Objective: To analyze the content of the nursing diagnosis deficient knowledge in individuals with heart failure. Methods: Methodological study to validate the content of a nursing diagnosis based on the predictive model of diversity, carried out through the organization of the phenomenon of interest and analysis by judges using the collective wisdom model. The NANDA-I Knowledge Deficient diagnosis was evaluated by 48 judges and considered valid when it presented a median content validity index ≥ 0.8 in the confidence intervals.Results: Note that 66.6% of the judges indicated that the new definition proposed was more adequate than the definition adopted by NANDA-I. After the experts' analysis, the following defining characteristics were considered valid: inaccurate statements about the disease and/or therapy, inadequate performance in the management of intercurrences, increase in hospital readmissions, worsened quality of life, deficit in self-care performance, and follow-up of inadequate instruction; related factors are as follows: inadequate guidance offered by health professionals, nonparticipation of the patient in the planning of their health care, weakened relationship between professional and individual; populations at risk-elderly and low level of education of the individual and/or caregiver and the associated condition, mild cognitive impairment. Anxiety, depression, and impaired social interaction were elements considered not relevant to the content domain.
Conclusion: The validation of the content of the aforementioned diagnosis in patients with heart failure, through the analysis of judges with different degrees of expertise, made it possible to improve the definition and expansion of new diagnostic indicators. Implications for nursing practice: Updated diagnostic elements for the nursing diagnosis deficient knowledge in individuals with heart failure will facilitate accurate clinical judgment and the establishment of a therapeutic plan aimed at etiological factors modifiable by nurses.