Centre for Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Southmead Hospital, North Bristol NHS Trust, Bristol, UK.
BMC Med Res Methodol. 2022 Feb 11;22(1):44. doi: 10.1186/s12874-021-01453-0.
Prospective cohort studies are challenging to deliver, with one of the main difficulties lying in retention of participants. The need to socially distance during the COVID-19 pandemic has added to this challenge. The pre-COVID-19 adaptation of the European Quality (EQUAL) study in the UK to a remote form of follow-up for efficiency provides lessons for those who are considering changing their study design.
The EQUAL study is an international prospective cohort study of patients ≥65 years of age with advanced chronic kidney disease. Initially, patients were invited to complete a questionnaire (SF-36, Dialysis Symptom Index and Renal Treatment Satisfaction Questionnaire) at research clinics every 3-6 months, known as "traditional follow-up" (TFU). In 2018, all living patients were invited to switch to "efficient follow-up" (EFU), which used an abbreviated questionnaire consisting of SF-12 and Dialysis Symptom Index. These were administered centrally by post. Response rates were calculated using returned questionnaires as a proportion of surviving invitees, and error rates presented as the average percentage of unanswered questions or unclear answers, of total questions in returned questionnaires. Response and error rates were calculated 6-monthly in TFU to allow comparisons with EFU.
Of the 504 patients initially recruited, 236 were still alive at the time of conversion to EFU; 111 of these (47%) consented to the change in follow-up. In those who consented, median TFU was 34 months, ranging from 0 to 42 months. Their response rates fell steadily from 88% (98/111) at month 0 of TFU, to 20% (3/15) at month 42. The response rate for the first EFU questionnaire was 60% (59/99) of those alive from TFU. With this improvement in response rates, the first EFU also lowered errors to baseline levels seen in early follow-up, after having almost trebled throughout traditional follow-up.
Overall, this study demonstrates that administration of shorter follow-up questionnaires by post rather than in person does not negatively impact patient response or error rates. These results may be reassuring for researchers who are trying to limit face-to-face contact with patients during the COVID-19 pandemic.
前瞻性队列研究具有挑战性，其中主要的困难之一在于参与者的保留率。在 COVID-19 大流行期间需要保持社交距离，这增加了这项挑战的难度。在 COVID-19 之前，英国的欧洲质量（EQUAL）研究对其进行了调整，以远程形式进行随访，以提高效率，这为那些正在考虑改变研究设计的人提供了经验教训。
EQUAL 研究是一项针对年龄≥65 岁、患有晚期慢性肾脏病的患者的国际前瞻性队列研究。最初，患者被邀请在研究诊所每 3-6 个月完成一份问卷（SF-36、透析症状指数和肾脏治疗满意度问卷），称为“传统随访”（TFU）。2018 年，所有在世的患者都被邀请转换为“高效随访”（EFU），后者使用由 SF-12 和透析症状指数组成的简化问卷。这些问卷通过邮寄进行集中管理。通过返回的问卷与幸存的受邀者的比例计算响应率，并通过返回问卷中未回答问题或不清楚答案的平均百分比呈现错误率，这些百分比是总问题数的一部分。TFU 中每 6 个月计算一次响应率和错误率，以便与 EFU 进行比较。
在最初招募的 504 名患者中，有 236 名患者在转换为 EFU 时仍存活；其中 111 名（47%）同意改变随访方式。在同意的患者中，中位 TFU 为 34 个月，范围为 0 至 42 个月。他们的响应率从 TFU 的第 0 个月的 88%（98/111）稳步下降到第 42 个月的 20%（3/15）。从 TFU 存活下来的人中，第一份 EFU 问卷的响应率为 60%（59/99）。随着响应率的提高，EFU 问卷的第一个问题的错误率也降低到了早期随访时的基线水平，而在传统随访中几乎增加了两倍。
总体而言，这项研究表明，通过邮寄而不是面对面的方式管理更简短的随访问卷不会对患者的响应率或错误率产生负面影响。这些结果可能会让那些在 COVID-19 大流行期间试图限制与患者面对面接触的研究人员感到放心。
