Predicting smoking cessation and its relapse in HIV-infected patients: the Swiss HIV Cohort Study

A new smoking cessation 'cascade' among women with or at risk for HIV infection

OBJECTIVES

The aim of this study was to define a smoking cessation 'cascade' among USA women with and without HIV and examine differences by sociodemographic characteristics.

DESIGN

An observational cohort study using data from smokers participating in the Women's Interagency HIV Study between 2014 and 2019.

METHODS

We followed 1165 women smokers with and without HIV from their first study visit in 2014 or 2015 until an attempt to quit smoking within approximately 3 years of follow-up, initial cessation (i.e. no restarting smoking within approximately 6 months of a quit attempt), and sustained cessation (i.e. no restarting smoking within approximately 12 months of a quit attempt). Using the Aalen-Johansen estimator, we estimated the cumulative probability of achieving each step, accounting for the competing risk of death.

RESULTS

Forty-five percent of smokers attempted to quit, 27% achieved initial cessation, and 14% achieved sustained cessation with no differences by HIV status. Women with some post-high school education were more likely to achieve each step than those with less education. Outcomes did not differ by race. Thirty-six percent [95% confidence interval (95% CI): 31-42] of uninsured women attempted to quit compared with 47% (95% CI: 44-50) with Medicaid and 49% (95% CI: 41-59) with private insurance.

CONCLUSION

To decrease smoking among USA women with and without HIV, targeted, multistage interventions, and increased insurance coverage are needed to address shortfalls along this cascade.

Risk for Non-AIDS-Defining and AIDS-Defining Cancer of Early Versus Delayed Initiation of Antiretroviral Therapy : A Multinational Prospective Cohort Study

BACKGROUND

Immediate initiation of antiretroviral therapy (ART) regardless of CD4 cell count reduces risk for AIDS and non-AIDS-related events in asymptomatic, HIV-positive persons and is the standard of care. However, most HIV-positive persons initiate ART when their CD4 count decreases below 500 × 10⁹ cells/L. Consequences of delayed ART on risk for non-AIDS-defining and AIDS-defining cancer, one of the most common reasons for death in HIV, are unclear.

OBJECTIVE

To estimate the long-term risk difference for cancer with the immediate ART strategy.

DESIGN

Multinational prospective cohort study.

SETTING

The D:A:D (Data collection on Adverse events of anti-HIV Drugs) study, which included HIV-positive persons from Europe, Australia, and the United States.

PARTICIPANTS

8318 HIV-positive persons with at least 1 measurement each of CD4 cell count and viral load while ART-naive (study period, 2006 to 2016).

MEASUREMENTS

The parametric g-formula was used, with adjustment for baseline and time-dependent confounders (CD4 cell count and viral load), to assess the 10-year risk for non-AIDS-defining and AIDS-defining cancer of immediate versus deferred (at CD4 counts <350 and <500 × 10⁹ cells/L) ART initiation strategies.

RESULTS

During 64 021 person-years of follow-up, 231 cases of non-AIDS-defining cancer and 272 of AIDS-defining cancer occurred among HIV-positive persons with a median age of 36 years (interquartile range, 29 to 43 years). With immediate ART, the 10-year risk for non-AIDS-defining cancer was 2.97% (95% CI, 2.37% to 3.50%) and that for AIDS-defining cancer was 2.50% (CI, 2.37% to 3.38%). Compared with immediate ART initiation, the 10-year absolute risk differences when deferring ART to CD4 counts less than 500 × 10⁹ cells/L and less than 350 × 10⁹ cells/L were 0.12 percentage point (CI, -0.01 to 0.26 percentage point) and 0.29 percentage point (CI, -0.03 to 0.73 percentage point), respectively, for non-AIDS-defining cancer and 0.32 percentage point (CI, 0.21 to 0.44 percentage point) and 1.00 percentage point (CI, 0.67 to 1.44 percentage points), respectively, for AIDS-defining cancer.

LIMITATION

Potential residual confounding due to observational study design.

CONCLUSION

In this young cohort, effects of immediate ART on 10-year risk for cancer were small, and further supportive data are needed for non-AIDS-defining cancer.

PRIMARY FUNDING SOURCE

Highly Active Antiretroviral Therapy Oversight Committee.

Impact of Smoking Cessation Interventions Initiated During Hospitalization Among HIV-Infected Smokers

INTRODUCTION

Smoking is a key determinant of mortality among people living with HIV (PLWH).

