FACTORS CONTRIBUTING TO THE CEILING EFFECT AMONG PATIENTS WITH PROSTATE CANCER WHO WERE JUDGED TO HAVE “FULL-HEALTH” BY EQ-5D-5L

Author(s)

Murasawa H¹, Matsuoka Y², Tanaka N³, Takeda Y¹, Uchikawa S¹, Noto S⁴, Shimozuma K¹
¹Ritsumeikan University, Kusatsu, Japan, ²Kagawa University, Kagawa, Japan, ³Nara Medical University, Kashihara, Japan, ⁴Niigata University of Health and Welfare, Niigata, Japan

Presentation Documents

PCN202--strong-u-murasawa-h-u-sup-1-sup-strong-matsuoka-y-sup-2-sup-tanaka-n-sup-3-sup-takeda-y-sup-1-sup-uchikawa-s-sup-1-sup-noto-s-sup-4-sup-shimozuma-k-sup-1-sup-br-sup-1-sup-ritsumeikan-university-kusatsu-japan-sup-2-sup-kagawa-univers ...

OBJECTIVES: The first Japanese guidelines for the economic evaluation of drugs and medical devices were officially approved in 2016. These guidelines recommend using utility values, especially those evaluated with EuroQol Five-Dimensional Questionnaire (EQ-5D). Recently, a Japanese version of the EQ-5D five level (5L) value set was developed. However, the ceiling effect that can be judged as full health (utility value = 1) was not fully improved comparing to the previous 3L version. We aimed to identify the factors that contributed to the ceiling effect among patients with prostate cancer by using EQ-5D-5L.

METHODS: A cross-sectional study utilized self-administered EQ-5D-5L as the generic health-related QOL and the Functional Assessment of Cancer Therapy-Prostate Cancer (FACT-P) as the disease-specific instrument. Two hundred Japanese patients with prostate cancer in two hospitals were recruited (100 patients in each). Utility values were calculated, and the correlation of values between EQ-5D-5L and FACT-P was checked using least-square method. The physicians in charge reported the patient characteristics. Step-wise selection and logistic regression analysis were used to identify demographic and medical factors associated with subjective judgment of full health.

RESULTS: Self-administered questionnaires and medical characteristics were obtained from 161 patients. The EQ-5D-5L utility value was positively correlated with FACT-P score (r=0.57, p<0.001). The EQ-5D-5L utility values (standard deviation) for localized, advanced, and castration-resistant prostate cancer (CRPC) were 0.86 (0.16), 0.87 (0.14) and 0.80 (0.18), respectively. Of the patients, 47.8% were judged to be at full health by EQ-5D-5L, although only one patient showed the maximum FACT-P score. Regression analysis suggested that full health was affected by age (β=-0.10, p<0.001) and months since the last treatment (β=0.01, p=0.004).

CONCLUSIONS: The age of patients and months since the last treatment significantly contributed to the ceiling effect of EQ-5D-5L utility values. We obtained the utility values of localized, advanced, and CRPC.

Conference/Value in Health Info

2017-11, ISPOR Europe 2017, Glasgow, Scotland

Value in Health, Vol. 20, No. 9 (October 2017)

Code

PCN202

Topic

Patient-Centered Research

Topic Subcategory

Health State Utilities, Patient-reported Outcomes & Quality of Life Outcomes

Disease

Oncology, Urinary/Kidney Disorders

Presentation