Validity and reliability of the measurement instrument of the nursing outcome health-related Physical Fitness (2004), proposed and transculturally adapted to the Spanish context.

Background: Presently, physical inactivity is the main public health problem in many countries worldwide. Physical activity promotes the maintenance or improvement of one's physical condition. Physical fitness has been established as the main biological marker of the state of health of an individual, and therefore, there is a clear need to measure health-related physical fitness through the use of a reliable and valid instrument. This study is a continuation of the transcultural adaptation process and a new proposal of the nursing outcome Physical Fitness (2004), found in the 5 Edition of the Nursing Outcomes Classification. The objective of this study was to examine the validity and reliability of the nursing outcome Health-Related Physical Fitness survey, proposed and transculturally adapted to the Spanish context.

Methods: An instrumental study to validate the nursing outcome Physical Fitness (2004), from the 5 Edition of the Nursing Outcome Classification was carried out. It took place between the months of May, 2016 to May, 2017. On the first stage, the instrument proposed Health-Related Physical Fitness survey was administered to 160 adults who used the Health Services of Murcia, Spain by three independent evaluators. After 4 weeks, it was administered again to 33 participants to calculate the intra-rater reliability. Lastly, the SF-12v2 Health Survey was administered to obtain external evidence of validity.

Results: The inter-rater reliability of the nursing outcome proposed obtained high values (between 0.91-0.99) in the evaluations performed by the three evaluators. As for the intra-rater reliability, high values were obtained (0.94-1), except for the item "balance", which was moderate (0.56). Lastly, a positive and statistically significant correlation (p < 0.05) was obtained between the Physical Component Summary, and the dimensions Physical Functioning and General Health from the SF-12v2 Health Survey, and the global score of the Health-Related Physical Fitness proposed instrument.

Conclusions: The validity and reliability results of the nursing outcome Health-Related Physical Fitness survey, proposed and transculturally adapted to the Spanish context, were adequate for its use by nurses with adults who use the Health Services of Murcia. However, this instrument must be analyzed with more diverse samples of health services users.