Sears M R, Lewis S, Herbison G P, Robson B, Flannery E M, Holdaway M D, Pearce N, Crane J, Silva P A
Asthma Research Group, McMaster University, Hamilton, Ontario, Canada.
Eur Respir J. 1997 Jan;10(1):51-4. doi: 10.1183/09031936.97.10010051.
A potential source of bias in prevalence rates reported for symptoms and diagnoses of asthma in longitudinal studies could arise if repeated questioning of subjects or previous experience of lung function and airway responsiveness tests increased awareness of respiratory symptoms. We wished to determine the extent of any such bias by comparing reported prevalence rates from a longitudinal and cross-sectional study within similar populations. The prevalences of wheezing in the last year, waking with chest tightness, waking with shortness of breath, waking with coughing, having an attack of asthma in the last year, and current use of medications for asthma were determined using identical questions in two populations. Self-completed questionnaire responses of 946 subjects, 21 yrs of age, participating in the seventh respiratory assessment in the longitudinal Dunedin Multidisciplinary Health and Development Research Study were compared with responses provided by 991 subjects, aged 20-22 yrs, completing a postal questionnaire on one occasion only for the New Zealand section of the European Community Respiratory Health Study. The prevalence rates were not significantly different between the two populations, for all of the reported symptoms and for medication use. Differences in responses between genders were similar in each study, with all responses being more common in females. We conclude that repeated questioning regarding respiratory symptoms and repeated lung function and bronchial challenge testing in a longitudinal study of asthma did not bias prevalence rates compared with those obtained in a similar population of the same age studied on only one occasion.
在纵向研究中，若对受试者进行反复询问，或其有肺功能及气道反应性测试的既往经历，从而提高了对呼吸道症状的认知，那么所报告的哮喘症状及诊断患病率可能会出现偏差。我们希望通过比较相似人群中纵向研究和横断面研究报告的患病率，来确定此类偏差的程度。在两个人群中使用相同的问题，确定了去年喘息、因胸闷醒来、因呼吸急促醒来、因咳嗽醒来、去年哮喘发作以及当前哮喘药物使用情况的患病率。将参与达尼丁多学科健康与发展纵向研究第七次呼吸评估的946名21岁受试者自行填写的问卷回答，与仅一次通过邮寄问卷完成的欧洲共同体呼吸健康研究新西兰部分的991名20 - 22岁受试者的回答进行比较。对于所有报告的症状和药物使用情况，两个人群的患病率没有显著差异。每项研究中，不同性别之间的回答差异相似，所有回答在女性中更为常见。我们得出结论，在哮喘纵向研究中，对呼吸道症状进行反复询问以及反复进行肺功能和支气管激发试验，与仅对相同年龄的相似人群进行一次研究所得出的患病率相比，并不会产生偏差。
