3.1. Applying the Theory in Practice. A widely used criterionin evaluating a theory is applying the theory in practice [18].A theory developed in a manner typical of middle-range theories may be used in nursing education and as a tool
for thinking by nursing staff. The concepts can be utilized in analysing and defining an environment that supports
the well-being of the elderly. The consequences that can be derived from the theory are related to directing research and practical work, producing new ideas and separating the key focus of interest of nursing from that of other fields [31]. The theory of an environment supporting the well-being of elderly people is amiddle-range theory that can be applied to other studies. In such cases, the concepts of the theory guide further studies of different kind. For example, further studies may look at how much the different environments in which the elderly live actually contribute to their well-being. After this, the theory can be used as a guideline in practical nursing work or for giving various recommendations to develop it. The theory was tested with confirmatory factor analysis which showed that the validity and reliability of the theory was relatively good. The statistical values as well as the indices of relevance to the data presented as a result of the analysis are sufficient in all the models tested. Using factor analysis in testing the theory was found to be a successful solution, and the indices obtained in the analysis confirmed the hypothetical models formed by the researcher through qualitative analysis.