Validating Use of Internet-Submitted Carbon Monoxide Values by Video to Determine Quit Status

Reintroducing face-to-face support alongside remote support to form a hybrid stop smoking service in England: a formative mixed methods evaluation

BACKGROUND

During the COVID-19 pandemic, United Kingdom (UK) stop smoking services had to shift to remote delivery models due to social distancing regulations, later reintroducing face-to-face provision. The "Living Well Smokefree" service in North Yorkshire County Council adopted a hybrid model offering face-to-face, remote, or a mix of both. This evaluation aimed to assess the hybrid approach's strengths and weaknesses and explore potential improvements.

METHODS

Conducted from September 2022 to February 2023, the evaluation consisted of three components. First, qualitative interviews involved 11 staff and 16 service users, analysed thematically. Second, quantitative data from the QuitManager system that monitored the numbers and proportions of individuals selecting and successfully completing a 4-week quit via each service option. Third, face-to-face service expenses data was used to estimate the value for money of additional face-to-face provision. The qualitative findings were used to give context to the quantitative data via an "expansion" approach and complementary analysis.

RESULTS

Overall, a hybrid model was seen to provide convenience and flexible options for support. In the evaluation, 733 individuals accessed the service, with 91.3% selecting remote support, 6.1% face-to-face, and 2.6% mixed provision. Remote support was valued by service users and staff for promoting openness, privacy, and reducing stigma, and was noted as removing access barriers and improving service availability. However, the absence of carbon monoxide monitoring in remote support raised accountability concerns. The trade-off in "quantity vs. quality" of quits was debated, as remote support reached more users but produced fewer carbon monoxide-validated quits. Primarily offering remote support could lead to substantial workloads, as staff often extend their roles to include social/mental health support, which was sometimes emotionally challenging. Offering service users a choice of support options was considered more important than the "cost-per-quit". Improved dissemination of information to support service users in understanding their options for support was suggested.

CONCLUSIONS

The hybrid approach allows smoking cessation services to evaluate which groups benefit from remote, face-to-face, or mixed options and allocate resources accordingly. Providing choice, flexible provision, non-judgmental support, and clear information about available options could improve engagement and match support to individual needs, enhancing outcomes.

A Scoping Review and Meta-analysis of the Use of Remote Biochemical Verification Methods of Smoking Status in Tobacco Research

INTRODUCTION

Increasing digital delivery of smoking cessation interventions has resulted in the need to employ novel strategies for remote biochemical verification.

AIMS AND METHODS

This scoping review and meta-analysis aimed to investigate best practices for remote biochemical verification of smoking status. The scientific literature was searched for studies that reported remotely obtained (not in-person) biochemical confirmation of smoking status (ie, combustible tobacco). A meta-analysis of proportions was conducted to investigate key outcomes, which included rates of returned biological samples and the ratio of biochemically verified to self-reported abstinence rates.

RESULTS

A total of 82 studies were included. The most common samples were expired air (46%) and saliva (40% of studies), the most common biomarkers were carbon monoxide (48%) and cotinine (44%), and the most common verification methods were video confirmation (37%) and mail-in samples for lab analysis (26%). Mean sample return rates determined by random-effects meta-analysis were 70% for smoking cessation intervention studies without contingency management (CM), 77% for CM studies, and 65% for other studies (eg, feasibility and secondary analyses). Among smoking cessation intervention studies without CM, self-reported abstinence rates were 21%, biochemically verified abstinence rates were 10%, and 47% of individuals who self-reported abstinence were also biochemically confirmed as abstinent.

CONCLUSIONS

This scoping review suggests that improvements in sample return rates in remote biochemical verification studies of smoking status are needed. Recommendations for reporting standards are provided that may enhance confidence in the validity of reported abstinence rates in remote studies.

IMPLICATIONS

This scoping review and meta-analysis included studies using remote biochemical verification to determine smoking status. Challenges exist regarding implementation and ensuring high sample return rates. Higher self-reported compared to biochemically verified abstinence rates suggest the possibility that participants in remote studies may be misreporting abstinence or not returning samples for other reasons (eg, participant burden, inconvenience). Remote biochemical confirmation of self-reported smoking abstinence should be included in smoking cessation studies whenever feasible. However, findings should be considered in the context of challenges to sample return rates. Better reporting guidelines for future studies in this area are needed.

