Harrer 2018.

Methods	Study design: RCT Study grouping: parallel group Unit of randomisation: individuals Power (power & sample size calculation, level of power achieved): The sample size allowed the detection of effect sizes of d = 0.41 with a power (1− β) of 0.80 with α of.05 and was based on a meta‐analysis on internet‐based interventions for college students, which reported an SMD of 0.73 for stress but lower effects for depression outcomes (SMD = 0.43). A sample size of 150 was therefore chosen to detect significant changes for secondary outcomes in this study such as depression Imputation of missing data: Analyses based on the intention‐to‐treat (ITT) principle were conducted, with missing data imputed using a Markov chain Monte Carlo multivariate imputation algorithm with 100 estimations per missing and all variables set as predictors for imputation. Imputed datasets were then aggregated to obtain 1 imputed dataset; completer analysis + ITT analysis
Participants	Country: Germany Setting: internet‐ and app‐based intervention Age: mean = 24.1 (SD = 4.1) years Sample size (randomised): 150 Sex: 112 women, 38 men Comorbidity (mean (SD) of respective measures in indicated, if available) at baseline: depression (CES‐D; 0 ‐ 45) : IG: 24.31 (9.06), CG: 23.97 (8.63); anxiety (Spielberger STAI; 6 ‐ 24): IG: 16.05 (3.37), CG: 15.77 (4.22); emotional exhaustion (MBI; 5 ‐ 30): IG: 21.63 (4.49), CG: 22.27 (4.31); 106 participants (76.8%) indicated that they were first‐time help‐seekers; 77.3% (IG: 58/75; CG: 58/75) showed clinically relevant depressive symptoms at baseline Population description: college students at German‐speaking universities with elevated levels of stress (PSS‐4 ≥ 8) Inclusion criteria: 1) elevated levels of perceived stress (PSS‐4 ≥ 8; representing a level of stress one SD = 2.92 above the mean of 4.49 in a large student sample); 2) enrolment in a German‐speaking university at the beginning of the training; 3) age ≥ 18 years; 4) internet access; 5) willingness to provide self‐report data at all assessment points; 6) informed consent Exclusion criteria: 1) self‐reported diagnosis of dissociative symptoms or psychosis in the past; 2) considerable risk for suicide (BDI item 9 > 1; “I feel I would be better off dead” or “I would kill myself if I had the chance”) Attrition (withdrawals and exclusions): post‐intervention: 11 lost to assessment (all in IG, 14.7%); all participants in CG (n = 75) provided data; follow‐up: 45 lost to assessment (IG: 35/46.7%, CG: 10/13.3%) Reasons for missing data: not specified for 56 lost to assessment/follow‐up at different assessments
Interventions	Intervention: TAU + StudiCare Stress (n = 75) delivery: StudiCare Stress: internet‐ and mobile‐based training with feedback on demand personal diary app could be downloaded by participants Before beginning with the intervention, participants could request automatic daily messages containing short motivational prompts and ultrabrief training exercises by SMS (short message service), aimed at facilitating transfer of learned strategies into daily life routine providers: participants guided by eCoach, a trained student in a master’s programme in psychology contact between eCoach and intervention participants solely established online (no face‐to‐face meeting) guidance consisted of 3 parts: (1) monitoring adherence (sending up to 3 reminders when a module was not completed during 1 week through the internal platform messaging system and by email), (2) checking the intervention platform back‐end for participants who had completed a new module to unlock the next module and send standardised motivational messages through the platform (3) providing feedback on demand When requesting help, participants received feedback within 48 hours feedback reflected participants’ individual questions and problems and gave positive reinforcement feedback on demand available for each participant from module 1 until completion of the booster session and was given by the internal messaging system of the training platform duration of treatment period and timing: eight main 30‐ to 90‐minute modules; participants advised to complete at least 1 and maximum of 2 modules a week; i.e. intervention intended to be completed in about 5 ‐ 7 weeks; participants instructed to monitor their mood 2 to 3 times each week, using either the app or a printout of the