METHODS

To better understand the effects of smoking cessation interventions in PLWH, we conducted a pooled analysis of four randomized controlled trials of hospital-initiated smoking interventions conducted through the Consortium of Hospitals Advancing Research on Tobacco (CHART). In each study, cigarette smokers were randomly assigned to usual care or a smoking cessation intervention. The primary outcome was self-reported past 30-day tobacco abstinence at 6-month follow-up. Abstinence rates were compared between PLWH and participants without HIV and by treatment arm, using both complete-case and intention-to-treat analyses. Multivariable logistic regression was used to determine the effect of HIV status on 6-month tobacco abstinence and to determine predictors of smoking cessation within PLWH.

RESULTS

Among 5550 hospitalized smokers, there were 202 (3.6%) PLWH. PLWH smoked fewer cigarettes per day and were less likely to be planning to quit than smokers without HIV. At 6 months, cessation rates did not differ between intervention and control groups among PLWH (28.9% vs. 30.5%) or smokers without HIV (36.1% vs. 34.1%). In multivariable regression analysis, HIV status was not significantly associated with smoking cessation at 6 months. Among PLWH, confidence in quitting was the only clinical factor independently associated with smoking cessation (OR 2.0, 95% CI = 1.4 to 2.8, p < .01).

CONCLUSIONS

HIV status did not alter likelihood of quitting smoking after hospital discharge, whether or not the smoker was offered a tobacco cessation intervention, but power was limited to identify potentially important differences.

IMPLICATIONS

PLWH had similar quit rates to participants without HIV following a hospital-initiated smoking cessation intervention. The findings suggest that factors specific to HIV infection may not influence response to smoking cessation interventions and that all PLWH would benefit from efforts to assist in quitting smoking.

TRIAL REGISTRATION

(1) Using "warm handoffs" to link hospitalized smokers with tobacco treatment after discharge: study protocol of a randomized controlled trial: NCT01305928. (2) Web-based smoking cessation intervention that transitions from inpatient to outpatient: NCT01277250. (3) Effectiveness of smoking-cessation interventions for urban hospital patients: NCT01363245. (4) Effectiveness of Post-Discharge Strategies for Hospitalized Smokers (HelpingHAND2): NCT01714323.

Mental health disorders and alcohol use are associated with increased likelihood of smoking relapse among people living with HIV attending routine clinical care

BACKGROUND

People living with HIV (PLWH) have a high level of interest in quitting smoking, but only a small proportion have sustainable abstinence 6 months after cessation. Few investigations have focused on relapse to smoking among PLWH. In this investigation, we evaluated the prevalence of relapse after smoking cessation and the characteristics associated with smoking relapse using a retrospective, longitudinal cohort of PLWH during an eight-year observation.

METHODS

All patients aged ≥19 years that reported current smoking during the study period and then reported not smoking on a subsequent tobacco use questionnaire (quitters) were eligible for the study. In addition, patients required at least one subsequent follow-up visit after quitting where smoking status was again reported to allow for assessment of relapse. A Cox proportional hazard model was fit to evaluate factors associated with smoking relapse in PLWH attending routine clinical care.

RESULTS

Of the 473 patients who quit smoking in the study, 51% relapsed. In multivariable analysis, factors significantly associated with a higher likelihood of relapse were anxiety symptoms (HR = 1.55, 95% CI [1.11, 2.17]) and at-risk alcohol use (HR = 1.74, 95% CI [1.06, 2.85]), whereas antiretroviral therapy (ART) adherence (HR = 0.65, 95% CI [0.49, 0.99]) and longer time in care (HR = 0.94, 95% CI [0.91, 0.98]) were associated with a reduced likelihood of relapse after cessation.

CONCLUSION

Our study underscores the high prevalence of smoking relapse that exists among PLWH after they quit smoking. Successful engagement in mental health care may enhance efforts to reduce relapse in the underserved populations of PLWH.

