Evaluating the content validity of the Single Assessment Numeric Evaluation (SANE) in shoulder pathologies

BACKGROUND: The Single Assessment Numeric Evaluation (SANE) is a single item patient reported outcome measure (PROM) of function, in where patients rate how normal they feel in relation to a specific joint or problem. Although validated for some orthopedic conditions, it is not yet validated for a population with shoulder pathologies; nor have other studies explored the content validity. This study aims to understand how 1) patients with shoulder conditions interpret and calibrate responses to the SANE and 2) how they define normal. METHODS: This study uses cognitive interviewing, a qualitative methodology that focuses on the interpretation of questionnaire items. Patients with rotator cuff disorders (n = 10), clinicians (n = 6) and measurement researchers (n = 10) were interviewed using a talk aloud structured interview that evaluated the SANE. All interviews were recorded and transcribed verbatim by one researcher (R.F). Analysis was done through an open coding scheme using a previously established framework for classification of interpretation variances. RESULTS: Overall, the single-item SANE was well received by all participants. Through the interviews, the themes of: Comprehension (20% of participants), Reference Point (20% of participants), Relevance (10% of participants), and Perspective Modifiers (50% of participants) emerged as potential sources of interpretation variances. Clinicians indicated this tool facilitates discussion when trying to create realistic recovery expectations for patients post-operatively. The word "normal" was defined by the themes of: 1) levels of current pain compared to pre-injury, 2) personal expectations of recovery and 3) pre-injury activity levels. CONCLUSIONS: Overall, respondents found the SANE to be cognitively simple, but it was clear that the interpretation of the question and what factors calibrated their responses were highly variable between respondents. The SANE is perceived favorable by patients and clinicians, while providing a low response burden. However, the construct being measured may vary between patients.