Participants.
The present study included patients treated with the MHP, an evidence-based therapist-supported DMH intervention. In the United States, Meru Health operates a professional corporation in California and Florida and has been treating patients since 2018. In the present study, all data came from recruited participants in the United States who started the program on or after January 1, 2020 and an end date on or before December 1, 2020. We used June 1, 2021 as a cut-off to allow for inclusion of patients able to complete the 12-week treatment program and have a 6-month follow-up in our dataset (i.e., time since December 1, 2020). Participants were 778 patients, aged 19-63 (see Table 1).
Table 1
Meru Health Program Participant Demographic and Clinical Characteristics
Variable | N | Percentage | Mean (SD), Range |
Age | 778 | | 40 (11.2), 19-82 |
Sex | | | |
Female | 600 | 77.12% | |
Male | 177 | 22.75% | |
Other | 1 | 0.13% | |
Baseline PHQ-8 Severity | 218 | | 11.1 (5.9) |
Less than Mild | 117 | 15.04% | |
Mild | 222 | 28.53% | |
Moderate | 187 | 24.04% | |
Moderately Severe | 182 | 23.39% | |
Severe | 70 | 9.00% | |
MDEs | | | |
None | 376 | 48.33% | |
First | 114 | 14.65% | |
Recurrent | 288 | 37.02% | |
Taking Psychiatric Medication | | | |
Yes | 334 | 44.22% | |
No | 434 | 55.78% | |
Lifetime Suicide Attempt | | | |
Yes | 35 | 4.50% | |
No | 743 | 95.50% | |
Lifetime Psychiatric Hospitalization | | | |
Yes | 39 | 5.01% | |
No | 739 | 94.99% | |
Lifetime History of Major Traumatic Event Exposure | | | |
Yes | 327 | 42.03% | |
No | 435 | 55.91% | |
Unknown | 16 | 2.06% | |
Notes: MDE = Major Depressive Episode; PHQ = Patient Health Questionnaire |
Symptom severity is measured by baseline PHQ-8 score as follows: less than mild=0-4, mild=5-9, moderate=10-14, moderately severe=15-19, severe=20+. |
Recruitment.
Participants entered the MHP via referrals from employee assistance programs or via their healthcare providers. All enrolled patients signed informed consent to participate and to have their collected and deidentified data used for research purposes. Inclusion/exclusion criteria of the MHP required patients to have at least mild levels of depression, anxiety, or burnout, own a smartphone, and not have an active substance use disorder, severe active suicidal ideation with a specific plan, severe active self-harm, or a history of psychosis or mania.
All patients enrolled signed informed consent to participate and have their collected, de-identified data used for research purposes. Data collected as part of care is stored in Health Insurance Portability and Accountability Act-compliant electronic medical records that includes protected health information. All data are encrypted in transit, and at rest. Institutional review board exemption for this analysis was obtained from the Pearl Institutional Review Board (#21-Meru-113) for analyses of previously collected and de-identified data.
Meru Health Program (MHP) Treatment.
After the informed consent procedure, patients were enrolled in the MHP. Created in 2017, the MHP has been described in detail in prior publications (41, 42). In sum, the MHP is composed of several different evidence-based components or processes of evidence-based therapies delivered via a smartphone app. The program is self-guided but incorporates a stepped and continuous care model that includes daily interaction with a dedicated, licensed clinical therapist and a medical doctor and psychiatrist available for consultation as needed. The program lasts 12 weeks and contains components of Cognitive Behavioral Therapy (43), Behavioral Activation Therapy (44), and Mindfulness-Based Stress Reduction (45), and Mindfulness-Based Cognitive Therapy (46), sleep therapy (47), nutritional psychiatry components (48), heart rate variability biofeedback (49).
Prior to the start of the MHP, participants are trained on how to use the app, including how to participate in the anonymous group interaction and how to communicate with their assigned therapist via chat or phone/video calls. Each week of the program begins with an introductory video that gives the patient an overview of the topics covered that week. Patients are prompted to complete various practices, mostly CBT exercises and journal prompts, as well as short audio-guided mindfulness meditation exercises on a daily or almost daily basis. Daily content and practices range from 5-15 minutes, except for the first day of each week, in which the weekly psychoeducation video lessons extend the content to a maximum of 25 minutes.
A licensed therapist (employed by Meru Health) provides support to participants via messaging (and less frequently, phone or video calls) as needed, and reviews practice logs using a provider “dashboard” and electronic medical records that detail individual progress (including participant engagement and patient-reported outcomes to date). In total, therapists allocate approximately 10-20 minutes (on average) per week per participant. Interaction between therapist and participant can be initiated via either party.
As a safety measure, therapists conduct a phone-based protocol assessment for any participants that show signs of mental deterioration during the intervention. In case of an emergency, such as having SI with intent to act or onset of psychotic symptoms, the intervention includes a written action plan for declining mental health, which all participants are required to review with their therapist prior to engaging with the intervention. In these situations, the care coordination-therapist team at Meru Health will help connect the patient to immediate and local care outside of the program, however, a psychiatrist employed by Meru Health is available for consultation in these situations as well.
Patients complete the MHP as a cohort of typically 8-15 patients. As such, cohorts can interact anonymously when sharing their practice experiences, such as providing and receiving support and feedback on their experiences as they navigate the MHP. Direct communication between participants, however, is not allowed. Instead, participants can post anonymous reflections on practices and lessons to the chat discussion board, to which their therapist can respond freely, and to which other group members can respond with pre-written empathy statements and/or emoticons.