Predictors of smoking cessation among people living with HIV receiving routine clinical care

People living with HIV (PLWH) have a higher prevalence of smoking and are less likely to quit smoking than the general population. Few studies involving a large sample of PLWH receiving routine care have evaluated factors associated with smoking cessation. This retrospective longitudinal cohort study evaluated factors associated with smoking cessation among PLWH from 2007 to 2018. Of 1,714 PLWH smokers included in the study, 27.6% reported quitting smoking. Suppressed plasma HIV-1 RNA (<200 copies/ml) was significantly associated with an increased likelihood of smoking cessation (HR_adjusted = 1.27, 95% CI [1.03, 1.58]); whereas age/10 year increments (HR_adjusted = 0.12, 95% CI [0.04, 0.38]), greater length of care at the HIV clinic (HR_adjusted = 0.97, 95% CI [0.94, 0.99]), lack of insurance (HR_adjusted = 0.77, 95% CI [0.61, 0.99]) or having public insurance (HR_adjusted = 0.74, 95% CI [0.55, 0.97)]), current substance use (HR_adjusted = 0.66, 95% CI [0.43, 0.97]) and risk of developing alcohol use disorder (HR_adjusted = 0.60, 95% CI [0.43, 0.84]) were associated with a reduced likelihood of quitting smoking. These findings underscore the importance of early smoking cessation intervention among PLWH. In addition, targeted smoking cessation intervention strategies are needed for groups at risk for being less likely to quit, including older patients, and those with alcohol and substance use disorders.

An Update on Statistical Boosting in Biomedicine

Statistical boosting algorithms have triggered a lot of research during the last decade. They combine a powerful machine learning approach with classical statistical modelling, offering various practical advantages like automated variable selection and implicit regularization of effect estimates. They are extremely flexible, as the underlying base-learners (regression functions defining the type of effect for the explanatory variables) can be combined with any kind of loss function (target function to be optimized, defining the type of regression setting). In this review article, we highlight the most recent methodological developments on statistical boosting regarding variable selection, functional regression, and advanced time-to-event modelling. Additionally, we provide a short overview on relevant applications of statistical boosting in biomedicine.

Sex Differences in Tobacco Use Among Persons Living With HIV/AIDS: A Systematic Review and Meta-Analysis

BACKGROUND

Persons living with HIV/AIDS (PLWH) smoke at higher rates than other adults and experience HIV-related and non-HIV-related adverse smoking consequences. This study conducted a systematic review to synthesize current knowledge about sex differences in smoking behaviors among PLWH.

METHODS

Over 3000 abstracts from MEDLINE were reviewed and 79 publications met all the review inclusion criteria (ie, reported data on smoking behaviors for PLWH by sex). Sufficient data were available to conduct a meta-analysis for one smoking variable: current smoking prevalence.

RESULTS

Across studies (n = 51), the meta-analytic prevalence of current smoking among female PLWH was 36.3% (95% confidence interval [CI]: 28.0% to 45.4%) and male PLWH was 50.3% (95% CI: 44.4% to 56.2%; meta-analytic odds ratio = 1.78, 95% CI: 1.29 to 2.45). When analyses were repeated just on the US studies (n = 23), the prevalence of current smoking was not significantly different for female PLWH (55.1%, 95% CI: 47.6% to 62.5%) compared with male PLWH (55.5%, 95% CI: 48.2% to 62.5%; meta-analytic odds ratio = 1.04, 95% CI: 0.86 to 1.26). Few studies reported data by sex for other smoking variables (eg, quit attempts, noncigarette tobacco product use) and results for many variables were mixed.

DISCUSSION

Unlike the general US population, there was no difference in smoking prevalence for female versus male PLWH (both >50%) indicating that HIV infection status was associated with a greater relative increase in smoking for women than men. More research is needed in all areas of smoking behavior of PLWH to understand similarities and differences by sex to provide the best interventions to reduce the high smoking prevalence for all sexes.

Exploring Issues of Comorbid Conditions in People Who Smoke

Smoking affects comorbid disease outcomes, and patients with comorbid conditions may have unique characteristics that are important to consider when treating tobacco use. However, addressing tobacco in patients being treated for comorbid conditions is not a consistent practice. Recognizing the need for a "call-to-action" to address tobacco use in people with comorbid conditions, the Tobacco Treatment Network within the Society for Research on Nicotine and Tobacco (SRNT) convened a Comorbidities Workgroup to explore the relationship between smoking and comorbid disease to identify common themes including: the harms associated with continued tobacco use, the frequency of comorbid disease and tobacco use, the potential effect of comorbid disease on the ability to quit tobacco use, the association between tobacco use and suboptimal disease-specific treatment response, and evidence regarding potential approaches to improve addressing tobacco use in patients with comorbid disease. Five candidate conditions (psychiatric, cancer, cardiovascular, pulmonary, and human immunodeficiency virus infected patients) were explored. Across comorbid conditions, smoking adversely affects treatment efficacy and promotes other adverse health conditions. People with comorbid conditions who smoke are motivated to quit and respond to evidence-based smoking cessation treatments. However, tobacco cessation is not regularly incorporated into the clinical care of many individuals with comorbidities. Optimal strategies for addressing tobacco use within each comorbid disease are also not well defined. Further work is needed to disseminate evidence-based care into clinical practice for smokers with comorbid disease and addiction research should consider comorbid conditions as an important construct to explore.

