# Development of a YouthFit Index to assess health-related quality of life in Hong Kong children

## TL;DR

This study developed the YouthFit Index, a tool to assess health-related quality of life in Hong Kong children based on lifestyle factors like sleep and physical activity.

## Contribution

The YouthFit Index is a novel, user-friendly tool for evaluating health-related quality of life in children using modifiable lifestyle variables.

## Key findings

- YouthFit Index scores above 5 are linked to a 43% lower risk of poor health-related quality of life.
- Increased sleep and physical activity improve health-related quality of life in children.
- Longer sedentary periods and later bedtimes are associated with worse health outcomes.

## Abstract

To develop a YouthFit Index, a comprehensive and easily interpretable measure of youth health-related quality of life (HRQoL).

A repeated cross-sectional design was employed to develop and validate the YouthFIt index using the Pediatric Quality of Life Inventory (PedsQL). Activity level and sleep data were collected by a wearable device, Actigraph. Questionnaires were used to gather demographic information and PedsQL data. Multiple-factor analysis of mixed data was employed to identify principal components (PCs) of the modifiable lifestyle variables. The YouthFit Index was calculated by summing the weighted PCs. Logistic regression models were used to assess the odds ratios for risks associated with the YouthFIt Index.

A total of 1,867 students were recruited for the study. The findings showed that having YouthFit Index scores greater than 5 was significantly associated with a lower risk of identifying with special health care needs. Compared to the group with YouthFit Index scores below or equal to 5, the group with scores above the cut-off demonstrated a significant 43 % reduction in the risk of PedsQL total score. The results also revealed that increased sleep duration and physical activity are associated with better HRQoL, while longer sedentary periods and later bedtimes are linked to worse HRQoL.

The YouthFit Index is a user-friendly tool for assessing the HRQoL of Hong Kong Chinese children between the ages of 6 and 17. It can help raise awareness about healthy quality of life and promote health and well-being among children in Hong Kong.