Mobile, Remote, and Individual Focused: Comparing Breath Carbon Monoxide Readings and Abstinence Between Smartphone-Enabled and Stand-Alone Monitors

INTRODUCTION

Newly available, smartphone-enabled carbon monoxide (CO) monitors are lower in cost than traditional stand-alone monitors and represent a marked advancement for smoking research. New products are promising, but data are needed to compare breath CO readings between smartphone-enabled and stand-alone monitors. The purpose of this study was to (1) determine the agreement between the mobile iCO (Bedfont Scientific Ltd) with two other monitors from the same manufacturer (Micro+ pro and Micro+ basic) and (2) determine optimal, monitor-specific, cotinine-confirmed abstinence cutoff values.

METHODS

Adult (≥18) smokers (n = 26) and nonsmokers (n = 21) provided three breath CO samples (using three different monitors) in each of 10 sessions, and urine cotinine was measured for gold standard determination of abstinence. CO comparisons (N = 437) were analyzed using regression-based Bland-Altman Analysis of Agreement; receiver operating characteristics curves were used to determine optimal abstinence cutoffs.

RESULTS

Bland-Altman analyses indicated that the iCO monitor provided higher CO results than both Micro+ monitors. Sensitivity and specificity analyses showed that the optimal CO cutoff for determining abstinence was <3 ppm for the Micro+ pro (88% sensitivity, 93% specificity) and Micro+ basic (83% sensitivity, 98% specificity), but was higher for the iCO (<6 ppm; 73% sensitivity, 100% specificity).

CONCLUSIONS

Relative to both Micro+ monitors, the smartphone-enabled iCO provided systematically higher CO values and required a higher cutoff to reliably determine smoking abstinence. This does not indicate that CO values obtained using the iCO are not valid; instead, these results suggest that monitor-specific abstinence cutoffs are needed to ensure accurate bioverification of smoking status.

IMPLICATIONS

Results from this study indicate that CO values from the smartphone-enabled iCO should not be used interchangeably with the stand-alone Micro+ pro and Micro+ basic, particularly when lower CO values (<10 ppm) are critical (ie, determination of abstinence vs confirming smoking status for study inclusion). Optimal CO cutoffs recommended for determining abstinence on Micro+ and iCO monitors are at <3 and <6 ppm, respectively.

Determining Optimal Cutoffs for Exhaled Carbon Monoxide and Salivary Cotinine to Identify Smokers among Korean Americans in a Smoking Cessation Clinical Trial

Introduction

It is critical to accurately identify individuals who continue to smoke even after treatment, as this may prompt the use of more intensive and effective treatment strategies to help them attain complete abstinence.

Aims

This study examined optimal cutoffs for exhaled carbon monoxide (CO) and salivary cotinine to identify smokers among Korean Americans in a smoking cessation clinical trial.

Methods

CO and cotinine were measured three to four times over 12 months from the quit day. Statistical analysis was conducted using Receiver Operating Characteristic (ROC) curves.

Results

A CO cutoff of 5 parts per million provided robust sensitivity (80.8-98.3%) and perfect specificity (100%), and a salivary cotinine cutoff of level 2 (30-100 ng/ml) provided the best sensitivity (91.2-95.6%) and perfect specificity (100%). Using these cutoffs, the agreement between self-reports and the two biomarkers ranged from 88.6% to 97.7%. The areas under ROC curves (AUCs) of exhaled CO ranged from 0.90 to 0.99, all of which were significant (all p values < 0.001), and the AUCs of salivary cotinine ranged from 0.96 to 0.98 (all p values < 0.001).

Conclusion

Exhaled CO and salivary cotinine are complementary, and they should be used together to verify smoking abstinence for smokers in a clinical trial.

Very Light Daily Smoking in Young Adults: Relationships Between Nicotine Dependence and Lapse

INTRODUCTION

Very light daily smoking is increasingly common among young adults. Evidence suggests that levels of nicotine dependence vary significantly among young adults who engage in very light daily smoking. However, the links between dependence and clinically relevant outcomes (eg, lapse) in this population remain unclear. The goal of this study was to address this gap by evaluating how well different nicotine dependence scales predict lapse behavior among very light daily smoking young adults.

