Use of the Smoking Cessation App Ex-Smokers iCoach and Associations With Smoking-Related Outcomes Over Time in a Large Sample of European Smokers: Retrospective Observational Study

BACKGROUND

Digital interventions are increasingly used to support smoking cessation. Ex-smokers iCoach was a widely available app for smoking cessation used by 404,551 European smokers between June 15, 2011, and June 21, 2013. This provides a unique opportunity to investigate the uptake of a freely available digital smoking cessation intervention and its effects on smoking-related outcomes.

OBJECTIVE

We aimed to investigate whether there were distinct trajectories of iCoach use, examine which baseline characteristics were associated with user groups (based on the intensity of use), and assess if and how these groups were associated with smoking-related outcomes.

METHODS

Analyses were performed using data from iCoach users registered between June 15, 2011, and June 21, 2013. Smoking-related data were collected at baseline and every 3 months thereafter, with a maximum of 8 follow-ups. First, group-based modeling was applied to detect distinct trajectories of app use. This was performed in a subset of steady users who had completed at least 1 follow-up measurement. Second, ordinal logistic regression was used to assess the baseline characteristics that were associated with user group membership. Finally, generalized estimating equations were used to examine the association between the user groups and smoking status, quitting stage, and self-efficacy over time.

RESULTS

Of the 311,567 iCoach users, a subset of 26,785 (8.6%) steady iCoach users were identified and categorized into 4 distinct user groups: low (n=17,422, 65.04%), mild (n=4088, 15.26%), moderate (n=4415, 16.48%), and intensive (n=860, 3.21%) users. Older users and users who found it important to quit smoking had higher odds of more intensive app use, whereas men, employed users, heavy smokers, and users with higher self-efficacy scores had lower odds of more intensive app use. User groups were significantly associated with subsequent smoking status, quitting stage, and self-efficacy over time. For all groups, over time, the probability of being a smoker decreased, whereas the probability of being in an improved quitting stage increased, as did the self-efficacy to quit smoking. For all outcomes, the greatest change was observed between baseline and the first follow-up at 3 months. In the intensive user group, the greatest change was seen between baseline and the 9-month follow-up, with the observed change declining gradually in moderate, mild, and low users.

CONCLUSIONS

In the subset of steady iCoach users, more intensive app use was associated with higher smoking cessation rates, increased quitting stage, and higher self-efficacy to quit smoking over time. These users seemed to benefit most from the app in the first 3 months of use. Women and older users were more likely to use the app more intensively. Additionally, users who found quitting difficult used the iCoach app more intensively and grew more confident in their ability to quit over time.

Smoking cessation strategy in the national cervical cancer screening program (SUCCESS): study protocol for a pragmatic cluster randomised trial and process evaluation in Dutch general practice

INTRODUCTION

Cervical cancer screening in general practice could be a routine moment to provide female smokers with stop smoking advice and support. The aim of this study is to assess the effect of a stop smoking strategy delivered by trained practice assistants after the cervical smear, and to evaluate the implementation process.

METHODS AND ANALYSIS

The study is a two-arm, pragmatic cluster randomised trial, in Dutch general practice. Randomisation takes place 1:1 at the level of the general practice. Practices either deliver the SUCCESS stop smoking strategy or the usual care condition. The strategy consists of brief stop smoking advice based on the Ask-Advise-Connect method and is conducted by trained practice assistants after routine cervical cancer screening. The primary outcome is the performance of a serious quit attempt in the 6 months after screening. Secondary outcomes are 7-day point prevalence abstinence, reduction in the number of cigarettes per day and transition in motivation to quit smoking. Follow-up for these measurements takes place after 6 months. Analysis on the primary outcome aims to detect a 10% difference between treatment arms (0.80 power, p=0.05, using a one-sided test), and will be performed according to the intention to treat principle. The process evaluation will assess feasibility, acceptability and barriers or enablers to the strategy's implementation. For this purpose, both qualitative and quantitative data will be collected via questionnaires and in-depth interviews, respectively, in both individual study participants and involved staff.

ETHICS AND DISSEMINATION

The Dutch Ministry of Health, Welfare and Sport approved of the trial after an advisory report from the Health Council (Nr. 2018/17). A licence was provided to conduct the study under the Population Screening Act. Study results will be disseminated through publications in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NL5052 (NTR7451).

Decompression sickness in caisson workers

El Ghawabi, S. H., Mansour, M. B., Youssef, F. L., El Ghawabi, M. H., and Abd El Latif, M. M. (1971).Brit. J. industr. Med.,28, 323-329. Decompression sickness in caisson workers. An investigation of 55 bridge construction workers is reported. The overall bends rate was 0·97%. (The term `bends' as used in this study is defined in the paper.) Chokes were encountered in 67·27% of workers. A clinical, haematological, and radiological study was performed.

Definite bony changes were found in 43·6% of all workers; 91·6% of these had lesions around the elbow. The presence of dense areas in the neck of the scapula is reported in two cases for the first time. The relatively high haematocrit value is thought to play a part in the pathogenesis of bone infarction through its relation with blood viscosity.