Covariates of success in quitting smoking: a systematic review of studies from 2008 to 2021 conducted to inform the statistical analyses of quitting outcomes of a hospital-based tobacco dependence treatment service in the United Kingdom

Abstract

Background Smoking cessation interventions are being introduced into routine secondary care in the United Kingdom (UK), but there are person and setting-related factors that could moderate their success in quitting smoking. This review was conducted as part of an evaluation of the QUIT hospital-based tobacco dependence treatment service (https://sybics-quit.co.uk). The aim of the review was to identify a comprehensive set of variables associated with quitting success among tobacco smokers contacting secondary healthcare services in the UK who are offered support to quit smoking and subsequently set a quit date. The results would then be used to inform the development of a statistical analysis plan to investigate quitting outcomes. Methods Systematic literature review of five electronic databases. Studies eligible for inclusion investigated quitting success in one of three contexts: (a) the general population in the UK; (b) people with a mental health condition; (c) quit attempts initiated within a secondary care setting. The outcome measures were parameters from statistical analysis showing the effects of covariates on quitting success with a statistically significant (i.e., p-value <0.05) association. Results The review identified 29 relevant studies and 14 covariates of quitting success, which we grouped into four categories: demographics (age; sex; ethnicity; socio-economic conditions; relationship status, cohabitation and social network), individual health status and healthcare setting (physical health, mental health), tobacco smoking variables (current tobacco consumption, smoking history, nicotine dependence; motivation to quit; quitting history), and intervention characteristics (reduction in amount smoked prior to quitting, the nature of behavioural support, tobacco dependence treatment duration, pharmacological aids). Conclusions In total, 14 data fields were identified that should be considered for inclusion in datasets and statistical analysis plans for evaluating the quitting outcomes of smoking cessation interventions initiated in secondary care contexts in the UK. PROSPERO registration CRD42021254551 (13/05/2021)

Smoking Cessation after Transitioning from Hospital to Community Stop Smoking Services: Insights from Real-world Data Analysis

“…Our statistical analysis plan development was supported by a literature review to identify factors that might be associated with quitting outcomes. 30 Further details of population eligibility criteria and the covariates of interest were developed in the interim QUIT service evaluation report. 25 The evaluation team refined the analysis plan through regular discussions with the QUIT service team, including the programme director and manager, through the stages of evaluation planning, data collection, and data curation.…”

“…25 First, we conducted a literature review that was designed to identify factors that could be related to quitting outcomes. 30 Second, we cross-referenced the literature review’s suggested variables with the available CSSS data fields, which we grouped into four categories: “demographic and socio-economic factors”, “tobacco smoking factors”, “intervention characteristics” and “health and healthcare setting”. These categories are described below, with further details in the Supplementary Information.…”

“…While research has identified factors influencing quitting among smokers in general 37 and those receiving CSSS support, 38,39 there is limited evidence on how people's health and hospital contact types are associated with quitting outcomes. 30 Previous studies have suggested lower odds of quitting success for patients with higher cardiovascular risk, 25 more co-morbidities, 40 and certain mental health histories. [41][42][43] People referred to CSSS from hospital with poorer health status (e.g.…”