Factors associated with study attrition in a pilot randomised controlled trial to explore the role of exercise-assisted reduction to stop (EARS) smoking in disadvantaged groups

Abstract

BackgroundStudy attrition has the potential to compromise a trial’s internal and external validity. The aim of the present study was to identify factors associated with participant attrition in a pilot trial of the effectiveness of a novel behavioural support intervention focused on increasing physical activity to reduce smoking, to inform the methods to reduce attrition in a definitive trial.MethodsDisadvantaged smokers who wanted to reduce but not quit were randomised (N = 99), of whom 61 (62 %) completed follow-up assessments at 16 weeks. Univariable logistic regression was conducted to determine the effects of intervention arm, method of recruitment, and participant characteristics (sociodemographic factors, and lifestyle, behavioural and attitudinal characteristics) on attrition, followed by multivariable logistic regression on those factors found to be related to attrition.ResultsParticipants with low confidence to quit, and who were undertaking less than 150 mins of moderate and vigorous physical activity per week at baseline were less likely to complete the 16-week follow-up assessment. Exploratory analysis revealed that those who were lost to follow-up early in the trial (i.e., by 4 weeks), compared with those completing the study, were younger, had smoked for fewer years and had lower confidence to quit in the next 6 months. Participants who recorded a higher expired air carbon monoxide reading at baseline were more likely to drop out late in the study, as were those recruited via follow-up telephone calls. Multivariable analyses showed that only completing less than 150 mins of physical activity retained any confidence in predicting attrition in the presence of other variables.ConclusionsThe findings indicate that those who take more effort to be recruited, are younger, are heavier smokers, have less confidence to quit, and are less physically active are more likely to withdraw or be lost to follow-up.

Factors associated with retention in a smoking cessation trial for persons with a mental illness: a descriptive study

“…The finding that participation in prior follow-up assessments increased the likelihood of retention at the final assessment is supportive of prior research suggesting maintenance of contact with participants across the follow-up period facilitates retention [33, 50, 51]. Such results suggest that intermediate follow-up assessments not only provide extended behaviour-change data, but serve as a trial design strategy to improve retention at the primary follow-up point.…”

Rates of retention of persons with a mental health disorder in outpatient smoking cessation and reduction trials, and associated factors: protocol for a systematic review and meta-analysis

“…Illustrating a consensus regarding the need to consider and address the issue of low retention in clinical and health behaviour trials: the inclusion of items on participant retention in the Consolidated Standards of Reporting Trials (CONSORT) statement,28 29 and prioritisation of trial methodology research to develop novel approaches to increase retention in randomised trials 30 31. In addition, the emergence of recent systematic reviews examining retention rates in health behaviour studies32–36 and publication of retention data from high quality randomised trials37–39 indicates increased interest in the topic of retention and a recognition of its importance.…”

Impact of a pharmacy-led smoking cessation clinic in a dermatology centre

“…Previous studies have found several factors to be associated with lower attrition rates, including older participant age, being followed up by telephone call, smoking relapse or failure to reduce smoking levels. (11) To reduce dropout rates in future studies, strategies to engage younger participants should be followed and reassurances given to participants that smoking behaviour should not influence ongoing participation in the study. (11) When participants are followed up by telephone calls, researchers should work flexible hours, so that those who are employed can be contacted during regular working hours.…”

“…(11) To reduce dropout rates in future studies, strategies to engage younger participants should be followed and reassurances given to participants that smoking behaviour should not influence ongoing participation in the study. (11) When participants are followed up by telephone calls, researchers should work flexible hours, so that those who are employed can be contacted during regular working hours. (11) At our centre, we have reduced fees for follow-up appointments to reduce the financial load.…”

“…(11) When participants are followed up by telephone calls, researchers should work flexible hours, so that those who are employed can be contacted during regular working hours. (11) At our centre, we have reduced fees for follow-up appointments to reduce the financial load. In our study, participants commencing the programme were counselled that attending at least one follow-up was mandatory.…”