Effectiveness of Lessons Attended in a Voluntarily Shortened Strengthening Families Program

The Strengthening Families Program has a sizable implementation cost, which raises the need to evaluate its efficiency with a lower dosage or fewer sessions. Notably, this Program allows parents and children to attend fewer lessons than those offered voluntarily. The efficiency, largely uncharted, is the focus of the present study to examine the effectiveness of a Voluntarily Shortened Strengthening Families Program and its dosage, as embedded in a social work service. The study engaged 182 families in the Chinese metropolis of Hong Kong, including 91 families attending and 91 families not attending the Program (or training and comparison groups), respectively. Results supported the effectiveness of the Voluntarily Shortened Program and its dosage in terms of the number of lessons attended by the parent and her or his child in raising the parent's parenting competence and reducing the child's psychosocial risk reported by the parent and child. However, the effect on parenting competence diminished with higher dosages. This finding implies the parent's satiation with the dosage after attending some lessons, and thus benefit from an optimal dosage (i.e., 11 parent and child lessons) of the Program. By contrast, children preferably attend more lessons in the Program to alleviate their psychosocial risk. © The Author(s) 2026.