Tamblyn R M, Menzies R I, Tamblyn R T, Farant J P, Hanley J
National Centres of Excellence Network in Respiratory Health, McGill University, Department of Epidemiology and Biostatistics, Montreal, Quebec, Canada.
J Clin Epidemiol. 1992 Jun;45(6):603-12. doi: 10.1016/0895-4356(92)90132-7.
Methodological problems have limited scientific investigation of the causes of and solutions for sick building syndrome. The feasibility of using an experimental double blind cross-over study to resolve many of these methodological problems was assessed in a pilot study. The experimental intervention was to vary the amount of outdoor air from 10 cubic feet per minute per person (cfmpp) to 20 cfmpp or 50 cfmpp by central manipulation of the building heating, ventilation and air-conditioning (HVAC) system. Over 6 consecutive study weeks, 2 trials of rates were administered in random order. Study subjects and investigators of the study were blinded to intervention sequence. Unblinding, office environment rating and symptom occurrence were measured weekly. Of 305 eligible workers, 254 participated. Problems were encountered in delivering the lowest dose of ventilation due to building leakage. The prevalence of symptoms diminished steadily over the 6 study weeks, time trends which could be controlled by recommended design modifications. Blinding to the intervention was successfully maintained. Weekly non-response did not introduce a response bias but reduced the number of subjects available for analysis by one-third for each trial. We conclude that this design, with certain modifications, is feasible to evaluate many proposed interventions for sick building syndrome.
方法学问题限制了对病态建筑综合征病因及解决方案的科学研究。在一项初步研究中评估了采用实验性双盲交叉研究来解决其中许多方法学问题的可行性。实验干预措施是通过对建筑物供暖、通风和空调（HVAC）系统进行集中控制，将每人每分钟的室外空气量从10立方英尺（cfmpp）调整为20 cfmpp或50 cfmpp。在连续6个研究周内，以随机顺序进行了2次不同换气率的试验。研究对象和研究人员对干预顺序均不知情。每周测量非盲法、办公环境评分和症状出现情况。在305名符合条件的工人中，有254人参与。由于建筑物泄漏，在提供最低通风剂量时遇到了问题。在6个研究周内症状发生率稳步下降，这种时间趋势可通过推荐的设计改进加以控制。成功维持了对干预措施的不知情状态。每周的无应答并未引入应答偏倚，但每次试验可用于分析的受试者数量减少了三分之一。我们得出结论，这种设计经过某些修改后，对于评估许多针对病态建筑综合征提出的干预措施是可行的。
