Mapping scores from the Strengths and Difficulties Questionnaire (SDQ) to preference-based utility values

Area of Science:

• Health Economics
• Child and Adolescent Mental Health
• Psychometrics

Background:

• Quality of life (QoL) is crucial in assessing child mental health outcomes.
• Utility values are essential for health economic evaluations.
• Disease-specific measures like the Strengths and Difficulties Questionnaire (SDQ) are widely used but do not directly yield utility values.

Purpose of the Study:

• To develop preliminary ordinary least squares (OLS) regression algorithms.
• To translate scores from the Strengths and Difficulties Questionnaire (SDQ) to utility values.
• To utilize the preference-based Child Health Utility (CHU9D) instrument for this translation.

Main Methods:

• Two hundred caregivers of children in community mental health services were interviewed.
• The SDQ and CHU9D instruments were administered via telephone.
• OLS regression models were constructed with CHU9D utility as the dependent variable and SDQ subscales as predictors.

Main Results:

• Two algorithms were generated, one using five SDQ subscales and another using three.
• While individual-level prediction showed poor fit (RMSE=.124), the algorithms accurately predicted mean group utility values.
• Preliminary validation confirmed the algorithms' utility for group-level estimations.

Conclusions:

• The study successfully generated algorithms for converting SDQ scores to utility values.
• These algorithms provide a valuable tool for researchers conducting health economic evaluations.
• This facilitates the inclusion of child and adolescent mental health data in economic assessments.