Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, The Netherlands.
Centre for Diagnostic Support in Primary Care, Stichting Huisartsen Laboratorium, Etten-Leur, The Netherlands.
NPJ Prim Care Respir Med. 2014 Aug 14;24:14033. doi: 10.1038/npjpcrm.2014.33.
Forced expiratory volume in 1s/forced expiratory volume in 6 s ( FEV1/FEV6) assessment with a microspirometer may be useful in the diagnostic work up of subjects who are suspected of having COPD in primary care.
To determine the diagnostic accuracy of a negative pre-bronchodilator (BD) microspirometry test relative to a full diagnostic spirometry test in subjects in whom general practitioners (GPs) suspect airflow obstruction.
Cross-sectional study in which the order of microspirometry and diagnostic spirometry tests was randomised. Study subjects were (ex-)smokers aged ≥50 years referred for diagnostic spirometry to a primary care diagnostic centre by their GPs. A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC<lower limit of normal (LLN) from diagnostic spirometry.
One hundred and four subjects were analysed (59.6% males, 42.3% current smokers). Negative predictive values from microspirometry for airflow obstruction based on the fixed and LLN cut-off points were 94.4% (95% confidence interval (CI), 86.4-98.5) and 96.3% (95% CI, 88.2-99.3), respectively. In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.
Pre-bronchodilator microspirometry seems to be able to reliably preselect patients for further assessment of airflow obstruction by means of regular diagnostic spirometry. However, use of microspirometry alone would result in overestimation of airflow obstruction and should not replace regular spirometry when diagnosing COPD in primary care.
使用微肺活量计进行 1 秒用力呼气量/用力呼气量 6 秒（FEV1/FEV6）评估可能有助于初级保健中怀疑患有 COPD 的患者的诊断。
确定在全科医生怀疑气流阻塞的情况下，预支气管扩张剂（BD）微肺活量计检测阴性相对于完整诊断肺活量计检测的诊断准确性。
横断面研究，其中微肺活量计和诊断肺活量计检测的顺序是随机的。研究对象为年龄≥50 岁的（前）吸烟者，由全科医生转诊至初级保健诊断中心进行诊断性肺活量计检查。使用 PiKo-6 微肺活量计测量的预 BD FEV1/FEV6 值<0.73 与后 BD FEV1/FVC（用力肺活量）<0.70 和 FEV1/FVC<正常下限（LLN）比较诊断性肺活量计。
共分析了 104 例患者（59.6%男性，42.3%当前吸烟者）。基于固定和 LLN 截止点，微肺活量计对气流阻塞的阴性预测值分别为 94.4%（95%置信区间[CI]，86.4-98.5）和 96.3%（95% CI，88.2-99.3）。总共，18%的阳性微肺活量计结果未被后 BD FEV1/FVC<0.70 证实，而与气流阻塞的 LLN 标准相比，44%的检测结果为假阳性。
预支气管扩张剂微肺活量计似乎能够可靠地选择患者进行进一步的常规诊断性肺活量计评估气流阻塞。然而，单独使用微肺活量计可能会高估气流阻塞，并且在初级保健中诊断 COPD 时不应替代常规肺活量计。
