Development of a disease-specific instrument for the assessment of quality of life in patients with peripheral arterial occlusive disease

Impairment in health-related quality of life in patients with peripheral arterial occlusive disease (PAOD) are well-known to clinicians, but due to the lack of disease specific assessment instruments, have not been systematically investigated. We describe the development and psychometric testing of a 86-items patient-based questionnaire for the assessment of the quality of life in PAOD containing 7 dimensions: functional status, pain, symptoms, mood, disease related anxiety, social life and treatment evaluation. The questionnaire was included along with standard questionnaires in a prospective study with 308 patients suffering from PAOD in Fontaine stages I to IV before and one week into treatment. Psychometric testing pertained to reliability (internal consistency, retest), validity (convergent, discriminant) and sensitivity (treatment-related change over time). In addition patient acceptance of the questionnaire was assessed. Psychometric testing yield exellent results regarding scale structure and reliability of the newly developed questionnaire. Validity was reflected in high correlations with standard generic questionnaires and in discriminating in quality of life between patients according to disease severity. The sensitivity was reflected in improved quality of life ratings in patients with improved treadmill performance. Patients needed 20 minutes for responding and rated the questionnaire to be easily understandable and not exhausting. These results show that the newly developed PAVK-86 questionnaire is a reliable, valid and sensitive instrument for the assessment of quality of life in patients with arterial occlusive disease which can be used in clinical studies, epidemiological research and quality assurance programs.