Construct Validity and Test-Retest Reliability of the Climbing Stairs Questionnaire in Lower-Limb Amputees

Abstract

de Laat FA, Rommers GM, Geertzen JH, Roorda LD. Construct validity and test-retest reliability of the Climbing Stairs Questionnaire in lower-limb amputees. Objective To investigate the construct validity and test-retest reliability of the Climbing Stairs Questionnaire, a patient-reported measure of activity limitations in climbing stairs, in lower-limb amputees. Design A cross-sectional study. Setting Outpatient department of a rehabilitation center. Participants Lower-limb amputees (N=172; mean ± SD age, 65±12y; 71% men; 82% vascular cause) participated in the study; 33 participated in the reliability study. Interventions Not applicable. Main Outcome Measure(s) Construct validity was investigated by testing 10 hypotheses: limitations in climbing stairs according to the Climbing Stairs Questionnaire will be greater in lower-limb amputees who: (1) are older, (2) have a vascular cause of amputation, (3) have a bilateral amputation, (4) have a higher level of amputation, (5) have more comorbid conditions, (6) had their rehabilitation treatment in a nursing home, and (7) climb fewer flights of stairs. Furthermore, limitations in climbing stairs will be related positively to activity limitations according to: (8) the Locomotor Capabilities Index, (9) the Questionnaire Rising and Sitting down, and (10) the Walking Questionnaire. Construct validity was quantified by using the Mann-Whitney U test, Kruskal-Wallis test, and Spearman correlation coefficient. Test-retest reliability was assessed with a 3-week interval and quantified using the intraclass correlation coefficient (ICC). Results Construct validity (8 of 10 null hypotheses not rejected) and test-retest reliability were good (ICC=.79; 95% confidence interval, .57–.90). Conclusion The Climbing Stairs Questionnaire has good construct validity and test-retest reliability in lower-limb amputees.