Quality of life analysis in patients with lower limb ischaemia: suggestions for European standardisation.

INTRODUCTION AND OBJECTIVES In this era of evidence-based medicine and limited resources we seem obliged, on clinical and economic grounds, to demonstrate that we improve not only patient survival but also the quality of patients' lives. This study aims to determine the impact of increasing lower limb ischaemia on quality of life (QOL) and which of three commonly used generic QOL instruments is the most valid, reliable, and responsive to change in patients with lower limb ischaemia. PATIENTS AND METHODS Two hundred and thirty-five patients, 144 men and 91 women, median age 68 years (range 41-87 years) were graded according to ISCVS suggested reporting standards, i.e. 16 mild, 116 moderate and 25 severe claudicants; 33 patients had rest pain and 45 tissue loss. Patients completed Short Form 36 (SF36), EuroQol (EQ-5D) and Nottingham Health Profile (NHP) questionnaires at interview. Additional copies of questionnaires were posted to 80 patients prior to attendance. Correlation between the two sets of responses reflects test-retest reliability. Correlation between domains measured by the three instruments reflects convergent and divergent validity. Kruskal Wallis ANOVA detected QOL changes across the whole group. Spearman Rank was used to analyse validity and reliability. Responsiveness was analysed using the Mann-Whitney U-test. RESULTS Increasing lower limb ischaemia confers significant (p < 0.05) deterioration in: SF36 measured: physical functioning, physical role, pain, general health, vitality, social functioning and mental health. EQ-5D measured: mobility, self-care, usual activities, pain and anxiety/depression. NHP measured: energy, pain, emotional reaction, sleep, social isolation and physical mobility. All three instruments are significantly reliable (rs > 0.7). The validity of SF36 and NHP (rs = 0.68-0.78) is superior to EQ-5D (rs = 0.37-0.7). SF36 & NHP are equally responsive to changes in physical activity and pain. SF36 and EQ-5D are most responsive to changes in social activity. SF36 is most responsive to changes in psychological status. CONCLUSIONS QOL deteriorates markedly with increasing lower limb ischaemia. The SF36 would appear to be the most appropriate generic QOL analysis tool for these patients. We recommend its widespread adoption throughout Europe, thus providing a standardised tool for reporting generic QOL.