The More the Better, Only in the Longer Term: A Cluster Randomized Controlled Trial to Evaluate a Compound Intervention Among Mainland Chinese Immigrants in Hong Kong.

Barriers to adaptation faced by mainland Chinese immigrants to Hong Kong can be reduced by improving two targets of adaptation: information about negotiating their new environment and psychological well-being. We developed and evaluated a Compound intervention to address these two domains simultaneously and compared its effects to two separate interventions exclusively targeting either information about Hong Kong or psychological well-being. This cluster randomized controlled trial assigned 251 immigrants to an information provision arm (IP, n = 84) targeting knowledge and adaptation difficulties, a psychological well-being enhancement arm (WBE, n = 80) targeting resilience and mental health, or a Compound arm (i.e., IP + WBE, n = 87). The Compound arm showed stronger effects from baseline to postintervention on knowledge than the WBE arm. From postintervention to 6-month follow-up, the Compound arm showed better sustained effects on knowledge and adaptation difficulties than the IP arm and on resilience and mental health than the WBE arm. Additionally, participants in the Compound arm with more baseline depressive symptoms showed greater improvements in adaptation difficulties and general mental health than those with fewer symptoms. The study demonstrated the longer-term effectiveness of the Compound intervention and its greater benefits for immigrants with more depressive symptoms.