Clinical significance of health status assessment measures in head and neck cancer: what do quality-of-life scores mean?
OBJECTIVE
To determine the magnitude of clinically significant differences in domain scores for a quality-of-life questionnaire specific to head and neck cancer; and to demonstrate a clinically relevant method of presenting head and neck cancer-specific quality-of-life data using cutoff scores and clinical anchors.


METHODS
Anchor-based and distribution-based techniques for determining clinically significant differences in health-related quality-of-life scores were used.


METHODS
University-based tertiary care hospital.


METHODS
A total of 421 patients with head and neck cancer enrolled in a longitudinal outcomes project.


METHODS
The Head and Neck Cancer Inventory; clinical anchor health status in the domains of speech, eating, and social disruption; and distribution-based clinically significant score differences.


RESULTS
Clinical anchor health states representing incremental levels of dysfunction were significantly correlated with domain scores for eating, speech, and social disruption. The anchor-based clinically important difference magnitudes were consistent with the values obtained using distribution-based techniques. For mean domain scores (minimum, 0; maximum, 100), differences of approximately 4, 10, and 14 or greater represented small, intermediate, and large clinically significant differences, respectively. Stratifying mean domain scores into low (0-30), intermediate (31-69), and high (70-100) categories allowed presentation of the health-related quality-of-life data in a clinically relevant format.


CONCLUSIONS
This study provides benchmarks for small, intermediate, and large clinically significant changes in scores and demonstrates the presentation of health-related quality-of-life data in a clinically useful format.
Funk
Gerry F
GF
Department of Otolaryngology-Head and Neck Surgery, University of Iowa College of Medicine, Iowa City, USA.
Karnell
Lucy H
LH
Smith
Russell B
RB
Christensen
Alan J
AJ
D019985:Benchmarking / Q000379:methods*; D006258:Head and Neck Neoplasms / Q000628:therapy*; D006304:Health Status; D006801:Humans; D007484:Iowa; D008137:Longitudinal Studies; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011788:Quality of Life; D012015:Reference Standards; D016008:Statistical Distributions