ESM for: How happy is happy enough? A cross-cultural comparison of optimal cut points for the Positive Mental Health Scale

As positive mental health (PMH) has a significant impact on general and mental health, it is an important target for interventions. Cut points are a useful basis for identifying participants with a greater need for such interventions. Representative (n = 9,440) and student (n = 22,833) samples from Germany, Russia, the US, and China were reanalyzed. Two different anchors were used to determine optimal cut points for the PMH-scale: (1) a combined measure of PMH-related questionnaires and (2) the Global Assessment of Functioning Scale (GAF). A kernel-based method to determine optimal cut points and bootstrapping to identify potential cross-cultural differences were used. Acceptable to excellent levels of classification accuracy were found regarding the combined measure (AUCs between .75 and .87) across all samples. Using the GAF resulted in poor discriminatory power (AUC = .69). Optimal cut points varied systematically between countries and samples. Country and sample-specific cut points for the PMH scale should be used to identify individuals with high versus low levels of PMH. Specifically, we suggest using cut points of 21, 22, and 24 in Germany, Russia, and the US, respectively. For student samples, we recommend cut points of 18, 19, and 20 in Germany, Russia, and China, respectively.