Kiebert G M, Stiggelbout A M, Leer J W, Kievit J, de Haes H J
Medical Decision Making Unit, State University Leiden, The Netherlands.
Med Decis Making. 1993 Apr-Jun;13(2):133-40. doi: 10.1177/0272989X9301300207.
The authors assessed the test-retest reliabilities of two treatment-preference instruments recently applied to the measurement of the utilities of health states after different treatment modalities for cancer. The first instrument measures the strengths of preferences concerning a choice between a wait-and-see policy, and treatment with radiotherapy after an initial surgical breast-conserving procedure for early breast cancer. The second measures the strengths of preferences concerning a choice between two hypothetical surgical treatment outcomes in cancer of the rectum with different probabilities of expected five-year survival. Both measure the strength of a subject's treatment preference given probabilities of treatment-related costs and benefits. The subjects were radiotherapy technicians (n = 20) and cancer patients (n = 20) who were interviewed in weeks 2 and 4 of radiotherapy. The test-retest reliabilities of both instruments were inconsistent and moderately high, with Spearman's rank correlations ranging from 0.38 to 0.81 and weighted kappas ranging from 0.38 to 0.69. To investigate whether the start of treatment with radiotherapy influenced the utilities that patients assigned to health states, the same procedure was applied in another, comparable, group of patients with cancer (n = 20). For this group, the first assessment was made prior to the start of treatment and the second during the second week of radiation therapy. The scores of this group of patients indeed appeared to be less stable than the scores of the patients assessed in weeks 2 and 4 of radiotherapy. However, the instability of the scores could have been the result of test bias.
作者评估了两种治疗偏好工具的重测信度，这两种工具最近被用于测量癌症不同治疗方式后健康状态的效用。第一种工具测量了对于早期乳腺癌在保乳手术初始治疗后采取观察等待策略与放疗治疗之间选择的偏好强度。第二种工具测量了对于直肠癌两种假设手术治疗结果（预期五年生存率概率不同）之间选择的偏好强度。两者均在给出治疗相关成本和收益概率的情况下测量受试者的治疗偏好强度。受试者为放疗技师（n = 20）和癌症患者（n = 20），他们在放疗的第2周和第4周接受了访谈。两种工具的重测信度不一致且中等偏高，斯皮尔曼等级相关系数范围为0.38至0.81，加权卡帕值范围为0.38至0.69。为了研究放疗开始是否会影响患者赋予健康状态的效用，在另一组类似的癌症患者（n = 20）中应用了相同的程序。对于该组患者，第一次评估在治疗开始前进行，第二次评估在放疗的第二周进行。该组患者的分数确实似乎比在放疗第2周和第4周评估的患者分数更不稳定。然而，分数的不稳定性可能是测试偏差的结果。
