Gallo C, Perrone F, De Placido S, Giusti C
Cattedra di Statistica Medica e Biometria, Facoltà di Medicina e Chirurgia, Seconda Università di Napoli, Italy.
Lancet. 1995 Oct 21;346(8982):1060-4. doi: 10.1016/s0140-6736(95)91741-1.
We compared different procedures for seeking consent to participate in a sham randomised clinical trial and assessed whether refusal is affected by awareness of the severity of outlook. 2035 healthy subjects aged between 20 and 80 years, who visited a scientific exhibition, were enrolled in a hypothetical trial of experimental versus standard therapy, and randomly assigned to groups asked for conventional informed consent or prerandomisation consent. There were four study groups: one-sided informed consent for randomisation (subjects who refused would receive standard treatment); two-sided informed consent for randomisation (subjects who refused could choose between standard and experimental treatment); randomised consent to experimental treatment (subjects who refused would receive standard treatment); and randomised consent to standard treatment (subjects who refused would receive experimental treatment). The refusal rates were 16.2%, 19.9%, 12.1%, and 49.2%, respectively. The perceived severity of the simulated disease affected the refusal rate: the worse the outlook, the lower the refusal rate for informed consent or for consent after randomisation to new treatment, and the higher the refusal rate for consent after randomisation to standard treatment. The prerandomisation design seems to be efficient in a one-sided clinical scenario (eg, a trial of a new drug that would not be given outside the trial) because the refusal rate was substantially lower for prerandomisation to the new treatment than for conventional one-sided informed consent. However, in a two-sided clinical scenario (eg, a trial comparing similar treatments) the prerandomisation design is potentially highly inefficient; the refusal rate was much higher for prerandomisation to standard treatment than for conventional two-sided informed consent.
我们比较了在一项假随机临床试验中寻求参与同意的不同程序，并评估了拒绝是否受对预后严重性认知的影响。2035名年龄在20至80岁之间、参观科学展览的健康受试者被纳入一项关于实验性治疗与标准治疗的假设性试验，并被随机分配到要求获得传统知情同意或随机化前同意的组中。共有四个研究组：随机化的单侧知情同意（拒绝的受试者将接受标准治疗）；随机化的双侧知情同意（拒绝的受试者可在标准治疗和实验性治疗之间选择）；对实验性治疗的随机同意（拒绝的受试者将接受标准治疗）；以及对标准治疗的随机同意（拒绝的受试者将接受实验性治疗）。拒绝率分别为16.2%、19.9%、12.1%和49.2%。对模拟疾病感知的严重性影响了拒绝率：预后越差，对知情同意或随机化后接受新治疗的同意的拒绝率越低，而对随机化后接受标准治疗的同意的拒绝率越高。在单侧临床场景（例如，一种不在试验外给予的新药的试验）中，随机化前设计似乎是有效的，因为随机化前接受新治疗的拒绝率远低于传统的单侧知情同意。然而，在双侧临床场景（例如，比较相似治疗的试验）中，随机化前设计可能效率极低；随机化前接受标准治疗的拒绝率远高于传统的双侧知情同意。