PDF for their entries description: TAU: routine health care StudiCare Stress: 8 main modules SESSION 1: INTRODUCTION: psycho‐education, information about stress and preview of subsequent sessions SESSION 2: PROBLEM‐SOLVING: stress management strategies, systematic problem‐solving using a 6‐step individualised problem‐solving heuristic SESSION 3: MUSCLE‐ AND BREATH RELAXATION: recap and modification of the problem‐solving heuristic, information on basic principles of muscle and breath relaxation, audio exercises for daily usage SESSION 4: MINDFULNESS: recap of muscle‐ and breath relaxation and addition of detached mindfulness components into the routine, metacognitive strategies for dealing with self‐criticism SESSION 5: ACCEPTANCE AND TOLERANCE: recap of metacognitive strategies, dealing with unsolvable problems, psycho‐education on and exercises for acceptance and tolerance of unpleasant emotions SESSION 6: SELF‐COMPASSION: fostering self‐compassion in precarious situations, defusion of self‐worth and performance, writing a self‐compassionate letter, cognitive restructuring to overcome dysfunctional perfectionistic thought‐action patterns SESSION 7: MY MASTER PLAN: recognising physical warning signs, recap of coping strategies for solvable and unsolvable stressors, creating a plan for the future SESSION 8: BOOSTER SESSION: further information on self‐help and psychotherapy, evaluation of training transfer, recap of all sessions, repetition of previous exercises, finding future directions for development Elective modules integrated at the end of sessions 2 to 7 could be chosen based on individual need and interest, covering student‐specific topics: social support, rumination and worrying, time management, procrastination, test anxiety, sleep, motivation, nutrition and exercise, and dealing with writer’s block and concentration: SOCIAL SUPPORT: communication styles, receiving and providing support RUMINATION & WORRYING: reflection on positive and negative aspects of worry, coping with uncertainty TIME MANAGEMENT: effective time scheduling, common planning fallacies, learning to prioritise procrastination Identifying situations in which procrastination occurs, strategies to reduce procrastination TEST ANXIETY: effective studying techniques, using paradoxical intentions, de‐catastrophising blackouts SLEEP: sleep restriction MOTIVATION: finding reasons for lacking motivation, exercising delay of gratification NUTRITION & EXERCISE: creating an individual eating and exercise schedule, dealing with relapses DEALING WITH WRITER'S BLOCK: reasons and coping strategies for writer’s block CONCENTRATION: audio‐based concentration exercises strong emphasis on transfer of acquired knowledge, strategies, and techniques into the students’ daily life through homework assignments general structure of app‐based diary entries: How do you feel today? (emoticons: happy–sad–anxious–angry) How stressed out do you feel today? (rating scale 1 ‐ 10) Describe what happened today. (free text) Were you able to identify any things contributing to your stress levels today? (free text) Are there any techniques you previously learned that you may be able to apply? (free text) Do you want to add a photo to your entry? (upload button) compliance: On average, participants in the IG completed 5.05 modules (SD 2.78), which equals 72.1% of the intervention; participants completed optional add‐on modules in most sessions (82.1%) in which they were available; most participants completed rumination & worrying (59%, 44/75), whereas only 8 of the 75 participants completed social support (11%) 46 of the 75 participants in the IG (61%) downloaded and logged into the diary app at least once Activation of the automated SMS messages was requested by 4 of 75 participants in the IG (5%) during the study Very few participants (5%, 4/75) requested individual feedback, resulting in 5 content feedbacks for the entire sample. The eCoach sent 289 reminders (3.85 reminders per participant) integrity of delivery: not specified economic information: not specified theoretical basis: based on cognitive‐behavioural and third‐wave techniques and aligns with Lazarus’ transactional model of stress in differentiating between problem‐focused and emotion regulation–focused coping derived from GET.ON Stress, a Web‐based stress management intervention for employees Control: TAU + wait‐list control (n = 75) delivery: for TAU not specified providers: TAU offered by routine health care duration of treatment period and timing: for TAU not specified description: were not given access to intervention until 3 months after randomisation, but had full access to TAU compliance: not specified integrity of delivery: for TAU not specified economic information : for TAU not specified theoretical basis: for TAU not specified
