Hyland M E, Crocker G R
Department of Psychology, University of Plymouth, UK.
Thorax. 1995 Jul;50(7):724-30. doi: 10.1136/thx.50.7.724.
Quality of life (QOL) is commonly measured in asthma clinical trials by a questionnaire given before and after treatment. A structured asthma QOL daily diary provides more restricted information but on a daily basis. The validity and use of such a QOL diary was examined in a clinical trial in which two asthma treatments were compared.
The effects of low dose inhaled steroid (400 micrograms beclomethasone dipropionate, BDP) combined with the long acting beta 2 agonist salmeterol (100 micrograms) (n = 220) was compared with high dose inhaled steroid (1000 micrograms BDP) (n = 206) in asthmatic outpatients in a double blind, parallel group study. Outcome measures consisted of a combined diary for peak expiratory flow (PEF) rate, symptoms, and problems, and an asthma-specific QOL questionnaire, the Living with Asthma Questionnaire.
The QOL diary correlated with the QOL questionnaire for both cross sectional and longitudinal assessments. Cross sectional correlations with PEF were higher for the QOL questionnaire than the QOL diary, but longitudinal correlations with PEF were higher for the diary than the questionnaire. Treatment with low dose steroid/salmeterol compared with high dose steroid produced better lung function, better QOL as measured by diary, and reduced night time wakenings, but treatment differences were not obtained with the QOL questionnaire nor for daytime symptoms. Diary assessed QOL was a better predictor of low PEF than diary assessed symptoms. Compliance with diary completion was good but there were floor or ceiling effects in the QOL diary records of about 25% of patients.
Structured QOL diaries are valid instruments that appear to be more responsive to longitudinal change in clinical trials than a QOL questionnaire, but QOL questionnaires provide a more sensitive cross sectional measure of disease severity. Floor and ceiling effects are found in some patients' QOL diaries which limit their usefulness. QOL diary problem events occur during the troughs of a peak flow graph, while symptoms are more widely distributed with respect to peak flow.
在哮喘临床试验中，生活质量（QOL）通常通过治疗前后发放的问卷进行测量。结构化的哮喘QOL每日日记提供的信息更为有限，但却是基于每日情况。在一项比较两种哮喘治疗方法的临床试验中，对这种QOL日记的有效性及应用进行了研究。
在一项双盲、平行组研究中，将低剂量吸入性类固醇（400微克二丙酸倍氯米松，BDP）联合长效β2激动剂沙美特罗（100微克）（n = 220）的效果与高剂量吸入性类固醇（1000微克BDP）（n = 206）在哮喘门诊患者中的效果进行了比较。结果指标包括一份综合日记，记录呼气峰值流速（PEF）、症状和问题，以及一份哮喘特异性QOL问卷，即《哮喘生活问卷》。
无论是横断面评估还是纵向评估，QOL日记与QOL问卷均具有相关性。QOL问卷与PEF的横断面相关性高于QOL日记，但日记与PEF的纵向相关性高于问卷。与高剂量类固醇治疗相比，低剂量类固醇/沙美特罗治疗产生了更好的肺功能、日记所测量的更好的QOL，并减少了夜间觉醒，但在QOL问卷方面以及日间症状方面未观察到治疗差异。日记评估的QOL比日记评估的症状更能预测低PEF。日记填写的依从性良好，但约25%患者的QOL日记记录存在地板效应或天花板效应。
结构化的QOL日记是有效的工具，在临床试验中似乎比QOL问卷对纵向变化更敏感，但QOL问卷能提供更敏感的疾病严重程度横断面测量。在一些患者的QOL日记中发现了地板效应和天花板效应，这限制了它们的实用性。QOL日记中的问题事件发生在峰值流速图的低谷期，而症状在峰值流速方面分布更广泛。
