Background and importance 

Clinical diagnosis of community-acquired pneumonia (CAP) is difficult to establish with certainty. Adherence to antibiotic guidelines independently affects the prognosis of CAP patients.

Objective 

We aimed to determine whether guidelines’ adherence was related to CAP diagnosis level of certainty and could be reinforced accordingly to diagnosis improvement.

Design 

Secondary analysis of a prospective, multicenter study, which evaluated the impact of early thoracic CT scan on diagnosis and therapeutic plan in patients with clinically suspected CAP visiting emergency departments.

Setting and participants 

In total 319 patients with clinically suspected CAP were enrolled in four emergency departments, Paris, France, between Nov 2011 and Jan 2013.

Outcome measures and analysis 

We evaluated guidelines’ adherence before and after CT scan and its relationship with CAP diagnosis level of certainty. Antibiotics were categorized as adherent according to 2010 French guidelines. CAP diagnosis level of certainty was prospectively classified by the emergency physicians based on a Likert scale as excluded, possible, probable or definite before and immediately after the CT scan. These classifications and therapeutic plans were also completed by an independent adjudication committee. Determinants of adherence were assessed using Poisson regression with robust variance.

Main results 

Adherence to guidelines increased from 34.2% before CT scan to 51.3% after CT scan [difference 17.1% (95% CI, 9.5–24.7)], meanwhile CAP diagnosis with high level of certainty (definite and excluded CAP) increased from 46.1 to 79.6% [difference 33.5% (95% CI, 26.5–40.5)]. Diagnosis level of certainty before CT scan was the strongest determinant of adherence in multivariate analysis (RR, 2.63; 95% CI, 1.89–3.67).

Conclusion 

Antibiotic guidelines’ adherence was poor and positively related to CAP diagnosis level of certainty. The results suggest that improvements in CAP diagnosis may increase adherence to antibiotic guidelines. Clinical trial registered with www.clinicaltrials.gov (NCT 01574066).

中文翻译：

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诊断确定性水平对 ED 肺炎患者抗生素指南依从性的影响：干预试验的事后分析

背景和重要性 

社区获得性肺炎 (CAP) 的临床诊断很难确定。遵守抗生素指南独立影响 CAP 患者的预后。

客观的 

我们的目的是确定指南的依从性是否与 CAP 诊断的确定性水平相关，并且是否可以根据诊断的改善而得到加强。

设计 

一项前瞻性、多中心研究的二次分析，该研究评估了早期胸部 CT 扫描对临床疑似 CAP 患者的诊断和治疗计划的影响。

设置和参与者 

2011 年 11 月至 2013 年 1 月期间，共有 319 名临床疑似 CAP 患者被纳入法国巴黎的四个急诊科。

结果测量和分析 

我们评估了 CT 扫描前后指南的依从性及其与 CAP 诊断确定性水平的关系。根据 2010 年法国指南，抗生素被归类为粘附性抗生素。CAP 诊断的确定性水平由急诊医师根据 Likert 量表前瞻性地分为 CT 扫描前后排除、可能、很可能或确定。这些分类和治疗计划也由一个独立的裁决委员会完成。使用具有稳健方差的泊松回归评估依从性的决定因素。

主要结果 

遵守指南的比例从 CT 扫描前的 34.2% 增加到 CT 扫描后的 51.3% [差异 17.1% (95% CI, 9.5–24.7)]，同时具有高确定性的 CAP 诊断（明确和排除的 CAP）从 46.1 增加到 79.6 % [差异 33.5% (95% CI, 26.5–40.5)]。CT 扫描前的诊断确定性水平是多变量分析中依从性的最强决定因素（RR，2.63；95% CI，1.89–3.67）。

结论 

抗生素指南的依从性较差，与 CAP 诊断的确定性水平呈正相关。结果表明，CAP 诊断的改进可能会增加对抗生素指南的依从性。在www.clinicaltrials.gov (NCT 01574066)注册的临床试验。