AIMS AND METHODS

Very light daily smokers (1-5 cigarettes/day) aged 18-25 participated in an initial laboratory session, during which nicotine dependence was assessed using four commonly used measures: the Fagerstrӧm Test for Cigarette Dependence (FTCD), the Hooked On Nicotine Checklist (HONC), the Transdisciplinary Tobacco Use Research Centers (TTURC) Nicotine Dependence Inventory, and the Wisconsin Inventory of Smoking Dependence Motives (WISDM). After a baseline period, eligible participants (n = 40) completed a 10-day abstinence incentive period in which they attempted to refrain from smoking to earn monetary rewards. Cox proportional hazards models were used to test whether dependence predicted days to first lapse.

RESULTS

FTCD scores significantly predicted days to lapse, as did scores on the FTCD item assessing time to first cigarette of the day (TTFC). No other dependence measures predicted time to lapse. Both the FTCD and TTFC continued to independently predict time to lapse after controlling for smoking frequency and duration.

CONCLUSIONS

The FTCD may be a particularly useful tool for capturing clinically meaningful variability in nicotine dependence among young adults who engage in very light daily smoking.

IMPLICATIONS

This is the first study to directly link self-reported nicotine dependence with the ability to achieve and maintain abstinence among very light daily smoking young adults. The results may aid clinicians in selecting among variable measures of nicotine dependence when assessing and treating this population.

A Procedure to Standardize Puff Topography During Evaluations of Acute Tobacco or Electronic Cigarette Exposure

INTRODUCTION

Documenting factors that influence differential sensitivity to acutely inhaled nicotine products requires carefully controlling the amount of exposure (dose), and thus a procedure by which to control such exposure.

METHODS

We evaluated consistency of puff volume from intermittent acute exposures to smoked tobacco cigarettes (study 1, n = 45, plus a comparison study of uninstructed use with n = 59) and to vaped electronic cigarettes (e-cigarettes; study 2, n = 27 naive to e-cigarettes) in adult-dependent smokers. All in primary studies 1 and 2 participated in research administering different nicotine levels in each product under blind conditions, one per session using within-subject designs. In both studies, participants followed an automated instructional procedure on a computer monitor standardizing the timing and amount of exposure to each product during a given trial, with four trials per session, each separated by 20 minutes. Puff volume per trial via Clinical Research Support System (CReSS) was the primary dependent measure to determine consistency across trials via intraclass correlation coefficients (ICCs).

RESULTS

Control over topography with both inhaled products was demonstrated by highly significant ICCs for puff volume across trials. Instructed control with own brand was generally better in study 1 than with uninstructed smoking in the comparison sample, as expected. As intended, reliability of puff volume generally did not differ by menthol preference or sex in either study, but ICCs in study 2 tended to be lower for some men using the placebo e-cigarette.

CONCLUSIONS

This instructional procedure may substantially improve control over amounts of acute exposure to tobacco or e-cigarette use.

IMPLICATIONS

Control over topography in studies of acute exposure to these inhaled products can potentially aid validity of research into differential sensitivity to use, so findings can be attributed to factors of interest and not to variable exposure. Our procedure minimized variability in exposure to the same product and between moderate nicotine products, but remaining differences suggest that compensation for very low or no nicotine commercial products may be difficult to totally eliminate with these instructions alone. Further study is needed to determine this procedure's utility with other inhaled products among experienced users and when comparing different products in between-groups analyses.

A randomized controlled trial of a smoking cessation smartphone application with a carbon monoxide checker

