Psychology administration office, University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.
Hunter Medical Research Institute, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia.
BMC Med Res Methodol. 2018 Dec 27;18(1):177. doi: 10.1186/s12874-018-0640-5.
Exploring factors associated with retention in randomised trials provides insight into potential threats to internal and external study validity, and may inform the development of interventions to increase retention in future trials. Given a paucity of existing research in the field, a study was conducted to explore factors associated with retention in a smoking intervention trial involving persons with a mental illness, considering demographic and smoking characteristics, treatment condition and engagement in prior follow-up assessments.
A descriptive study was undertaken using data derived from a RCT of a smoking cessation intervention initiated in four adult psychiatric inpatient units in New South Wales (NSW), Australia. Retention assessment was undertaken at 1, 6 and 12-months post-discharge. A Generalised Linear Mixed Model was adopted to explore associations between retention at any follow up time point and demographic and smoking characteristics. Chi square analyses explored the association between retention at all follow up time points and treatment condition, and binary logistic regression analyses assessed for relationships between retention at 12-month follow up and engagement in prior follow up assessments.
Retention rates were 63, 56 and 60% at the 1, 6 and 12-month assessments, respectively. No association was found between retention at any follow-up time point and 13 of 15 demographic and smoking characteristics. Younger participants and those who identified to be Aboriginal and/or Torres Strait Islander were more likely to be retained (both ps > 0.05). Retention rates did not vary according to treatment condition at any follow-up time point. Participants who completed a prior assessment were more likely to complete the 12 month assessment (both prior assessments: OR 10.7, p < 0.001; 6 month assessment: OR 6.01, p < 0.001; and 1 month assessment: OR 1.8, p = 0.002).
The underrepresentation of younger participants and those identifying to be Aboriginal and/or Torres Strait Islander may limit the generalisability of findings. Findings suggest that inclusion of multiple contacts during a trial follow up period may increase retention at the final assessment. Interventions to improve retention, overall and for those sub-groups less likely to be retained, in smoking trials involving persons with a mental illness are needed. Further assessment of sample characteristics, and also trial design factors, associated with retention in this field is warranted.
探索与随机试验保留率相关的因素可以深入了解对内部和外部研究有效性的潜在威胁，并可能为未来试验中提高保留率的干预措施提供信息。鉴于该领域现有研究甚少，本研究旨在探讨与一项涉及精神疾病患者的戒烟干预试验保留率相关的因素，同时考虑人口统计学和吸烟特征、治疗条件以及先前随访评估的参与情况。
本研究采用描述性研究方法，利用澳大利亚新南威尔士州（NSW）四家成人精神病住院病房启动的一项戒烟干预随机对照试验（RCT）的数据。在出院后 1、6 和 12 个月进行保留率评估。采用广义线性混合模型探讨任何随访时间点的保留率与人口统计学和吸烟特征之间的关联。卡方分析探讨了所有随访时间点的保留率与治疗条件之间的关联，二元逻辑回归分析评估了 12 个月随访时的保留率与先前随访评估的参与情况之间的关系。
在 1、6 和 12 个月的评估中，保留率分别为 63%、56%和 60%。在任何随访时间点的保留率与 15 个人口统计学和吸烟特征中的 13 个均无关联。年轻参与者和自我认同为原住民和/或托雷斯海峡岛民的参与者更有可能被保留（两者 p 值均大于 0.05）。在任何随访时间点，治疗条件对保留率没有影响。完成先前评估的参与者更有可能完成 12 个月的评估（两项先前评估：OR 10.7，p<0.001；6 个月评估：OR 6.01，p<0.001；1 个月评估：OR 1.8，p=0.002）。
年轻参与者和自我认同为原住民和/或托雷斯海峡岛民的代表性不足可能限制研究结果的普遍性。研究结果表明，在试验随访期间纳入多次联系可能会提高最终评估的保留率。需要针对涉及精神疾病患者的戒烟试验中提高保留率的干预措施，包括总体和那些不太可能保留的亚组。需要进一步评估该领域与保留率相关的样本特征和试验设计因素。
