Department of Family Medicine, University of Wisconsin, Madison, Wisconsin 53715, USA.
Ann Intern Med. 2010 Dec 21;153(12):769-77. doi: 10.7326/0003-4819-153-12-201012210-00003.
Echinacea is widely used to treat the common cold.
To assess the potential benefits of echinacea as a treatment of common cold.
Randomized, controlled trial. (ClinicalTrials.gov registration number: NCT00065715)
Dane County, Wisconsin.
719 patients, aged 12 to 80 years, with new-onset common cold.
Patients were assigned to 1 of 4 parallel groups: no pills, placebo pills (blinded), echinacea pills (blinded), or echinacea pills (unblinded, open-label). Echinacea groups received the equivalent of 10.2 g of dried echinacea root during the first 24 hours and 5.1 g during each of the next 4 days. Indistinguishable placebo tablets contained only inert ingredients.
The primary outcome was the area under the curve for global severity, with severity assessed twice daily by self-report using the Wisconsin Upper Respiratory Symptom Survey, short version. Secondary outcomes included interleukin-8 levels and neutrophil counts from nasal wash, assessed at intake and 2 days later.
Of the 719 patients enrolled, 713 completed the protocol. Mean age was 33.7 years, 64% were female, and 88% were white. Mean global severity was 236 and 258 for the blinded and unblinded echinacea groups, respectively; 264 for the blinded placebo group; and 286 for the no-pill group. A comparison of the 2 blinded groups showed a 28-point trend (95% CI, -69 to 13 points) toward benefit for echinacea (P = 0.089). Mean illness duration in the blinded and unblinded echinacea groups was 6.34 and 6.76 days, respectively, compared with 6.87 days in the blinded placebo group and 7.03 days in the no-pill group. A comparison of the blinded groups showed a nonsignificant 0.53-day (CI, -1.25 to 0.19 days) benefit (P = 0.075). Median change in interleukin-8 levels and neutrophil counts were also not statistically significant (30 ng/L and 1 cell/high-power field [hpf] in the no-pill group, 39 ng/L and 1 cell/hpf in the blinded placebo group, 58 ng/L and 2 cells/hpf in the blinded echinacea group, and 70 ng/L and 1 cell/hpf in the open-label echinacea group).
Higher-than-expected variability limited power to detect small benefits.
Illness duration and severity were not statistically significant with echinacea compared with placebo. These results do not support the ability of this dose of the echinacea formulation to substantively change the course of the common cold.
National Center for Complementary and Alternative Medicine, National Institutes of Health.
紫锥菊被广泛用于治疗普通感冒。
评估紫锥菊作为普通感冒治疗方法的潜在益处。
随机对照试验。（临床试验.gov 注册号：NCT00065715）
威斯康星州戴恩县。
719 名年龄在 12 至 80 岁之间、新发普通感冒的患者。
患者被分配到 4 个平行组中的 1 个：无药丸、安慰剂药丸（盲法）、紫锥菊药丸（盲法）或紫锥菊药丸（非盲法、开放标签）。紫锥菊组在最初 24 小时内接受相当于 10.2 克干紫锥菊根的剂量，接下来的 4 天内每天接受 5.1 克。外观相同的安慰剂片剂仅含有惰性成分。
主要结局是全球严重程度的曲线下面积，严重程度通过自我报告使用威斯康星州上呼吸道症状调查（短版）每天两次进行评估。次要结局包括白细胞介素-8 水平和鼻腔冲洗后的中性粒细胞计数，在摄入和 2 天后进行评估。
在纳入的 719 名患者中，713 名完成了方案。平均年龄为 33.7 岁，64%为女性，88%为白人。盲法和非盲法紫锥菊组的平均全球严重程度分别为 236 和 258；盲法安慰剂组为 264；无药丸组为 286。比较两组盲法发现，紫锥菊有 28 分的趋势（95%CI，-69 至 13 分）（P = 0.089）。盲法和非盲法紫锥菊组的平均疾病持续时间分别为 6.34 天和 6.76 天，而盲法安慰剂组为 6.87 天，无药丸组为 7.03 天。比较两组盲法发现，紫锥菊有 0.53 天（CI，-1.25 至 0.19 天）的非显著益处（P = 0.075）。白细胞介素-8 水平和中性粒细胞计数的中位数变化也没有统计学意义（无药丸组为 30ng/L 和 1 个高倍视野[hpf]，盲法安慰剂组为 39ng/L 和 1 个 hpf，盲法紫锥菊组为 58ng/L 和 2 个 hpf，开放标签紫锥菊组为 70ng/L 和 1 个 hpf）。
高于预期的变异性限制了检测小益处的能力。
与安慰剂相比，紫锥菊对疾病持续时间和严重程度没有统计学意义。这些结果不支持这种剂量的紫锥菊配方能够实质性地改变普通感冒的病程。
国家补充和替代医学中心，美国国立卫生研究院。
