Introducing the AltPAI and EnsPAI as Alternatives to the Personalized Advantage Index
Year: 2026
Type: preprint
Abstract: Background: The Personalized Advantage Index (PAI) has evolved into a standard framework to identify the individually optimal treatment from available alternatives in mental health and beyond. The traditional PAI compares a patient’s predicted post-treatment symptom scores across treatment alternatives to identify the treatment with the most favorable predicted score. However, clinicians may wish to select the treatment that maximizes that patient’s predicted probability of achieving a clinically defined outcome, such as remission. This study presents an Alternative PAI (AltPAI) optimized for this purpose and evaluates its performance. Methods: We used routine care data (n = 1,264) to implement the traditional PAI and AltPAI using random forests. The indices were compared regarding the benefit for patients in terms of dimensional improvement and remission. Exploratively, the PAI and AltPAI were combined into an ensemble (EnsPAI). Results: The AltPAI outperformed the PAI descriptively but not significantly, yielding higher symptom change (cohens d = 0.09) and remission probability (OR = 1.32) for optimally treated patients with higher index values. Regarding symptom improvement, the PAI performed worse than chance. The EnsPAI was the only algorithm to perform significantly better than chance in terms of symptom remission. Conclusions: The AltPAI and EnsPAI demonstrated performance that was generally descriptively superior to the PAI. The approaches should therefore be investigated in combination with the PAI in future treatment stratification analyses. Additionally, more advanced implementations of the EnsPAI are discussed that would allow the ensemble to be calibrated on the error of the base indices, potentially increasing prediction performance.
Source: PsyArXiv (OSF Preprints)
Language: English
Subfield: Health Information Management
Field: Health Professions
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7222993396