Exploring Optimal Cut-Offs of the MMPI-3 Substance Use Scale in Patients Seeking Metabolic and Bariatric Surgery

Introduction: Patients seeking metabolic and bariatric surgery (MBS) complete presurgical psychological assessments to identify potential factors that may impede surgical outcomes. Presurgical psychological assessments often screen for alcohol and substance use disorders and the Minnesota Multiphasic Personality Inventory – 3 (MMPI-3) is well suited to assess for problematic alcohol or substance use. Given the potential negative health outcomes associated with problematic alcohol/substance use in patients undergoing MBS, the recommended T-score cutoff of 65T or higher may not be optimal for identifying MBS candidates at a greater likelihood of clinically elevated symptomology – especially given its face validity. The purpose of the present study was to optimize the use and accuracy of the MMPI-3 Substance Use (SUB) scale for use with patients undergoing MBS. Method A sample of 1,257 participants from an academic medical center in the Midwest seeking MBS who produced a valid MMPI-3 protocol and had a retrospective chart review coded were included in the present study. Relative risk ratios (RRRs) were calculated to quantify the likelihood of various alcohol/substance use criteria being present at various MMPI-3 SUB scale score cut-offs. Results Optimal T-score cutoffs on the SUB scale ranged between 52T-58T, with 54 as the most commonly identified cutoff score that yielded the highest relative risk for problematic alcohol/substance use. Conclusions The recommended interpretation of the SUB scale at 54T would allow clinicians to more optimally capture those with current/past alcohol/substance problems and provide them with the appropriate pre/post-operative care if needed.