Abstract
Background: Youth experiencing mental illness and substance use challenges can encounter barriers in accessing services and face high levels of functional impairments. To serve this group better, understanding and measuring the scope of functional problems youth experience is of utmost importance. To date, we are unaware of any existing measure of function for youth with mental health and/or substance use challenges accessing integrated youth services (IYS).
Objective: The objective of this study was to develop a youth-centred measure to capture “function” of young people age 12-24 years accessing IYS for mental health and substance use challenges.
Methods: This study had 4 phases. In phase 1, we conducted 4 focus groups with young people to conceptualize the concept of function (n=44 youth). In phase 2, we used the results to co-design a set of items to capture the construct (n=89 items). In phase 3, we used cognitive debriefing methods and tested the items with a sample of 78 youth using to measure the extent to which these items are fit for purpose to measure function in a clinical and non-clinical sample of young Canadians accessing integrated health services. In this phase, the measure was also called the F-PROM (Function- Person Reported Outcome Measure). In phase 4, we administered the revised items (n=44) to 438 nonclinical youth and 850 clinical youth aged 14-24 years. We used classical test theory and Rasch measurement methods to determine a final item set.
Results: Psychometric analysis from participants provided evidence of strong validity and reliability of the F-FROM. We observed strong convergent validity with well-being and quality of life scores (r >0.60, p<0.001). High F-PROM scores were more strongly associated with better health and lower distress. Rasch analysis showed minimal floor and ceiling effects, good convergent and divergent validity, very good fit to the Rasch model (χ2 = 107.1, df = 90, p = .10)], high reliability (rp = 0.96), an ordered response scale structure, and no item bias for gender or age.
Conclusion: By determining the fitness of purpose of this new measure, this study provides evidence for the F-PROM to be used in IYS to guide further assessment of function and inform interventions to support the function of youth. The measure has the potential to make a significant contribution to the quality of services that youth with mental illness and substance use across IYS services in Canada and beyond. Future research is needed to understand the extent to which the F-PROM can be used as a repeat outcome measure to evaluate the impact of IYS over time.