Did the authors describe a theoretical background or model to support their research questions/ aims?

Read the attached article cited below. Then complete the following questions based on the information in the article.
 
Tong Chien W, Thompson DR, Fong Leung S, Bressington D. Quality of life, symptom severity and level of functioning in people with severe mental illness ready for hospital discharge. J Psychiatr Ment Health Nurs. 2022;29:14–24. https://doi.org/10.1111/jpm.12703
 
Address the following in a narrative format:
According to Melnyk and Fineout-Overholt’s (2015) levels of evidence, based on the research design/procedures, what level is the study? (See https://guides.lib.umich.edu/c.php?g=282802&p=1888246)
Did the authors describe a theoretical background or model to support their research questions/ aims?
If yes, name the theory/framework and if no, suggest a theory/framework and provide a rationale for your choice.
Indicate the variables examined in the study & the tool/measure for each variable.
What were statistical tests used to answer the research questions? Justify why the tests were chosen.
Provide a summary of the significant statistical tests. Include the actual values of all statistically significant results.
Provide a summary of the study results.

Instructions:
Support your positions with evidence from scholarly sources. This questions are selected to provoke thought and discussion.
There is a 5-page limit per question (Please do NOT go above 5 pages), excluding references.
Responses must be in APA 7th edition format and contain appropriate citations and a reference list.
An abstract is not required.
APA 7th Edition Only will be accepted