 |
 |

Scalpdex
A Quality-of-Life Instrument for Scalp Dermatitis
Suephy C. Chen, MD, MS;
Jensen Yeung, MD;
Mary-Margaret Chren, MD
Arch Dermatol. 2002;138:803-807.
Objective To develop a scalp dermatitisspecific quality-of-life instrument.
Methods Based on the results of directed focus sessions with 8 patients with
scalp psoriasis or seborrheic dermatitis, we conceptualized 3 major constructs
that explain the way scalp dermatoses affect patient quality of life: symptoms,
functioning, and emotions. We constructed a 23-item instrument, Scalpdex,
and tested its reliability, responsiveness, and validity.
Results Fifty-two dermatology patients completed the study. We demonstrated
construct validity by confirming that the factors derived by principal axes
factor analyses with orthogonal rotation correlated to our hypothesized scales
(r = 0.76-0.84) and that differences in symptom,
functioning, and emotion scores differed among the varying levels of self-reported
scalp severity more than would be expected by chance (P<.05 by analysis of variance). The instrument demonstrated reliability
with internal consistency (Cronbach , 0.62-0.80) and reproducibility
(intraclass correlation coefficient, 0.90-0.97). The quality-of-life scores
changed in the expected direction in our test for responsiveness (P .05, by paired t test for functioning
and emotion for those who improved). We ascertained the discriminant capability
of Scalpdex compared with a dermatological generic quality-of-life tool, Skindex,
by demonstrating superior responsiveness (P .005
by paired t test in functioning and emotion) and
improved overall sensitivity in individual items.
Conclusions Scalpdex is, to our knowledge, the first quality-of-life instrument
specifically for patients with scalp dermatitis that is reliable, valid, and
responsive. Clinicians can use the instrument to determine which aspect of
the disease most bothers the patient and to evaluate quality of life as one
variable of responsiveness to the therapeutic intervention.
From the Department of Dermatology and Emory Center for Outcomes Research,
Emory University School of Medicine, and Departments of Health Services Research
and Development Medicine and Division of Dermatology, Atlanta Veterans Administration
Medical Center, Atlanta, Ga (Dr Chen); McMaster University, Hamilton, Ontario
(Dr Yeung); the Departments of Dermatology and Medicine, University of California
at San Francisco (Dr Chren); and the Dermatology Service, San Francisco Veterans
Affairs Medical Center (Dr Chren).
|