequent users were younger (P < 0.01) and more likely to be male (P < .01). Patients identified as frequent users in the first year were 52 to 77% more likely to visit frequently in the following two years. Logistic regression analysis showed the pattern of prior ED use was the best predictor of future use. Other factors (including age, gender, marital status, insurance status, and hospitalization following an ED visit) were not significant independent predictors of frequent ED use. Our data revealed that the past history of frequent ED use is predictive of future frequent ED use. Studies are needed on effective interventions to determine the reasons for continued frequent ED use.

Pharmacotherapy of smoking cessation.

Tobacco use is the number one cause of preventable diseases in the United States. Smoking accounts for more than 400,000 deaths yearly and 30% of all cancer deaths. Primary care physicians have access to 70% of smokers, approximately 60% of whom are perceived to be in excellent health. Recent advances in the pharmacotherapy of nicotine addiction, including nicotine nasal spray, nicotine inhaler, bupropion hydrochloride, and over-the-counter transdermal nicotine patches, have increased the treatment options physicians can offer to smokers. Physicians, especially those in primary care specialties, should familiarize themselves with these products to improve efforts to help their patients stop smoking. This article reviews scientific data on the efficacy of approved medications, benefits, adverse effects, and appropriate use of these products. We also discuss nicotine addiction and treatment for special populations, including women, ethnic minorities, light smokers, and patients with cardiovascular and pulmonary diseases.

Documentation of smoking: role of age, gender, and ethnicity.

This study assessed the role of age, gender, and ethnicity in chart documentation of smoking by primary care providers. Clinic patients (n = 304) were asked their smoking status and medical records were reviewed. Twenty-nine percent of reviewed patients were smokers, 27.6% former smokers, and 43.1% nonsmokers. Providers were more likely to document smoking among males (OR = 4.6; 95% CI = 2.2-9.5), middle-aged patients (OR = 4.0; 95% CI = 1.4-11.0), and smokers (OR = 8.1; 95% CI = 4.1-16.0). Data revealed selective documentation of smoking in males and middle-aged patients by providers, suggesting gender and age bias in the recognition and documentation of this risky behavior. We conclude that providers should screen for smoking in all patients regardless of age or gender.

Differences among African American light, moderate, and heavy smokers.

This study examined differences in demography, behavior, attitude, and physician intervention among African American light, moderate, and heavy smokers. Data were derived from an intervention study designed to assess whether a smoking status stamp would increase screening for smoking status and cessation counseling by physicians. Current analysis included 879 African American smokers categorized into three groups: light (<10 cigarettes/day), moderate (10-19 cigarettes/day), or heavy (> or =20 cigarettes/day) smokers based on number of cigarettes per day smoked. Light smokers constituted 40% of study sample, 33% were moderate smokers, and 27% were heavy smokers. Light smokers were more likely to be female (p<0.001) and have a shorter smoking history (p<0.001). Light smokers were not different in age (p=0.334), or the number of previous quit attempts (p=0.551). Although light smokers were more likely than moderate and heavy smokers to be preparing to quit (p<0.001), they were less likely to be asked their smoking status (p=0.031) or told to arrange follow-up for smoking cessation (p=0.034) by their physicians. Many African American smokers are light smokers. Light smokers are more likely to be female and have a shorter smoking history. Despite their readiness to quit, compared to heavier smokers, African American light smokers are asked about smoking less often by their physicians. Programs are needed to enhance physician intervention in this understudied population of smokers.