Thériault Rémi, Raz Amir
Faculty of Medicine, McGill University, Montréal, QC, Canada.
Institute for Community and Family Psychiatry, Montréal, QC, Canada.
Can J Respir Ther. 2018 Summer;54(2). doi: 10.29390/cjrt-2018-006. Epub 2018 Aug 1.
Bronchial challenge testing (BCT) measures airway hyperresponsiveness; asthma guidelines recommend using BCT when symptoms manifest despite normal spirometry. Improper application of these guidelines commonly results in the misdiagnosis of asthma. Yet, statistics concerning BCT remain largely obscure. The current paper addresses this gap and explores how various health variables may elucidate adherence to asthma guidelines and patterns of BCT across Canadian provinces.
Using the Access to Information Act, medical financial claims for BCT (or equivalent procedures) were requested from each of the Canadian provinces and territories. Based on the available information (from provinces only), correlations between frequency of BCT claims and medical demographics (e.g., prevalence of respirologists, health expenditures) are reported.
Controlling for population or for people with asthma, physicians from Québec claim four times more BCT per year than those in other provinces; physicians from Alberta close to eight-fold fewer. The number of respirologists per capita and BCT per capita correlated moderately, (132) = 0.582, < 0.001, [95% CI 0.421, 0.716]. Excluding "outliers" (i.e., British Columbia, Alberta, and Saskatchewan) greatly strengthened this correlation, (87) = 0.930, < 0.001, [95% CI 0.883, 0.958].
These findings demonstrate that provinces vary in their use of BCT. This result seems to stem, at least in part, from differences in the prevalence of respirologists. Interestingly, geographic region appears to wield a strong influence; in the correlation between number of tests and number of respirologists, physicians from Western provinces (i.e., Alberta, Saskatchewan, and British Columbia) administered fewer tests than their Eastern colleagues. Given the association between inadequate application of BCT and misdiagnosis of asthma, physicians should pay special attention to the Canadian guidelines when considering an asthma diagnosis.
支气管激发试验（BCT）用于测量气道高反应性；哮喘指南建议，在肺活量测定正常但仍有症状时使用BCT。这些指南应用不当常导致哮喘误诊。然而，关于BCT的统计数据大多仍不明确。本文填补了这一空白，并探讨了各种健康变量如何阐明加拿大各省对哮喘指南的遵循情况以及BCT模式。
根据《信息获取法》，向加拿大各省和地区索取了BCT（或等效程序）的医疗费用报销申请。根据现有信息（仅来自各省），报告了BCT报销申请频率与医疗人口统计学数据（如呼吸科医生患病率、医疗支出）之间的相关性。
在控制人口或哮喘患者数量的情况下，魁北克省的医生每年进行的BCT次数是其他省份医生的四倍；艾伯塔省的医生进行的BCT次数则比其他省份医生少近八倍。人均呼吸科医生数量与人均BCT次数呈中度相关，r(132)=0.582，P<0.001，[95%CI 0.421，0.716]。排除“异常值”（即不列颠哥伦比亚省、艾伯塔省和萨斯喀彻温省）后，这种相关性大大增强，r(87)=0.930，P<0.001，[95%CI 0.883，0.958]。
这些发现表明，各省在BCT的使用上存在差异。这一结果似乎至少部分源于呼吸科医生患病率的差异。有趣的是，地理区域似乎有很大影响；在检测次数与呼吸科医生数量的相关性方面，西部省份（即艾伯塔省、萨斯喀彻温省和不列颠哥伦比亚省）的医生进行的检测比东部同行少。鉴于BCT应用不足与哮喘误诊之间的关联，医生在考虑哮喘诊断时应特别关注加拿大的指南。
