Portuguese Version of the MISSCARE Survey-Patient: A Cross-Cultural Validation Study

Background: Missed Nursing Care is a comprehensive, multidimensional, and frequently occurring phenomenon in various clinical contexts in Portugal. Objective: This study aimed to translate, adapt, and cross-culturally validate the MISSCARE Survey-Patient for the Portuguese population and to analyze the quality of its measurement properties. Methods: An exploratory–descriptive, quantitative, cross-sectional validation study was conducted. The questionnaire underwent cross-cultural adaptation through translation, translation synthesis, and back-translation procedures, followed by harmonization by an expert committee, pre-testing, and field testing. Results: Ten hospitalized persons and ten nurses participated in the pre-test as experts, while 135 hospitalized persons were included in the field testing. In the pre-testing, excellent content validity indices were obtained for clarity (S-CVUI/Med of 0.98 and S-CVI/UA of 0.84) and cultural relevance (S-CVUI/Med and S-CVI/UA of 1.00) for the overall instrument. In the field testing, a final three-dimensional model (Basic Care, Communication, and Time to Response) was obtained, explaining 66.7% of the total variance. Evidence based on internal structure was supported by Structural Validity indices from the confirmatory factor analysis [X2(56) = 52.421, p < 0.001, χ2/df = 2.722; PCFI = 0.640 and CFI = 0.892]. Convergent Validity was demonstrated through a moderate correlation between the instrument and a question assessing satisfaction with care (r = −0.677; p < 0.001). For the overall instrument, Cronbach’s α was 0.818, indicating very good Internal Consistency, while values for the dimensions ranged between 0.766 and 0.902. Minimal Important Change exceeded the Smallest Detectable Change by seven points for the total instrument, suggesting good potential to detect meaningful changes. Conclusions: The MISSCARE Survey-Patient-PT demonstrates good measurement properties for assessing hospitalized patients’ perceptions of the occurrence of Missed Nursing Care in Portuguese health services.