Carvalho Sandra, Leite Jorge, Jones Felipe, Morse Leslie R, Zafonte Ross, Fregni Felipe
Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.
Neuropsychophysiology Laboratory, CiPsi, School of Psychology, University of Minho, Campus de Gualtar, Braga, Portugal.
Spinal Cord. 2018 May;56(5):502-508. doi: 10.1038/s41393-017-0023-5. Epub 2017 Dec 13.
Secondary analysis of a clinical trial.
To analyze adherence to 1-year transcranial Direct Current Stimulation (tDCS) clinical trial in people with chronic pain due to spinal cord injury (SCI). We also explore the association between dropout and several baseline variables such as age, depression levels, pain severity, number of days with pain in the last 7 days, walking ability, sleep, work, relationship with others, and enjoyment with life.
Boston, USA.
Forty-six participants were enrolled in this trial, and 33 participants were randomized to receive either active or sham tDCS.
Using the full intention-to-treat (ITT) criteria, only 8 participants (24%) finished the study. The median time to dropout was seven (IQR:6,19) sessions (i.e., immediately after the first follow-up), regardless of the type of stimulation that participants received (active vs. sham tDCS) (χ2 = 0.025, p = 0.875). An exploratory analysis suggested that only the number of days with pain in the last 7 days was moderately associated with dropout, with people experiencing less pain being more prone to dropout from the study.
Despite all the measures to improve study adherence (such as providing parking, flexibility to schedule sessions, follow-up with participants by phone), it seems that long follow-up periods may increase the likelihood of dropout. Given the need to understand long-term effects of interventions, longitudinal trials need to consider alternative designs or methods of treatment (for instance home treatment or home assessment) to decrease attrition rate.
一项临床试验的二次分析。
分析脊髓损伤（SCI）所致慢性疼痛患者对为期1年的经颅直流电刺激（tDCS）临床试验的依从性。我们还探讨了退出试验与几个基线变量之间的关联，这些变量包括年龄、抑郁水平、疼痛严重程度、过去7天的疼痛天数、行走能力、睡眠、工作、与他人的关系以及生活乐趣。
美国波士顿。
46名参与者纳入本试验，33名参与者被随机分配接受主动或假tDCS治疗。
采用全意向性分析（ITT）标准，仅有8名参与者（24%）完成了研究。无论参与者接受何种刺激类型（主动tDCS与假tDCS），退出试验的中位时间为7次（四分位间距：6,19）治疗（即首次随访后立即退出）（χ2 = 0.025，p = 0.875）。一项探索性分析表明，仅过去7天的疼痛天数与退出试验有中度关联，疼痛较轻的人更易退出研究。
尽管采取了所有提高研究依从性的措施（如提供停车位、灵活安排治疗时间、通过电话对参与者进行随访），但似乎较长的随访期可能会增加退出试验的可能性。鉴于需要了解干预措施的长期效果，纵向试验需要考虑采用替代设计或治疗方法（如家庭治疗或家庭评估）以降低失访率。
