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