Interpretation and content validity of the items of the Hamilton inventory to evaluate outcomes in Persian-speaking patients with complex regional pain syndrome: A cognitive interview approach

The Hamilton Inventory for complex regional pain syndrome (CRPS) is a multidisciplinary assessment tool to evaluate signs and symptoms in patients with CRPS, developed in the English language. This study aims to translate and cross-culturally adapt this tool for Persian-speaking patients with CRPS. Furthermore, this study aimed to understand how 1) Persian-speaking experts and patients interpret and calibrate responses to items on the Hamilton Inventory and 2) compensatory strategies that might affect responses. A cross sectional study with cognitive interview method. Ten health care providers and 10 patients with CRPS were interviewed using cognitive interviewing techniques (talk-aloud, semi-structured interview probes). All interviews were recorded and transcribed verbatim. A directed content analysis was done to analyze the interviews using a previously established framework. Overall, the items on the Hamilton Inventory were well received by participants. Areas, where questions were unclear to some participants were recorded and categorized into five themes: Clarity and Comprehension (100%) in item 1 from the health professional tool and (65%) from the eleven items of the patient-reported tool. Perspective modifiers of culture influenced the calibrations of items “I feel my condition has negatively affected my relationships.” (12%) and “My symptoms affect my comfort level with intimacy.” (20%) from the patient-reported tool. The findings of this study demonstrate that there is no need for substantive changes to the items of the Hamilton Inventory, as they tend to be understood by Persian-speaking experts and patients with CRPS. •Persian version of HI-CRPS valid for assessing symptoms in Persian patients; can be used in clinical practice.•Psychometric properties of Persian HI-CRPS can be tested in clinical practice with Persian-speaking patients.•Persian experts and patients understand items of Persian HI-CRPS for evaluating Complex Regional Pain Syndrome.