Measuring Patients' Knowledge about Heart Failure

Patient education is a cornerstone in the management of chronic heart failure and health care professionals spend a lot of time educating patients. It is therefore of great importance to evaluate the effects of the given education. One outcome of importance to measure is knowledge. However, so far validated instruments measuring knowledge are scarce. Less than a handful has previously been reported in the literature and their process of testing has not been well described 1. It was therefore with great interest that I read the papers by Lainscak and Keber 2 and van der Wal et al. 3 in this issue of the journal presenting the development and testing of two instruments measuring knowledge about heart failure. Before specifically commenting on the two instruments, there are three fundamental questions that need to be addressed: How can knowledge be defined? What knowledge on heart failure is most important? How should knowledge be measured? Knowledge refers to what one knows and understands. Knowledge can be categorised as either explicit or implicit. Knowledge that is understood, but unstructured and not easily expressed and shared with others is called implicit knowledge. Knowledge that is organised and structured and easy to recall and share with others is called explicit knowledge. To convert implicit knowledge into explicit knowledge, it must be extracted and formatted. Many patients with heart failure only have implicit knowledge regarding their condition and cannot e.g. give a rational for symptom management or define heart failure or describe the effects of their medication 1. Knowledge represents the lowest level of learning outcomes in the cognitive domain in Bloom's taxonomy 4 that consists of six levels shown in Fig. 1. The first level Knowledge is defined as the ability to remember previously learned material and to recall facts or whole theories. The second level is Comprehension, which means grasping the meaning of a material and the ability to interpret, explain or summarise as well as predicting outcomes and effects. The next level is Application meaning the ability to use learned material in new situations and apply rules, methods and theories. The fourth level is Analysis, breaking down into parts, understanding and concluding. Level five is Synthesis, the ability to put parts together to form a new whole. The last level Evaluation includes the ability to judge processes and effects and support judgment with reasons 4. According to the model of self-management by Riegel et al. 5, patients with heart failure need cognitive skills on the higher levels of Bloom's taxonomy in order to be able to monitor and judge symptoms, perform and evaluate symptom management. For example a patient should be able to monitor their daily weight, judge when a weight gain is caused by fluid retention and there is a need to e.g. take extra diuretics. Further the patients need to be able to continue monitoring the weight and evaluate the effect of their interventions. The six levels of Bloom's taxonomy General knowledge on the condition, as well as knowledge on medications and self-care management is presented as important in national and international guidelines 6,7. These recommendations are written by the health care professional. The preference and perspective of the patients are not included. One study comparing patients' and nurses' perceptions on the importance of various educational topics have shown that there are similarities, but also diversities between these two groups 8. Guidelines can give an overview of educational topics, but the individual needs and skills vary widely between individuals with heart failure. The Dutch Heart Failure Knowledge Scale developed by van der Wal et al. 3 is a 15-item, multiple-choice instrument derived from earlier tools measuring heart failure knowledge in general and about treatment and symptoms. The focus is on non-pharmacological self-care behaviour and only one general question addresses medical treatment. The Patient Knowledge Questionnaire developed by Lainscak and Keber 2 is a 10-item instrument with eight yes/no questions, one multiple-choice and one open-ended question. This questionnaire is in my opinion not a pure knowledge instrument. It is a mixture of evaluating if education has been given, patient satisfaction and self-care behaviour. Only a few items evaluate knowledge. Content, face and construct validity as well as reliability by inter-item correlation and internal consistency was established for both questionnaires 2,3. Both knowledge scales 2,3 have few items. This is good from a patient's perspective. Old, fragile heart failure patients do not have the energy to complete long questionnaires. On the other hand from the researchers' point of view, it might not be enough items in order to fully explore the knowledge of the patients. A limited number of items also make the selection to include relevant areas more difficult. I find the items in both scales quite relevant, but I miss questions about medications and the level of evidence for some self-care advises is low 6. The questionnaire by van der Wal et al. 3 is called the Dutch questionnaire raising the question if knowledge questionnaires should be developed nationally and harmonise with national guidelines or if a European or worldwide knowledge instrument can be developed and used to measure knowledge in heart failure. The approach taken by Lainscak and Keber 2 and van der Wal et al. 3 is to measure knowledge by questions with multiple-choice or categorical (yes/no) answers and presenting the results as a total score. The information we get from these types of questionnaires is descriptive, but incomplete in terms of assessing comprehension and application of knowledge. Depending on the type of educational intervention, these measures of knowledge might not be sensitive enough to evaluate the educational effects. The evaluation of knowledge is difficult and complex. Multiple-choice questionnaires can be used as a way of quantifying knowledge, but it does not give a deeper understanding of the level or if the knowledge is fragmented or deepened, implicit or explicit and if the patients have the ability to analyse and draw conclusions and use their knowledge in new situations. Further research is needed, both the continuous work with developing and revising instruments such as the two presented in this journal 2,3 and finding new, more in-depth methods for evaluating different levels of knowledge and cognitive skills in patients with heart failure. Questionnaires will identify selective knowledge and behaviour, but not the reasoning capacity of the patients. We need instruments that can evaluate how the patients' knowledge was organised before the education and how new information was integrated into prior knowledge. We need to gain insight in the mechanism of how knowledge is processed, memorised and learnt.