Assessment of content validity and psychometric properties of VISA-A for Achilles tendinopathy

Abstract

A recent COSMIN review found that the Victorian Institute of Sports Assessment–Achilles tendinopathy questionnaire (VISA-A) has flawed construct validity. The objective of the current study was to assess specifically the process of how VISA-A was constructed and validated, and whether the Danish version of VISA-A is a valid patient-reported outcome measure (PROM) for measuring the perceived impact of Achilles tendinopathy. The original item generation strategy for content validity and the process for confirming the scaling properties (construct validity) were examined. In addition, construct validity was evaluated directly using several psychometric methods (Rasch analysis, confirmatory factor analysis (CFA), and multivariable linear regression) in a cohort of 318 persons with Achilles tendinopathy with symptom duration groups ranging from less than 3 months to more than 1 year of chronicity, and a group of 120 healthy persons. We found that the item generation and item reduction in the original construction of VISA-A was based on literature review and clinician consensus with little or no patient involvement. We determined that 1) VISA-A consists of ambiguous conceptual item themes and thus lacks content validity, 2) there was no thorough investigation of the psychometric properties of the original version of VISA-A, which thus lacks construct validity, and 3) rigorous direct assessment of the psychometric properties of the Danish VISA-A revealed inadequate psychometric properties. In agreement with the COSMIN study, we conclude that when used as a single score, VISA-A is not an adequate scale for measuring self-reported impact of Achilles tendinopathy.

Tendinopathy VISAs have expired—is it time for outcome renewals?

“…Notably, the developers of the VISA-A, VISA-H, and VISA-P [ 2 , 15 , 19 ] suggested that the PROM covers more than one domain (pain, function, and sport activity), while the VISA-G covers disability and activity level [ 5 ]. A PROM assessing more than one domain does not conform with unidimensionality [ 3 ]. The internal structure of the VISA-A and VISA-P was never evaluated in the development studies [ 15 , 19 ], but the VISA-H was found to have a 2-factor structure (pain/function and sporting activity) [ 2 ], and reported evidence also suggested a 2-factor structure for the VISA-G (pain/function and weight bearing activities) [ 5 ].…”

“…The internal structure of the VISA-A and VISA-P was never evaluated in the development studies [ 15 , 19 ], but the VISA-H was found to have a 2-factor structure (pain/function and sporting activity) [ 2 ], and reported evidence also suggested a 2-factor structure for the VISA-G (pain/function and weight bearing activities) [ 5 ]. Recently the Modern Test Theory approach has been developed which includes a collection of statistical models including confirmatory factor analysis, item response theory, and Rasch analysis [ 3 ]. This approach is considered the gold standard for validation of patient reported outcomes and their structural validity—and shows that an inconsistent underlying structure for the VISA-A exists violating the assumption that the VISA questionnaires are unidimensional, and thus their computation as a total and single sum score should be avoided [ 3 ].…”

“…Recently the Modern Test Theory approach has been developed which includes a collection of statistical models including confirmatory factor analysis, item response theory, and Rasch analysis [ 3 ]. This approach is considered the gold standard for validation of patient reported outcomes and their structural validity—and shows that an inconsistent underlying structure for the VISA-A exists violating the assumption that the VISA questionnaires are unidimensional, and thus their computation as a total and single sum score should be avoided [ 3 ]. Furthermore, confirmed differential item functioning for sex and across duration of symptoms for VISA-A [ 3 ], seem to exist, which means that certain patient groups with similar levels of disability have a different probability of giving a certain response to a particular item.…”

“…In essence, shortcomings as those highlighted in recent years concerning the VISA-A [ 3 , 11 ], most likely apply to all VISA questionnaires, as also indicated by our recent systematic reviews in this journal from 2021 [ 8 , 9 ]. Beyond the obvious evidence and the appraisal of measurement bonafides of VISA from these reviews, the questionnaires incorporate complex items with complicated scoring and thematic ambiguity [ 3 ] that needs reconsideration. At face value, the sports/physical activity section in VISA questionnaires is unreasonably heavily weighted in the overall scoring leading to erroneous scoring-based assumptions with regards to disability between active and non-active individuals (Fig.…”

“…in VISA-A, VISA-H, and VISA-P cannot be achieved in people who are not sports active and in VISA-G (Are you currently taking part in regular exercise, physical activity or sport?) in individuals who are not physically active [ 3 ]. Given the former, a non-active person’s symptoms may resolve, yet they might only score 50–60 out of 100 [ 11 ].…”