Properties of the 15D and the Nottingham Health Profile questionnaires in patients with lower limb atherosclerotic disease.
OBJECTIVE
The aim of this study was to compare the generic health-related quality of life (HRQoL) instruments, the 15D and the Nottingham Health Profile (NHP), in terms of feasibility, cross-sectional construct validity, discriminatory power, and responsiveness to the change in patients with lower limb atherosclerosis disease (LLAD).


METHODS
Patients who were treated conservatively (64 patients), scheduled for endovascular treatment (85 patients), or for elective surgery (31 patients) filled in the NHP and the 15D questionnaires before treatment and 12 months after. The methods of analysis included calculations of the completion rate, the multitrait-multimethod matrix, extreme group comparisons with the t-test, and calculations of "floor" and "ceiling" effects and effect sizes.


RESULTS
Both the 15D and the NHP instruments were feasible because full data were obtained at baseline from 84.1 percent of patients and 82 percent at 12 months with the 15D and, respectively, 75.8 percent and 79 percent with the NHP. The multitrait-multimethod matrix and extreme group comparisons provided a clear convergent and discriminant evidence of the cross-sectional construct validity of the instruments. The convergent validity correlations were quite high, ranging between .40 and .682. The tendency for higher percentages at the "ceiling" and "floor" for the NHP suggests that it has less discriminatory power than the 15D on roughly comparable dimensions. The 15D and the NHP were almost equally responsive to change.


CONCLUSIONS
This study provided evidence that both the 15D and the NHP are appropriate for measuring HRQoL among patients with LLAD.
Koivunen
Kirsi
K
Department of Nursing Science and Health Administration, University of Oulu, Finland. kirsi.koivunen@oulu.fi
Sintonen
Harri
H
Lukkarinen
Hannele
H
D050197:Atherosclerosis / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D016491:Peripheral Vascular Diseases / Q000523:psychology*; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires