Linguistic validation of the Spanish version of the National Cancer Institute's Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE).

PURPOSE: The U.S. NCI's PRO-CTCAE is a library of self-report items for assessing symptomatic adverse events in cancer clinical trials from the patient perspective. The aim of this study was to translate and linguistically validate a Spanish version.
METHODS: PRO-CTCAE's 124 items were translated from English into Spanish using multiple forward and back translations. Native Spanish speakers undergoing cancer treatment were enrolled at six cancer treatment sites. Participants each completed approximately 50 items and were then interviewed using cognitive probes. The interviews were analyzed at the item level by linguistic themes, and responses were examined for evidence of equivalence to English. Items for which ≥20 % of participants experienced difficulties were reviewed, and phrasing was revised and then retested in subsequent interviews. Items where <20 % of respondents experienced difficulties were also reviewed and were considered for rephrasing and retesting.
RESULTS: One hundred nine participants from diverse Spanish-speaking countries were enrolled (77 in Round 1 and 32 in Round 2). A majority of items were well comprehended in Round 1. Two items presented difficulties in ≥20 % of participants and were revised/retested without further difficulties. Two items presented difficulties in <20 %, and when retested exhibited no further difficulties. Two items presented difficulties in <20 %, but were not revised due to lack of alternatives. Sixteen items presented difficulties in ≤12 % and were not revised because difficulties were minor.
CONCLUSIONS: The Spanish PRO-CTCAE has been developed and refined for use in Spanish-speaking populations, with high levels of comprehension and equivalence to the English PRO-CTCAE. TRIAL REGISTRATION: ClinicalTrials.gov:NCT01436240.