Oppelaar Martinus C, van Helvoort Hanneke Ac, Bannier Michiel Age, Reijers Monique He, van der Vaart Hester, van der Meer Renske, Altenburg Josje, Conemans Lennart, Rottier Bart L, Nuijsink Marianne, van den Wijngaart Lara S, Merkus Peter Jfm, Roukema Jolt
Department of Pediatric Pulmonology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, Netherlands.
Department of Pulmonary Diseases, Radboud University Medical Center, Nijmegen, Netherlands.
J Med Internet Res. 2024 Dec 3;26:e60892. doi: 10.2196/60892.
Portable spirometers are increasingly used to measure lung function at home, but doubts about the accuracy of these devices persist. These doubts stand in the way of the digital transition of chronic respiratory disease care, hence there is a need to address the accuracy of home spirometry in routine care across multiple settings and ages.
This study aimed to assess the accuracy, reproducibility, and responsiveness to the treatment of home spirometry in long-term pediatric and adult cystic fibrosis care.
This retrospective observational study was carried out in 5 Dutch cystic fibrosis centers. Home spirometry outcomes (forced expiratory volume in one second [FEV], and forced vital capacity [FVC]) for 601 anonymized users were collected during 3 years. For 81 users, data on clinic spirometry and elexacaftor/tezacaftor/ivacaftor (ETI) use were available. Accuracy was assessed using Bland-Altman plots for paired clinic-home measurements on the same day and within 7 days of each other (nearest neighbor). Intratest reproducibility was assessed using the American Thoracic Society/European Respiratory Society repeatability criteria, the coefficient of variation, and spirometry quality grades. Responsiveness was measured by the percentage change in home spirometry outcomes after the start of ETI.
Bland-Altman analysis was performed for 86 same-day clinic-home spirometry pairs and for 263 nearest neighbor clinic-home spirometry pairs (n=81). For both sets and for both FEV and FVC, no heteroscedasticity was present and hence the mean bias was expressed as an absolute value. Overall, home spirometry was significantly lower than clinic spirometry (mean ΔFEV 0.13 L, 95% CI 0.10 to 0.19; mean ΔFVC 0.20 L, 95% CI 0.14 to 0.25) and remained lower than clinic spirometry independent of age and experience. One-way ANOVA with post hoc comparisons showed significantly lower differences in clinic-home spirometry in adults than in children (Δmean 0.11, 95% CI -0.20 to -0.01) and teenagers (Δmean 0.14, 95% CI -0.25 to -0.02). For reproducibility analyses, 2669 unique measurement days of 311 individuals were included. Overall, 87.3% (2331/2669) of FEV measurements and 74.3% (1985/2669) of FVC measurements met reproducibility criteria. Kruskal-Wallis with pairwise comparison demonstrated that for both FVC and FEV, coefficient of variation was significantly lower in adults than in children and teenagers. A total of 5104 unique home measurements were graded. Grade E was given to 2435 tests as only one home measurement was performed. Of the remaining 2669 tests, 43.8% (1168/2669) and 43.6% (1163/2669) received grade A and B, respectively. The median percentage change in FEV from baseline after initiation of ETI was 19.2% after 7-14 days and remained stable thereafter (n=33).
Home spirometry is feasible but not equal to clinic spirometry. Home spirometry can confirm whether lung functions remain stable, but the context of measurement and personal trends are more relevant than absolute outcomes.
便携式肺活量计越来越多地用于在家中测量肺功能，但对这些设备准确性的怀疑依然存在。这些怀疑阻碍了慢性呼吸道疾病护理的数字化转型，因此有必要在多种环境和年龄段的常规护理中解决家庭肺活量测定的准确性问题。
本研究旨在评估长期儿科和成人囊性纤维化护理中家庭肺活量测定的准确性、可重复性和对治疗的反应性。
这项回顾性观察研究在5个荷兰囊性纤维化中心进行。在3年期间收集了601名匿名用户的家庭肺活量测定结果（一秒用力呼气量[FEV]和用力肺活量[FVC]）。对于81名用户，可获得临床肺活量测定和使用依列卡福/替扎卡福/依伐卡福（ETI）的数据。使用Bland-Altman图评估同一天和彼此7天内（最近邻）配对临床-家庭测量的准确性。使用美国胸科学会/欧洲呼吸学会重复性标准、变异系数和肺活量测定质量等级评估测试内的可重复性。通过ETI开始后家庭肺活量测定结果的百分比变化来衡量反应性。
对86对同日临床-家庭肺活量测定和263对最近邻临床-家庭肺活量测定（n = 81）进行了Bland-Altman分析。对于这两组以及FEV和FVC，均不存在异方差性，因此平均偏差以绝对值表示。总体而言，家庭肺活量测定明显低于临床肺活量测定（平均ΔFEV 0.13 L，95% CI 0.10至0.19；平均ΔFVC 0.20 L，95% CI 0.14至0.25），并且与年龄和经验无关，始终低于临床肺活量测定。进行事后比较的单因素方差分析显示，成人临床-家庭肺活量测定的差异明显低于儿童（Δ平均值0.11，95% CI -0.20至-0.01）和青少年（Δ平均值0.14，95% CI -0.25至-0.02）。对于可重复性分析，纳入了311名个体的2669个独特测量日。总体而言，87.3%（2331/2669）的FEV测量和74.3%（1985/2669）的FVC测量符合可重复性标准。进行成对比较的Kruskal-Wallis检验表明，对于FVC和FEV，成人的变异系数均明显低于儿童和青少年。共对5104次独特的家庭测量进行了分级。由于仅进行了一次家庭测量，2435次测试被评为E级。在其余2669次测试中，分别有43.8%（1168/2669）和43.6%（1163/2669）获得A级和B级。ETI开始后7至14天，FEV相对于基线的中位百分比变化为19.2%，此后保持稳定（n = 33）。
家庭肺活量测定是可行的，但不等于临床肺活量测定。家庭肺活量测定可以确认肺功能是否保持稳定，但测量背景和个人趋势比绝对结果更重要。