IMPLICATIONS

This article explores how physical and psychiatric conditions may interact in the treatment of tobacco dependence, and discusses the need for smoking cessation as a critical component of comorbid condition management. Five common comorbid domains-psychiatric, cancer, pulmonary, cardiovascular, and human immunodeficiency virus (HIV)-are highlighted to illustrate how these different conditions might interact with smoking with respect to prevalence and harm, motivation to quit, and cessation treatment utilization and success.

Motivation to quit smoking among HIV-positive smokers in Vietnam

BACKGROUND

Smoking cessation is emerging as an important component in current HIV care to reduce smoking-related adverse health outcomes. This study aimed to examine motivation to quit and its associated factors in a sample of 409 HIV-positive smokers in Vietnam.

METHODS

A cross-sectional survey was conducted from January to September 2013 in Hanoi (the capital) and Nam Dinh (a rural city). Motivation to quit was measured by a 4-point single item, and was dichotomized as having any motivation versus no motivation. Smoking history, nicotine dependence (Fagerstrom Test of Nicotine Dependence), and other covariates were self-reported by participants. Multivariate logistic regression was performed to identify correlates of motivation to quit.

RESULTS

The sample was mostly male (97%). Mean age was 36 years (SD = 5.8). Approximately 37% and 69% of the sample were hazardous drinkers and ever drug users, respectively. The mean duration of HIV infection and ART treatment were 6 years (SD = 3.6) and 5 years (SD = 2.2), respectively. Overall, 59% of the sample was motivated to quit. Factors significantly associated with motivation to quit were income, pain, currently taking Methadone, and the interaction between binge drinking and lifetime drug use. Individuals with the highest income level (OR = 2.2, 95% CI = 1.3-3.6), moderate income level (OR = 1.8, 95% CI = 1.1-3.1), and currently feeling pain (OR = 1.6, 95% CI = 1.0-2.5) were more likely to be motivated to quit. Conversely, taking Methadone was associated with a lower likelihood of motivation to quit (OR = 0.4, 95% CI = 0.2-0.9). Also, those who reported binge drinking only (OR = 0.5, 95% CI = 0.3-0.9), lifetime drug use only (OR = 0.3, 95% CI = 0.1, 0.7), or both substance uses (OR = 0.4, 95% CI = 0.2, 0.8) were less motivated to quit smoking.

CONCLUSION

Smoking cessation treatment should be integrated into HIV care in Vietnam, and should be tailored to meet specific needs for individuals with different attitudes on smoking, low income, and polysubstance use.

Myocardial infarction among Danish HIV-infected individuals: population-attributable fractions associated with smoking

BACKGROUND

Human immunodeficiency virus-infected individuals have increased risk of myocardial infarction (MI); however, the contribution from smoking and potentiating effects of HIV are controversial.

METHODS

From the Danish HIV Cohort Study and the Copenhagen General Population Study, we identified 3251 HIV-infected individuals and 13 004 population controls matched on age and gender. Data on MI were obtained from the National Hospital Registry and the National Registry of Causes of Death. We calculated adjusted incidence rate ratios (aIRR) for risk of MI and population-attributable fractions (PAF) of MI associated with smoking.

RESULTS

In never smokers, HIV was not associated with an increased risk of MI (aIRR, 1.01; 95% confidence interval [CI], .41-2.54). In previous and current smokers, HIV was associated with a substantially increased risk of MI (aIRR, 1.78; 95% CI, .75-4.24 and aIRR, 2.83; 95% CI, 1.71-4.70). The PAF associated with ever smoking (previous or current) was 72% (95% CI, 55%-82%) for HIV-infected individuals and 24% (95% CI, 3%-40%) for population controls. If all current smokers stopped smoking, 42% (95% CI, 21%-57%) and 21% (95% CI, 12%-28%) of all MIs could potentially be avoided in these 2 populations.

CONCLUSIONS

Smoking is associated with a higher risk of MI in the HIV-infected population than in the general population. Approximately 3 of 4 MIs among HIV-infected individuals are associated with ever smoking compared with only 1 of 4 MIs among population controls. Smoking cessation could potentially prevent more than 40% of MIs among HIV-infected individuals, and smoking cessation should be a primary focus in modern HIV care.