1 Oxford Outcomes Ltd, Oxford, UK 2 Department of Public Health, Health Economics Research Centre, University of Oxford, Oxford, UK 3 Global Health Outcomes, GlaxoSmithKline, Greenford, UK 4 Medical Psychology, Leiden University Medical Center, Leiden, the Netherlands 5 Department of Pulmonology, Leiden University Medical Center, Leiden, the Netherlands.
Patient. 2008 Dec 1;1(4):309-16. doi: 10.2165/01312067-200801040-00012.
Previous work has suggested that people with poor health-related quality of life (HR-QOL) as a result of asthma are willing to pay the most for successful therapy. There is also evidence that preferences are an important influence on adherence to therapy. We report a patient preference study using a discrete-choice experiment (DCE) to elicit willingness to pay (WTP) of patients with asthma in Spain, the Netherlands, and the UK.
The DCE survey included different attributes of asthma therapy (days with symptoms, days needing reliever medication, asthma attacks [none, attack that does not require doctor/emergency room {ER} visit, attack that requires doctor/ER visit], risk of adverse effects, number of preventer inhalers, and monthly out-of-pocket costs). Participants indicated which attribute combinations they preferred. The questionnaire survey included the mini Asthma Quality of Life Questionnaire (mAQLQ). The validity of the choice experiment has been supported by two pilot studies conducted in the UK. Preferences and WTP were estimated using a random effects probit model. Symptom days and asthma attack attributes were segmented by mAQLQ score.
Demographic and clinical data were compared between the three country samples (UK, n = 124; Spain, n = 86; the Netherlands, n = 269). All study attributes were independently significant predictors of choice. People were willing to pay €35 per month to avoid a day with symptoms, and €109 per month (year 2005 values) to avoid experiencing asthma attacks that required emergency visits to their doctor or hospital. People with the worst HR-QOL were willing to pay the least to avoid days with symptoms and asthma attacks that required visits to their doctor/ER. This was not an income-related effect.
Patients who reported higher HR-QOL were willing to pay more to avoid days with symptoms and asthma attacks that required visits to their doctor/ER. Hypotheses were explored to explain this effect. It is possible that people with the least impairment of HR-QOL place the greatest value on avoiding the effects of asthma and so are most willing to alter their behavior. People with the worst HR-QOL may be exhibiting a response shift type of effect whereby their internal values are shifted down by the burden of their disease. These findings may help to illuminate why there are differences in asthma treatment adherence.
既往研究提示，因哮喘而生活质量较差的患者对治疗效果的获益最为关注，也愿意为此支付更高的费用。同时，偏好也是影响治疗依从性的重要因素。本研究采用离散选择实验（DCE），旨在评估西班牙、荷兰和英国哮喘患者的偏好及其对治疗效果的支付意愿（WTP）。
DCE 调查问卷包括哮喘治疗的不同属性（症状天数、缓解药物天数、哮喘发作次数[无、无需就医/急诊的发作、需要就医/急诊的发作]、不良反应风险、使用预防吸入器的次数、每月自付费用）。参与者需对其偏好的属性组合进行选择。调查问卷还包括 mini Asthma Quality of Life Questionnaire（mAQLQ）。该选择实验的有效性已通过在英国开展的两项预试验得到验证。采用随机效应概率模型对偏好和 WTP 进行估计。根据 mAQLQ 评分对症状天数和哮喘发作属性进行分段。
比较了来自英国（n=124）、西班牙（n=86）和荷兰（n=269）三个国家样本的人口统计学和临床数据。所有研究属性均为选择的独立显著预测因子。患者愿意每月支付 35 欧元来避免 1 天的症状，愿意每月支付 109 欧元（2005 年的价值）来避免需要就医/急诊的哮喘发作。生活质量最差的患者为避免症状天数和需要就医/急诊的哮喘发作，愿意支付的费用最少。这不是收入相关的影响。
报告 HR-QOL 较高的患者为避免症状天数和需要就医/急诊的哮喘发作，愿意支付更多费用。本研究还对导致这一现象的原因进行了假设分析。可能是 HR-QOL 损害最小的患者对避免哮喘发作的影响赋予了更高的价值，因此最愿意改变其行为。HR-QOL 最差的患者可能表现出一种反应转移效应，即他们的内在价值因疾病负担而降低。这些发现可能有助于阐明为什么在哮喘治疗依从性方面存在差异。
