Optimizing a self-directed mobile mindfulness intervention for improving cardiorespiratory failure survivors' psychological distress (LIFT2): Design and rationale of a randomized factorial experimental clinical trial

INTRODUCTION: Although as many as 75% of the >2 million annual intensive care unit (ICU) survivors experience symptoms of psychological distress that persist for months to years, few therapies exist that target their symptoms and accommodate their unique needs. In response, we developed LIFT, a mobile app-based mindfulness intervention. LIFT reduced distress symptoms more than either a telephone-based mindfulness program or education control in a pilot randomized clinical trial (LIFT1). OBJECTIVE: To describe the methods of a factorial experimental clinical trial (LIFT2) being conducted to aid in the development and implementation of the version of the LIFT intervention that is optimized across domains of effect, feasibility, scalability, and costs. METHODS AND ANALYSIS: The LIFT2 study is an optimization trial conceptualized as a component of a larger multiphase optimization strategy (MOST) project. The goal of LIFT2 is to use a 2 × 2 × 2 factorial experimental trial involving 152 patients to determine the ideal components of the LIFT mobile mindfulness program for ICU survivors across factors including (1) study introduction by call from a therapist vs. app only, (2) response to persistent or worsening symptoms over time by therapist vs. app only, and (3) high dose vs. low dose. The primary trial outcome is change in depression symptoms 1 month from randomization measured by the PHQ-9 instrument. Secondary outcomes include anxiety, post-traumatic stress disorder, and physical symptoms; measures of feasibility, acceptability, and usability; as well as themes assessed through qualitative analysis of semi-structured interviews with study participants conducted after follow up completion. We will use general linear models to compare outcomes across the main effects and interactions of the factors.