Barrett Bruce, Harahan Brian, Brown David, Zhang Zhengjun, Brown Roger
Department of Family Medicine, University of Wisconsin, Madison, Wisc 53715, USA.
Ann Fam Med. 2007 May-Jun;5(3):216-23. doi: 10.1370/afm.698.
We undertook a study to estimate the sufficiently important difference (SID) for the common cold. The SID is the smallest benefit that an intervention would require to justify costs and risks.
Benefit-harm tradeoff interviews (in-person and telephone) assessed SID in terms of overall severity reduction using evidence-based simple-language scenarios for 4 common cold treatments: vitamin C, the herbal medicine echinacea, zinc lozenges, and the unlicensed antiviral pleconaril.
Response patterns to the 4 scenarios in the telephone and in-person samples were not statistically distinguishable and were merged for most analyses. The scenario based on vitamin C led to a mean SID of 25% (95% confidence interval [CI] 0.23-0.27). For the echinacea-based scenario, mean SID was 32% (95% CI, 0.30-0.34). For the zinc-based scenario, mean SID was 47% (95% CI, 0.43-0.51). The scenario based on preliminary antiviral trials provided a mean SID of 57% (95% CI, 0.53-0.61). Multivariate analyses suggested that (1) between-scenario differences were substantive and reproducible in the 2 samples, (2) presence or severity of illness did not predict SID, and (3) SID was not influenced by age, sex, tobacco use, ethnicity, income, or education. Despite consistencies supporting the model and methods, response patterns were diverse, with wide spreads of individual SID values within and among treatment scenarios.
Depending on treatment specifics, people want an on-average 25% to 57% reduction in overall illness severity to justify costs and risks of popular cold treatments. Randomized trial evidence does not support benefits this large. This model and these methods should be further developed for use in other disease entities.
我们开展了一项研究，以估算普通感冒的足够重要差异（SID）。足够重要差异是指一种干预措施为证明成本和风险合理所需的最小益处。
利弊权衡访谈（面对面和电话访谈）使用基于证据的通俗易懂的情景，针对4种普通感冒治疗方法（维生素C、草药紫锥菊、锌含片和未经许可的抗病毒药物普来可那立），从总体严重程度降低方面评估了足够重要差异。
电话访谈样本和面对面访谈样本对4种情景的反应模式在统计学上无显著差异，大多数分析将二者合并。基于维生素C的情景得出的平均足够重要差异为25%（95%置信区间[CI]为0.23 - 0.27）。基于紫锥菊的情景，平均足够重要差异为32%（95% CI为0.30 - 0.34）。基于锌的情景，平均足够重要差异为47%（95% CI为0.43 - 0.51）。基于初步抗病毒试验的情景得出的平均足够重要差异为57%（95% CI为0.53 - 0.61）。多变量分析表明：（1）两种样本中各情景之间的差异是实质性的且可重复；（2）疾病的存在或严重程度不能预测足够重要差异；（3）足够重要差异不受年龄、性别、吸烟状况、种族、收入或教育程度的影响。尽管有一致的结果支持该模型和方法，但反应模式多种多样，各治疗情景内和情景间个体足够重要差异值的分布范围较广。
根据治疗的具体情况，人们希望总体疾病严重程度平均降低25%至57%，以证明常用感冒治疗方法的成本和风险合理。随机试验证据并不支持如此大的益处。该模型和这些方法应进一步开发，以便用于其他疾病实体。
