Population Impact of PTSD and Depression Care for Military Service Members: Reach and Effectiveness of an Enhanced Collaborative Care Intervention.

Objective: Epidemiologic studies suggest high rates of posttraumatic stress disorder ( PTSD) and depression among military members and veterans. To meet the needs of this population, evidence-based treatments are recommended as first-line interventions, based on their clinical efficacy and not the proportion of the target population that the intervention reaches. We apply a public health framework to examine the population impact of an enhanced collaborative care model on a targeted population that takes into account effectiveness and reach. Methods: Using data collected from a 2012 - 2016 randomized trial, the effectiveness of enhanced collaborative care for PTSD and depression was evaluated using probable diagnostic status as the primary outcome. Exclusion criteria were then applied to a 2011 disease registry to examine the representativeness of the trial sample and estimate the potential reach of the intervention. Population impact was derived from the estimated effectiveness and reach of the intervention. Results: Enhanced collaborative care was associated with a significantly greater probability of PTSD/depression remission by the end of the trial (conditional effect = -0.066, chisq = 51.1, p < 0.001). Based on the effectiveness and reach of the enhanced intervention, an estimated 250 (out of the 3,436) more Army soldiers with PTSD and/or depression would experience diagnostic remission during the preceding year if the enhanced model was available. Conclusion: The population framework permits the estimated differential impact of two collaborative care models to inform implementation considerations. These results highlight the value of applying public health models to identify front line treatments.