Reliability and validity of COOP/WONCA functional health status charts for stroke patients in primary care

Abstract

Dartmouth Coop Functional Health Assessment/World Organization of National Colleges, Academies and Academic Association of General Practitioners (COOP/WONCA) functional health assessment charts depict levels of function/well being along 5-point ordinal scales in 6 domains. Responses, illustrated by drawings, make these charts a suitable tool for the stroke population, given the high prevalence (20%) of language impairment in this population. This study examined the validity and reliability of COOP/WONCA charts for community-dwelling stroke survivors. A total of 55 participants in this cross-sectional study completed COOP/WONCA Charts, Hospital Anxiety and Depression Scale (HAD), Stroke Specific Quality of Life Scale (SSQoL), EuroQoL EQ-5D and visual analogue scale (VAS), International Physical Activity Questionnaire (IPAQ), and Astrand-Rhyming submaximal oxygen volume (VO₂) fitness test. Spearman's correlation coefficient was used to test criterion validity, Cronbach's α was used to test internal validity, and the Mann-Whitney U tested discriminative validity. A subgroup (n = 30) completed COOP/WONCA charts 2 days later, and test-retest reliability (Kendall's τ-b statistic) analysis was conducted. Good agreement was observed between COOP/WONCA physical fitness chart, VO₂, and IPAQ (ρ = -0.438, P = .001; ρ = -0.497, P < .001), COOP/WONCA feelings chart and HAD anxiety and depression scores (ρ = 0.498, P < .001; ρ = 0.494, P < .001), COOP/WONCA overall health chart and EuroQol EQ-5D VAS (ρ = -0.535; P < .001), and COOP/WONCA daily activity and social activity charts and SSQoL (ρ = -0.371, P = .005; ρ = -0.463, P < .001). Cronbach's α (0.72) reflected good internal consistency among COOP/WONCA scales. Discriminative ability for independent ambulation and clinical depression was demonstrated (U = 103.5, P < .001; U = 156, P = .015). Test-retest reliability in each domain except Changes in Health was significant at P < .05 (Kendall's τ-b, 0.344-0.653). Our data indicate that the COOP/WONCA Functional Health charts demonstrate good validity and overall reliability for use with stroke patients in primary care.