Measures. All measures examined in this study were collected in the MHP app at baseline (before the start of the MHP), biweekly during the MHP including at end-of-treatment, and via email at 3- and 6-month post-treatment.
Patient Health Questionnaire- (PHQ-9). Participants completed the PHQ-9 in order to calculate PHQ-8 depressive symptoms and to assess SI with the 9th item. The PHQ-8 is comprised of all PHQ-9 items, except for the 9th item on SI, and is a list of eight depressive symptoms with response options ranging from 0 (not at all) to 3 (nearly every day). Each symptom is assessed with the stem question, “Over the last 2 weeks, how often have you been bothered by any of the following problems?” The PHQ-9 is a widely used instrument used to screen for depression (50). We used the first 8 items of the PHQ-9 to calculate the PHQ-8, which assessed purely depressive symptoms without the last PHQ-9 item that assesses SI (51). We coded treatment baseline PHQ-8 symptoms using categories established for the PHQ-9 with the 9th item removed as None/Minimal (0-4), Mild (5–9), Moderate (10–14), Moderately Severe (15–19), and Severe (20–24) to assess baseline depression severity, with knowledge that this method could lead to a slightly lower proportion of patients categorized as having moderately severe or severe depression (51).
The primary outcome of interest is the last item of the PHQ-9 to assess suicidal ideation. This item asks whether participants have experienced, “Thoughts that you would be better off dead, or thoughts of hurting yourself in some way?” on a scale from 0- not at all, 1- Several days, 2- More than half the days, 3- Nearly every day.
Calculation of Reduction in Lives Lost. We used risk data from Rossom et al. (2017) (23) to calculate estimated reductions in suicide attempts and death by suicide. Based on these findings for 0 (not at all) there is a 0.40% of suicide attempt and 0.03% of suicide death risk, 1 (several days) there is a 1.60% of suicide attempt and 0.12% of suicide death risk, 2 (more than half the days) there is a 2.80% of suicide attempt and 0.21% of suicide death risk, and for 3 (nearly every day) there is a 4.00% of suicide attempt and 0.30% for suicide death risk.
Covariates. Participant age, sex, program engagement as measured by the number of days active each two week period during the 12 week program, severity category of PHQ-8 assessed depressive symptoms, number of self-reported lifetime major depressive episodes (none, first episode, or recurrent), lifetime suicide attempts (self-reported), lifetime prior psychiatric hospitalization (self-reported), lifetime exposure to a major traumatic event (self-reported), and current psychotropic medication use (self-reported) were used as covariates.
Statistical Analysis.
All statistical analyses were conducted with RStudio, Version 1.3.959. The study was preregistered on Open Science Framework (https://osf.io/eug8w/). Statistical significance was defined using 95% confidence intervals and p-values. Exploratory analyses including histograms as well as skew and kurtosis statistics were run for each variable to check for normality and any variable that then had a skew of +/- 2 was log transformed, except for the PHQ-9 item 9 (skew = 3.81). Descriptive statistics (i.e., n and percentages or mean and standard deviations) were calculated for each patient demographic and clinical variable (see Table 1). Outcome measures were analyzed using an intention-to-treat (ITT) analysis in which all participants with outcome measures at baseline were included, regardless of intervention engagement or attrition. Approximately 12.7% of data were missing from the final sample (note this study used ITT, so we included all treatment weeks 0-12 and 3- and 6-month follow-up data as missing for participants that dropped out). To assess whether data were missing completely at random (MCAR) we performed a parametric (p < 0.001) test using the Naniar package (52). Despite that data were not MCAR, based on recent recommendations (53, 54), in order to account for missing data, we performed multiple imputation (10 imputations) using the mice package (55) (see Supplemental Material for missing data by variable and treatment week).
First, we examined the impact of treatment week on SI by conducting a multilevel model (MLM) that nested treatment week (Level-1) within individuals (Level-2) across a linear model and Poisson and negative binomial models to account for the skewed distribution of PHQ-9 Item 9 response (skew=3.81). We used used the lme4 package (56) for linear and negative binomial models and the glmmTMB package (57) for the Poisson model. Fixed effects including covariates were tested at the level of participants (Level-2). This statistical approach accounts for dependency within participants and introduces less bias due to missing data compared to traditional statistical analyses, such as repeated measures of analysis of variance (58–60). We tested concurrent associations between treatment week and SI during the same week (Level-1).
Second, we used ggstatsplot package (61) to conduct a nonparametric Friedman Test, an alternative to a repeated measures ANOVA for nonnormal data, to determine whether there were significant reductions in SI between pre-treatment and post-treatment, 3-month, and 6-month follow-ups. We then used the rstatix package (62) to conduct nonparametric paired samples Wilcoxon Test contrasts that were corrected for multiple comparisons using the Holm Method (63) to determine whether there was a significant reduction in between pre-treatment and post-treatment, 3-month, and 6-month follow-ups.
Third, we performed frequency statistics on the response options of the last item of the PHQ-9 at pre-treatment and post-treatment to calculate count and percentage of participants in each response option group. We then used suicide attempt and death by suicide data from Rossom et al., (2017) (23) to calculate estimated suicide attempts and death by suicide at pre-treatment, post-treatment, 3-month, and 6-month follow-ups. The percent reduction in suicide attempts and death by suicide at post-treatment timepoints was calculated with the following equation: (pre-treatment percent - post-treatment percent)/pre-treatment percent*100. We used the equation 1/(pre-treatment percent-post-treatment percent) to calculate the number needed to treat (NNT) for both suicide attempts and deaths by suicide outcomes.