Turner Katrina M, Percival John, Kessler David, Donovan Jenny
School of Social and Community Medicine, University of Bristol, Bristol, UK.
The National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care West (NIHR CLAHRC West) at University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
Trials. 2017 Jun 15;18(1):279. doi: 10.1186/s13063-017-2030-4.
The way in which pragmatic trials are designed suggests that there are differences between the experiences of participants randomised to usual care and intervention arms. These potential differences relate not only to which treatment participants receive but also how they access and engage with their allocated treatment. Such differences could affect trial results. The aim of this study was to assess whether such differences exist and, if they do, to consider their implications for the design of future trials.
Interview transcripts were sampled from data sets gathered during three qualitative studies, all of which had been nested within large, primary care depression trials. Each study had explored trial participants' views and experiences of treatments received following randomisation. Transcripts from 37 participants were purposefully sampled, 20 of which were from interviews held with individuals allocated to receive usual GP care. Data were analysed thematically.
There was evidence of differences between trial arms across all three data sets. Intervention participants were willing and able to engage with the treatment to which they had been allocated. Randomisation had led to them embarking upon a clear treatment pathway and receiving care in a context where they felt comfortable discussing their mental health and had sufficient time to do so. Intervention participants also had continuity with and confidence in the practitioners they saw. A few usual-care participants talked about having continuity with and confidence in their GPs. However, most of the usual-care participants reported a reluctance to consult GPs about mental health, difficulties in securing treatment appointments, and little or no changes in care following randomisation. Additionally, most reported a lack of continuity of care and a lack confidence in the treatment available to them.
There are important differences between usual-care and intervention arms that go beyond treatment received, and they relate to how participants experience accessing and engaging with their allocated care. As these differences could affect trial results, researchers may want to measure or reduce them in order to fully appreciate or control for the range of factors that might affect treatment outcomes.
实用试验的设计方式表明，被随机分配到常规护理组和干预组的参与者的经历存在差异。这些潜在差异不仅与参与者接受的治疗有关，还与他们获取并参与所分配治疗的方式有关。此类差异可能会影响试验结果。本研究的目的是评估此类差异是否存在，若存在，则考虑其对未来试验设计的影响。
访谈记录取自三项定性研究收集的数据集，这三项研究均嵌套于大型初级保健抑郁症试验中。每项研究都探讨了试验参与者在随机分组后对所接受治疗的看法和体验。有目的地抽取了37名参与者的记录，其中20份来自对被分配接受全科医生常规护理的个体进行的访谈。对数据进行了主题分析。
在所有三个数据集中都有证据表明试验组之间存在差异。干预组参与者愿意并能够参与他们所分配的治疗。随机分组使他们走上了明确的治疗途径，并在一个他们感到自在讨论心理健康且有足够时间这样做的环境中接受护理。干预组参与者对他们所见到的从业者也有连续性和信心。一些常规护理组参与者谈到对他们的全科医生有连续性和信心。然而，大多数常规护理组参与者报告称不愿意就心理健康问题咨询全科医生，难以获得治疗预约，随机分组后护理几乎没有变化。此外，大多数人报告称护理缺乏连续性，对他们可获得的治疗缺乏信心。
常规护理组和干预组之间存在重要差异，这些差异超出了所接受的治疗，并且与参与者获取并参与所分配护理的体验有关。由于这些差异可能会影响试验结果，研究人员可能希望对其进行测量或减少，以便充分了解或控制可能影响治疗结果的各种因素。