Evidence of the long-term efficacy of digital therapies for smoking cessation that include a smartphone application (app) is limited. In this multi-center randomized controlled trial, we tested the efficacy of a novel digital therapy for smoking cessation: the "CureApp Smoking Cessation (CASC)" system, including a CASC smartphone app, a web-based patient management PC software for primary physicians, and a mobile exhaled carbon monoxide (CO) checker. A total of 584 participants with nicotine dependence were recruited from October 2017 to January 2018, and allocated 1:1 to the CASC intervention group or the control group. Both groups received a standard smoking cessation treatment with pharmacotherapy and counseling for 12 weeks. Meanwhile, the intervention group used the CASC system, and the control group used a control-app without a mobile CO checker, each for 24 weeks. The primary outcome was the biochemically validated continuous abstinence rate (CAR) from weeks 9 to 24. The main secondary outcome was an extended CAR from weeks 9 to 52. Except for 12 participants who did not download or use the apps, 285 participants were assigned to the intervention group, and 287, to the control. CAR from weeks 9 to 24 in the intervention group was significantly higher than that in the control group (63.9% vs. 50.5%; odds ratio [OR], 1.73; 95% confidence interval [CI], 1.24 to 2.42; P = 0.001). The CAR from weeks 9 to 52 was also higher in the intervention group than that in the control group (52.3% vs. 41.5%; OR, 1.55; 95% CI, 1.11 to 2.16; P = 0.010). No specific adverse events caused by the CASC system were reported. Augmenting standard face-to-face counseling and pharmacotherapy with a novel smartphone app, the CASC system significantly improved long-term CARs compared to standard treatment and a minimally supportive control app.

Lessons learned from unsuccessful use of personal carbon monoxide monitors to remotely assess abstinence in a pragmatic trial of a smartphone stop smoking app - A secondary analysis

INTRODUCTION

Verifying abstinence remotely in trials of digital cessation interventions remains a major challenge. This study reports on using personal carbon monoxide (CO) monitors to assess abstinence in a pragmatic trial of a standalone cessation app involving automated recruitment with no researcher contact.

METHODS

The study involved secondary data analysis of remote CO testing in a randomized trial (ISRCTN10548241) comparing two versions of a cessation app (BupaQuit). Trial participants were adult UK-based smokers interested in quitting, who were recruited online (02/2015-03/2016). Participants were followed-up through the app, email or phone at 4 weeks. Fifty-nine participants reporting not smoking were posted a personal CO monitor with instructions, and emailed two reminders. The monitors required installing software on a Windows PC. Participants were not reimbursed but retained the device. We recorded the proportion of CO tests returned, test results, self-reported ease of use, correct use, acceptability, and reasons for missing results.

RESULTS

Fifteen (25.4%) CO results were returned, of which 86.6% were <10 ppm and 53.3% were <5 ppm, indicating abstinence (corresponding to 20.9% and 12.9% of all trial participants self-reporting abstinence, respectively). These 15 participants found the test easy, acceptable and believed they conducted it correctly. Eight (18.2%) of the missing results were accounted for, including no access to a Windows PC, barriers to receiving packages, and unwillingness to share results.

CONCLUSION

Remote validation using personal CO monitors may not yet be feasible in pragmatic studies of cessation apps in which participants are recruited with no reimbursement or direct contact with researchers.

A novel and remote biochemical verification method of smoking abstinence: Predictors of participant compliance

INTRODUCTION

Biochemical verification of smoking abstinence remains an important validity check of cessation trial outcomes. Digital health trials rarely establish in-person contacts between participants and intervention providers, requiring novel strategies to biochemically verify outcomes. We describe remote verification of smoking abstinence via saliva cotinine and individual predictors of compliance in a digital intervention.

METHODS

Data came from a feasibility trial and randomized controlled trial of a Facebook smoking cessation intervention for young adults. In both trials, participants completed baseline and follow-up surveys at 3, 6 and 12 months. Participants indicating past 7-day point prevalence smoking abstinence were mailed a saliva cotinine kit. Participants were instructed to electronically send two photos - one of them giving a saliva sample and the other with the test results. We investigated predictors of compliance with these procedures, independent of verification results, among participants that were mailed a kit at any follow-up point (N=130; mean age = 21.3; 59.2% female) using logistic and multinomial regression.

RESULTS

A total of 189 kits were sent out, of which 97 were completed (51.3% compliance). We did not identify significant predictors of completing any vs no kits using logistic regression. We also found no significant predictors of extent of kit completion (none vs some; none vs all) using multinomial regression and controlling for number of kits sent.

CONCLUSIONS

Findings demonstrate the feasibility of this biochemical verification method and suggest low risk for bias of results. Future studies should replicate findings in larger samples and improve compliance with verification procedures.