Background

The COVID-19 pandemic has accelerated the transition to telehealth, including the use of home spirometry in cystic fibrosis. Evaluating the accuracy and precision of longitudinal home spirometry is a requisite for telehealth-based research. This secondary analysis of a CF study (eICE) evaluates whether there are cross-sectional or longitudinal differences between home and clinic spirometry.

Methods

Participants age ≥14 years with ppFEV₁>25 were recruited from 2011-2015, issued a home spirometer, and asked to complete spirometry efforts twice per week for one year. Clinic spirometry was collected at baseline and every three months. Cross-sectional differences between clinic spirometry and the closest home spirometry measurement were analyzed. Longitudinally, we apply 5 methods to analyze the precision of home spirometry, and differences between clinic vs. home data.

Results

Home spirometry is estimated to be 2.0 (95% CI: 0.3, 3.5) percentage points lower than clinic spirometry cross-sectionally. Longitudinally, the estimates of 12-month change in home spirometry varied by analysis method from -2.6 to -1.0 ppFEV₁/ year, with precision markedly different. However, home spirometry change estimates were qualitatively similar to the clinic results: -3.0 ppFEV₁/year (95% CI: -4.1, -1.9).

Conclusions

To leverage the potential cost, feasibility and convenience of home spirometry, the differences with clinic spirometry must be acknowledged. Significantly lower ppFEV₁ in home devices shows that direct comparison to clinic spirometers may induce a spurious change from baseline, and additional variability in home devices impacts statistical power. The effect of coaching, setting, and equipment must be understood to use and improve home spirometry in CF.

中文翻译：

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临床和家庭肺活量测定作为囊性纤维化长期结果的比较

背景

COVID-19 大流行加速了向远程医疗的过渡，包括在囊性纤维化中使用家庭肺活量测定法。评估纵向家庭肺量计的准确性和精确度是基于远程医疗的研究的必要条件。这项 CF 研究 (eICE) 的二次分析评估家庭和诊所肺活量测定之间是否存在横断面或纵向差异。

方法

从 2011-2015 年招募年龄≥14 岁且 ppFEV ₁ >25 的参与者，发放家用肺活量计，并要求在一年内每周完成两次肺活量测定。在基线和每三个月收集一次临床肺活量测定。分析了门诊肺活量测定法和最近的家庭肺活量测定法之间的横断面差异。在纵向上，我们应用 5 种方法来分析家庭肺量计的精度，以及诊所与家庭数据之间的差异。

结果

据估计，家庭肺活量测定比门诊肺活量测定横断面分析低 2.0 (95% CI: 0.3, 3.5) 个百分点。从纵向上看，家庭肺活量测定 12 个月变化的估计因分析方法而异，从 -2.6 到 -1.0 ppFEV ₁ / 年，精度明显不同。然而，家庭肺量计变化估计值与临床结果在性质上相似：-3.0 ppFEV ₁ /年（95% CI：-4.1，-1.9）。

结论

为了利用家庭肺量测定的潜在成本、可行性和便利性，必须承认与诊所肺量测定的差异。家用设备中ppFEV ₁的显着降低表明与诊所肺活量计的直接比较可能会导致基线的虚假变化，并且家用设备的额外可变性会影响统计能力。必须了解指导、设置和设备的影响，以在 CF 中使用和改进家庭肺量计。