Orr P H, Scherer K, Macdonald A, Moffatt M E
Department of Community Health Sciences, University of Manitoba, Winnipeg, Canada.
J Fam Pract. 1993 May;36(5):507-12.
Acute bronchitis is a common clinical problem that causes considerable morbidity and presents both diagnostic and treatment dilemmas for the physician. An evaluation of all published randomized controlled trials of antibiotics in the treatment of acute bronchitis was conducted to (1) quantitatively assess methodologic rigor, (2) determine if effectiveness of antimicrobial therapy is known, and (3) analyze strengths and weaknesses of randomized controlled trials in family practice settings.
A scoring system for the evaluation of randomized controlled trials was adapted for this study. Four raters, who were blinded to which journals published the studies and the type of antibiotic used in each study, assessed the six-randomized clinical trials for treatment of bronchitis identified through a literature search. The trials were rated according to criteria that measured internal validity.
Scores for internal validity ranged from 65.5 to 102.5 points with a maximum possible score of 120 points (54.6% to 85.4%). The two trials with the highest scores assessed doxycycline and showed no benefit from use of this antibiotic. Single trials that studied erythromycin and trimethoprim-sulfamethoxazole showed improvement in outcome from use of these drugs; however, of the six trials, these two studies ranked fourth and fifth for internal validity. Low scores resulted from small sample size, possible contamination with other treatment measures, and poor assessment of subjects' compliance with antibiotic regimen.
An evaluation of the current literature does not support antibiotic treatment for acute bronchitis. Further studies of this common illness are indicated. It is hoped that this critical review of randomized control trials will prove useful in the planning of future studies, in placing greater emphasis on methodologic rigor, and in giving greater consideration to the practical constraints of research in the family practice setting.
急性支气管炎是一个常见的临床问题，会导致相当高的发病率，给医生带来诊断和治疗方面的两难困境。我们对所有已发表的关于抗生素治疗急性支气管炎的随机对照试验进行了评估，目的是：（1）定量评估方法学的严谨性；（2）确定抗菌治疗的有效性是否已知；（3）分析家庭医疗环境中随机对照试验的优缺点。
本研究采用了一种用于评估随机对照试验的评分系统。四位评分者对通过文献检索确定的六项治疗支气管炎的随机临床试验进行评估，他们不知道这些研究发表在哪些期刊上，也不知道每项研究中使用的抗生素类型。这些试验根据衡量内部效度的标准进行评分。
内部效度得分在65.5至102.5分之间，最高可能得分为120分（54.6%至85.4%）。得分最高的两项试验评估了强力霉素，结果显示使用这种抗生素并无益处。研究红霉素和甲氧苄啶-磺胺甲恶唑的单项试验表明，使用这些药物可改善治疗结果；然而，在这六项试验中，这两项研究在内部效度方面排名第四和第五。得分较低是由于样本量小、可能受到其他治疗措施的干扰以及对受试者对抗生素治疗方案的依从性评估不佳。
对当前文献的评估不支持使用抗生素治疗急性支气管炎。需要对这种常见疾病进行进一步研究。希望对随机对照试验的这一批判性综述将有助于未来研究的规划，更加重视方法学的严谨性，并更多地考虑家庭医疗环境中研究的实际限制因素。
