Supplementary Material for: Prognostic Implication of Diagnostic Confidence Level in Patients with Fibrotic Hypersensitivity Pneumonitis

<b><i>Background:</i></b> Hypersensitivity pneumonitis (HP) has various clinical courses and outcomes, but the prognostic factors are not well-defined. Vasakova et al. [Am J Respir Crit Care Med. 2017 Sep;196(6):680–9] have proposed a diagnostic algorithm that categorized suspected patients according to the level of confidence in the diagnosis. This study aimed to investigate whether the confidence level of clinical diagnosis has prognostic implication in patients with fibrotic HP. <b><i>Methods:</i></b> This study included 101 biopsy-proven fibrotic HP patients diagnosed between 2002 and 2017. The patients were retrospectively classified into confident, probable, possible, and unlikely chronic HP, according to the confidence level in the diagnostic criteria/algorithm. The survival and forced vital capacity (FVC) changes were compared between the groups. Risk factors for mortality were analysed using a Cox proportional hazard model. <b><i>Results:</i></b> The median follow-up duration was 67.6 months. The mean age was 60.4 years, and percentages of women were 60.4%. When classified based on the diagnostic criteria/algorithm, possible HP was the most common (51.5%), followed by probable (26.7%), confident (9.9%), and unlikely HP (6.9%). Distinctive survival curves were found according to the diagnostic confidence level, showing the worst outcome in unlikely chronic HP (median survival, 30.2 months). In a multivariable Cox analysis, unlikely HP was a significant predictor of poor survival (hazard ratio, 4.652; 95% confidence interval, 1.231–17.586; <i>p</i> = 0.023), after adjustment for age, body mass index, FVC, and diffusing capacity. <b><i>Conclusions:</i></b> The diagnostic confidence level may predict clinical outcomes in patients with HP. Unlikely HP was shown to have a significantly poorer survival than other diagnostic confidence levels.

<b><i>研究背景：</i></b> 过敏性肺炎（Hypersensitivity pneumonitis, HP）存在多样的临床病程与转归，但目前其预后因素尚未明确阐明。Vasakova等[《美国呼吸与重症监护医学杂志》, 2017年9月;196(6):680–9]提出了一套诊断算法，可依据诊断置信度水平对疑似患者进行分类。本研究旨在探讨临床诊断置信度水平是否对纤维化HP患者具有预后意义。
<b><i>研究方法：</i></b> 本研究纳入了2002年至2017年间确诊的101例经活检证实的纤维化HP患者。研究人员依据诊断标准/算法的置信度水平，对患者开展回顾性分类，分为置信、很可能、可能以及可疑度极低的慢性HP四个层级。随后比较各组间的生存情况与用力肺活量（forced vital capacity, FVC）变化，并采用Cox比例风险模型（Cox proportional hazard model）分析死亡相关危险因素。
<b><i>研究结果：</i></b> 本研究的中位随访时长为67.6个月，患者平均年龄为60.4岁，女性占比60.4%。按诊断标准/算法分类后，可能HP最为常见（51.5%），其次为很可能HP（26.7%）、置信HP（9.9%）以及可疑度极低HP（6.9%）。不同诊断置信度水平对应的生存曲线存在显著差异，其中可疑度极低的慢性HP患者预后最差（中位生存期30.2个月）。多变量Cox分析结果显示，在校正年龄、体质量指数、FVC以及弥散功能后，可疑度极低HP是不良生存的显著预测因子（风险比4.652；95%置信区间1.231–17.586；<i>p</i>=0.023）。
<b><i>研究结论：</i></b> 诊断置信度水平可有效预测HP患者的临床转归。与其他诊断置信度分级相比，可疑度极低HP患者的生存期显著更短。