Interstitial Lung Disease Program, National Jewish Health, Southside Building, Office #G011 1400 Jackson Street, Denver, CO, 80206, USA.
Division of Pulmonary, Critical Care and Sleep Medicine, Sleep & Behavioral Health Sciences Section, National Jewish Health, Denver, CO, USA.
BMC Pulm Med. 2017 Nov 22;17(1):152. doi: 10.1186/s12890-017-0497-0.
Dyspnea is the hallmark symptom of pulmonary fibrosis. Supplemental oxygen (O) is prescribed to many patients with pulmonary fibrosis in hopes of alleviating dyspnea and improving physical functioning. We used response data from the University of California San Diego Shortness of Breath Questionnaire (UCSD) which was administered monthly in the context of a longitudinal, observational study to plot a rich trajectory for dyspnea over time in patients with pulmonary fibrosis. We used other data from that study to identify clinical predictors of being prescribed O and to provide additional information for how UCSD scores could be used for clinical purposes.
We used linear mixed-effects models and multivariate Cox proportional hazards to model change in dyspnea scores over time and to identify significant predictors of time-to-O-prescription among a pool of clinically-meaningful candidate variables. In the longitudinal study, all decisions, including whether or not to prescribe O, were made by subjects' treating physicians, not members of the research team.
One-hundred ninety-four subjects with pulmonary fibrosis completed more than one UCSD or were prescribed O at some point during the follow-up period (N = 43). Twenty-eight of the 43 had analyzable, longitudinal data and contribute data to the longitudinal UCSD analyses. All 43 were included in the time-to-O-prescription analyses. Subjects prescribed O had more severe dyspnea at enrollment (38.4 ± 19.6 vs. 22.6 ± 18.7, p < 0.0001) and a steeper increase in UCSD scores over time (slope = 1.18 ± 0.53 vs. 0.24 ± 0.09 points per month, p = 0.02) than subjects not prescribed O. Controlling for baseline UCSD score and FVC%, subjects with a clinical summary diagnosis of idiopathic pulmonary fibrosis (IPF) were far more likely to be prescribed O than subjects with other forms of pulmonary fibrosis (hazard ratio = 4.85, (2.19, 10.74), p < 0.0001).
Baseline dyspnea and rise in dyspnea over time predict timing of O prescription. Accounting for disease severity, patients with IPF are more likely than patients with other forms of pulmonary fibrosis to be prescribed O. UCSD scores provide clinically useful information; frequent administration could yield timely data on changes in disease status in patients with pulmonary fibrosis.
The longitudinal study is registered on ClinicalTrials.gov ( NCT01961362 ). Registered October 9, 2013.
呼吸困难是肺纤维化的标志性症状。许多肺纤维化患者都被开具了补充氧气（O）的处方，希望能缓解呼吸困难并改善身体机能。我们使用了加利福尼亚大学圣地亚哥分校呼吸困难问卷（UCSD）的应答数据，该问卷在一项纵向观察研究中每月进行一次，以绘制肺纤维化患者呼吸困难随时间变化的丰富轨迹。我们还使用了该研究中的其他数据来确定开具 O 处方的临床预测因素，并提供有关 UCSD 评分如何用于临床目的的更多信息。
我们使用线性混合效应模型和多变量 Cox 比例风险模型来模拟呼吸困难评分随时间的变化，并确定在一组有临床意义的候选变量中，预测 O 处方时间的重要预测因素。在这项纵向研究中，所有决策，包括是否开具 O 处方，都是由患者的主治医生做出的，而不是研究团队的成员。
194 名肺纤维化患者完成了不止一次 UCSD 问卷或在随访期间的某个时间点被开具了 O 处方（N=43）。43 名患者中有 28 名具有可分析的纵向数据，并为纵向 UCSD 分析提供了数据。所有 43 名患者均被纳入 O 处方时间分析。开具 O 处方的患者在入组时呼吸困难更严重（38.4±19.6 与 22.6±18.7，p<0.0001），UCSD 评分随时间的增加幅度更大（斜率=1.18±0.53 与 0.24±0.09 点/月，p=0.02）。与未开具 O 处方的患者相比，具有特发性肺纤维化（IPF）临床综合诊断的患者更有可能被开具 O 处方（危险比=4.85，（2.19，10.74），p<0.0001）。
基线呼吸困难和随时间推移呼吸困难的增加可预测 O 处方的时间。在考虑疾病严重程度的情况下，IPF 患者比其他形式的肺纤维化患者更有可能被开具 O 处方。UCSD 评分提供了有临床意义的信息；频繁管理可以为肺纤维化患者的疾病状况变化提供及时的数据。
纵向研究在 ClinicalTrials.gov 注册（NCT01961362）。于 2013 年 10 月 9 日注册。
