Abstract 16347: The Association of Depressive Symptoms and the Intermountain Mortality Risk Score to All-cause Mortality

Abstract

Introduction: The patient health questionnaire (PHQ)-9 is widely used for the diagnosis and assessment of depression severity, but further study is needed regarding whether it provides prognostic information for major events such as mortality. The sex-specific Intermountain Mortality Risk Score (IMRS©) is a widely-validated risk stratification tool that utilizes the complete blood count (CBC), basic metabolic profile (BMP), and age to predict all-cause mortality. Hypothesis: IMRS is associated with all-cause mortality among subgroups defined by depressive symptoms. Methods: Patients who completed a PHQ-9, were ≥40 years, and had a CBC and BMP tested as part of their clinical care were studied. Prior validated sex-specific IMRS weightings and risk stratifications of low, moderate, and high were used. Patients were stratified by depressive symptoms of none (PHQ-9 score <10), mild (PHQ-9 score 10-14), and moderate to severe (PHQ-9 score ≥15). Multivariable Cox hazard regression was performed among all patients and within strata defined by depressive symptoms to determine associations of IMRS and depressive symptoms with all-cause mortality. Results: A total of 11,583 females (age: 58.7±12.7 years) and 7,814 males (age: 59.9±12.5 years) were evaluated. Both PHQ-9 and IMRS stratifications were associated with all-cause mortality in a step-wise manner, which persisted despite multivariable adjustment (Table). In categories defined by depressive symptoms, IMRS markedly stratified risk of mortality (Table). Conclusion: IMRS and severity of depression were independent predictors of mortality risk among patients screened for depression. Further, IMRS was a powerful predictor of mortality within each level of depressive symptoms. This study suggests a need to evaluate IMRS as a tool for informing clinical risk stratification among patients with symptoms of depression and directing additional resources to those at highest risk of major adverse events.