Outcomes	Outcomes collected and reported: Primary outcome: perceived stress ‐ PSS‐4 Secondary outcomes: Mental health: depression ‐ CES‐D state anxiety ‐ STAI well‐being/overall marker of mental health ‐ WHO‐Five Well‐Being Index emotional exhaustion ‐ subscale MBI Risk and protective factors: dysfunctional perfection ‐ Revised Almost Perfect Scale resilience ‐ CD‐RISC‐10 self‐compassion ‐ SCS self‐esteem ‐ RSES College‐related outcomes: academic work impairment (presenteeism and loss of productivity) ‐ Presenteeism Scale for Students subscale for work impairment (Work Impairment Scale) academic productivity losses ‐ adaption of the Presenteeism Scale for Students’ work output scale (current percentage to which participants were able to reach usual academic productivity) academic self‐efficacy ‐ academic self‐efficacy scale academic worrying ‐ Academic Worrying Questionnaire Additional measures: demographic variables prior contact with professional health providers ‐ not reported satisfaction with intervention (only IG) ‐ Client Satisfaction Questionnaire adapted to web‐context treatment credibility and expectancies ‐ Credibility and Expectancy Questionnaire Time points measured and reported: 1) pre‐intervention; 2) post‐intervention; 3) 5‐week follow‐up (at 3 months after randomisation; i.e. 5 weeks after end of 7‐week intervention); treatment credibility and expectancies only measured at pre‐intervention Adverse events: not specified
Notes	Contact with authors: We contacted the authors for information on whether the intervention focused on fostering resilience and if healthcare students were included in the sample, but received no response Study start/end date: 9 May 2016 (start of recruitment) ‐ 30 January 2017 (follow‐ups completed) Funding source: partly funded by BARMER (major healthcare insurance company in Germany) Declaration of interest: Daniel David Ebert (DDE) reports to have received consultancy fees or served in the scientific advisory board from several companies such as Minddistrict, Lantern, Schön Kliniken, and German health insurance companies (BARMER, Techniker Krankenkasse). DDE and Mathias Harrer are also stakeholders of the Institute for health trainings online (GET.ON), which aims to implement scientific findings related to digital health interventions into routine care. Harald Baumeister reports to have received consultancy fees and fees for lectures or workshops from chambers of psychotherapists and training institutes for psychotherapists. In the past 3 years, Ronald C Kessler (RCK) received support for his epidemiological studies from Sanofi Aventis, was a consultant for Johnson & Johnson Wellness and Prevention, Sage Pharmaceuticals, Shire, Takeda, and served on an advisory board for the Johnson & Johnson Services Inc, and Lake Nona Life Project. RCK is a co‐owner of DataStat, Inc, a market research firm that carries out health care research. Ethical approval needed/obtained for study: approved by the University of Erlangen‐Nuremberg ethics committee (Erlangen, Germany; 322_15 B) Comments by study authors: study carried out as part of the WHO World Mental Health International College Student project; trial registration number: German Clinical Trial Register DRKS00010212; website, studicare.com Miscellaneous outcomes by the review authors: According to the feedback from the authors in another trial (DRKS00011800) using an intervention (StudiCare Fernstudierende) that is adapted from the intervention investigated here (StudiCare Stress), the intervention also aims to foster health‐promoting factors (secondary outcomes), such as resilience and the reduction of perceived stress; but unclear if healthcare students were included in the final sample Correspondence: Mathias Harrer, BSc; Clinical Psychology and Psychotherapy; Friedrich‐Alexander‐University Erlangen‐Nuremberg, Nägelsbachstraße 25a, Erlangen, 91052, Germany; mathias.harrer@fau.de; Phone: 49 1708237654