Construction of the Patient-Oriented Prostate Utility Scale (PORPUS) a multiattribute health state classification system for prostate cancer

Krahn, Murray; Ritvo, Paul; Irvine, Jane; Tomlinson, George; Bezjak, Andrea; Trachtenberg, John; Naglie, Gary

« Previous Next »Journal of Clinical Epidemiology
Volume 53, Issue 9 , Pages 920-930, September 2000

Construction of the Patient-Oriented Prostate Utility Scale (PORPUS)

a multiattribute health state classification system for prostate cancer

Murray Krahn
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada,
- Departments of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada,
- Departments of Program in Clinical Epidemiology and Health Care Research, University of Toronto, Toronto, Ontario, Canada,
- Corresponding author. The Toronto General Hospital, ENG-248, Toronto, Ontario M5G 2C4. Tel: 416-340-4155; fax: 416-595-5826.
Paul Ritvo
- Departments of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada,
- Departments of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada,
- Departments of Psychiatry, University of Toronto, Toronto, Ontario, Canada,
- Departments of Surgery, University of Toronto, Toronto, Ontario, Canada,
- Departments of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada,
- Division of Epidemiology, Biostatistics and Behavioral Science and, Cancer Care Ontario, Toronto, Ontario, Canada
- Division of Preventive Oncology, Cancer Care Ontario, Toronto, Ontario, Canada
Jane Irvine
- Departments of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada,
- Departments of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada,
- Departments of Psychiatry, University of Toronto, Toronto, Ontario, Canada,
George Tomlinson
- Departments of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada,
Andrea Bezjak
- Departments of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada,
- Departments of Program in Clinical Epidemiology and Health Care Research, University of Toronto, Toronto, Ontario, Canada,
John Trachtenberg
- Departments of Surgery, University of Toronto, Toronto, Ontario, Canada,
Gary Naglie
- Departments of Medicine, University of Toronto, Toronto, Ontario, Canada,
- Departments of Program in Clinical Epidemiology and Health Care Research, University of Toronto, Toronto, Ontario, Canada,

Received 23 July 1999; received in revised form 15 December 1999; accepted 26 January 2000.

Abstract

Health status indexes, such as the EuroQol, consist of a health state classification system and a set of utility weights. Indexes measure quality of life using a 0–1 utility score. Utilities for outcomes in prostate cancer (PC) are of unique importance, but generic indexes do not represent PC outcomes (e.g., sexual, urinary, bowel dysfunction) well, and may not capture their full impact. As a step toward improved utility measurement, we constructed a classification system for PC. We generated items for each of six health domains and rated their importance using interviews with 10 clinical experts and 80 patients. Key concepts were selected for each domain using item importance weightings, and a set of predetermined criteria. Text was developed to express levels of severity within each domain. Experts and two additional groups of patients (n = 40, n = 96) evaluated textual clarity and endorsed the content validity of the instrument. The final system consists of 10 domains with 4–6 levels each. The content validity of the system was endorsed by patients and experts. In conjunction with a set of utility weights, it may be used to develop a health status index, to improve utility measurement in patients, and to serve as a short psychometric (nonutility) instrument.

Keywords: Prostate neoplasms, Social values, Decision support techniques, Quality of life, Quality adjusted life years