Schünemann Holger J, Griffith Lauren, Stubbing David, Goldstein Roger, Guyatt Gordon H
Department of Medicine, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
Med Decis Making. 2003 Mar-Apr;23(2):140-9. doi: 10.1177/0272989X03251243.
Health economists recommend that when patients provide preference ratings of their own health state using utility and health state preference measures such as the feeling thermometer (FT) and standard gamble (SG), they first rate hypothetical health states (clinical marker states [CMS]). However, there is no evidence to support improvement in measurement properties with the use of CMS. The authors evaluated validity and responsiveness of the SG and FT with and without administration of the CMS.
Respiratory rehabilitation improves health-related quality of life in patients with chronic airflow limitation. The authors randomized 84 patients undergoing pulmonary rehabilitation to administration of the FTand SG with (FT+ or SG+) or without (FT- or SG-) CMS before and after a standard 12-week respiratory rehabilitation program. Patients also completed the Health Utilities Index 3 (HUI3), the Chronic Respiratory Questionnaire (CRQ), and the St. George Respiratory Questionnaire (SGRQ) to evaluate longitudinal validity.
Marker state status did not significantly affect baseline scores on either FT or SG (FT+ 0.54, FT- 0.60, SG+ 0.68, SG- 0.66, on a scale from 0 [dead] to 1.0 [full health]). The improvement after the rehabilitation program was 0.14 (P < 0.001) in the FT+ group and 0.08 (P = 0.02) in the FT- group (difference between FT+ and FT- = 0.06; 95% confidence interval [CI] = -0.03 to 0.15, P = 0.17). The corresponding improvement was 0.12 (P = 0.009) in the SG+ group and 0.07 in the SG- group (P = 0.11) (difference between SG+ and SG- = 0.05; 95% CI= -0.07 to 0.17, P = 0.39). Correlations between change in the FT+ with the CRQ and SGRQ were slightly but not significantly lower than between the change in FT- and these 2 specific instruments. The correlations between change in the SG with the CRQ and the SGRQ were weaker in patients randomized to SG+ (from 0.00 to 0.17) compared to the SG- group (from 0.21 to 0.58). These differences were statistically significant for the CRQ domains of dyspnea and fatigue.
The authors found nonsignificant trends toward superior responsiveness when patients rated hypothetical health states before rating their own health state. Although including hypothetical health states did not significantly influence the validity of the FT, it decreased the longitudinal validity of the SG. This study fails to show convincing advantage for use of marker states. Theoretical arguments in favor of marker states cannot stand alone without empirical support.
健康经济学家建议，当患者使用效用和健康状态偏好测量方法（如感觉温度计[FT]和标准博弈[SG]）对自身健康状态进行偏好评分时，应首先对假设的健康状态（临床标志物状态[CMS]）进行评分。然而，没有证据支持使用CMS能改善测量属性。作者评估了使用和不使用CMS时SG和FT的有效性及反应性。
呼吸康复可改善慢性气流受限患者的健康相关生活质量。作者将84例接受肺部康复治疗的患者随机分为两组，在标准的12周呼吸康复计划前后，一组接受FT和SG并使用CMS（FT+或SG+），另一组不使用CMS（FT-或SG-）。患者还完成了健康效用指数3（HUI3）、慢性呼吸问卷（CRQ）和圣乔治呼吸问卷（SGRQ）以评估纵向有效性。
标志物状态对FT或SG的基线评分均无显著影响（FT+为0.54，FT-为0.60，SG+为0.68，SG-为0.66，评分范围为0[死亡]至1.0[完全健康]）。康复计划后，FT+组的改善为0.14（P<0.001），FT-组为0.08（P = 0.02）（FT+与FT-之间的差异=0.06；95%置信区间[CI]=-0.03至0.15，P = 0.17）。SG+组的相应改善为0.12（P = 0.009），SG-组为0.07（P = 0.11）（SG+与SG-之间的差异=0.05；95%CI=-0.07至0.17，P = 0.39）。FT+的变化与CRQ和SGRQ之间的相关性略低于FT-的变化与这两种特定工具之间的相关性，但差异不显著。与SG-组（从0.21至0.58）相比，随机分配至SG+组的患者中，SG的变化与CRQ和SGRQ之间的相关性较弱（从0.00至0.17）。这些差异在CRQ的呼吸困难和疲劳领域具有统计学意义。
作者发现，当患者在对自身健康状态进行评分之前对假设的健康状态进行评分时，反应性有不显著的提高趋势。虽然纳入假设的健康状态对FT的有效性没有显著影响，但它降低了SG的纵向有效性。本研究未能显示使用标志物状态有令人信服的优势。支持标志物状态的理论观点若无实证支持则不能成立。
