Concilio 2021.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group
Participants	Baseline characteristics Text messaging (Social Support Behavioral Code) Age (range in years): NR Sex (N (% female)): NR Sample size: 11 Years of experience (mean ± SD): NA Control (text messaging ‐ medical facts) Age (range in years): NR Sex (N (% female)): NR Sample size: 11 Years of experience (mean ± SD): NA Overall Age (range in years): 21 to 30 Sex (N (% female)): 20 (95%) Sample size: 22 Years of experience (mean ± SD): NA Included criteria: eligibility criteria were: (a) NLGNs employed as RNs for the first time, (b) ages 19 to 37 years (millennials and post‐millennials) as the majority joining the workforce (NursingLicensure.org, 2020), (c) proficient in English, (d) working in an acute care facility as an RN during the first year of hire, (e) had a working personal smartphone, (f) had the ability to send and receive text messages, (g) had an active and working personal email account, (h) were willing to participate for 6 weeks, (i) completed survey instruments at baseline, week 3, and week 6, (j) agreed to not use or carry their smartphone while performing direct patient care, and (k) assumed any data charges for text messages Excluded criteria: exclusion criteria were NLGNs who had worked as an RN on another floor or at another organisation Pretreatment: NR Compliance rate: Response rate: 100% Type of healthcare worker: exclusively nurses who were in their first year of hire.
Interventions	Intervention characteristics Text messaging (Social Support Behavioral Code) Type of the intervention: 3. Intervention type 3 ‐ to focus on work‐related risk factors on an individual level. Description of the intervention: Week 1: Emotional support March 23: Monday: quote: “Speak with someone this week who understands or knows you well.”Week 3: Esteem support April 6: Monday: quote: “Always do your best so you can be proud that you gave it your best shot." Week 5: Network support April 20: Monday: quote: “Connect with others who share your specialty and with other newly licenced nurses: https://nurse.org/orgs.shtml to find your nursing organization to find your nursing organization". The number of sessions: 24 unique text messages Duration of each session on average: NA Duration of the entire intervention: 6 weeks Duration of the entire intervention short vs long: Short Intervention deliverer : NR Intervention form: Text messages Control (text messaging ‐ medical facts) Type of the intervention: Control Description of the intervention: Week 1 Monday: “DVT usually affects the deep veins of the legs” (MedlinePlus.gov, 2017) Week 3Monday: “An ostomy is surgery to create an opening (stoma) from an area inside the body to the outside. It treats certain diseases of the digestive or urinary systems. It can be permanent when an organ must be removed” (MedlinePlus.gov, 2017) Week 5 Monday: “If you have diabetes, your blood glucose, or blood sugar, levels are too high. Over time, this can damage the covering on your nerves or the blood vessels that bring oxygen to your nerves. Damaged nerves may stop sending messages or may send messages slowly or at the wrong times” (MedlinePlus.gov, 2017). The number of sessions: 24 unique text messages Duration of each session on average: NA Duration of the entire intervention: 6 weeks Duration of the entire intervention short vs long: Short Intervention deliverer: NR Intervention form: Text messages
Outcomes	Perceived Sense of Stress (PSS) Outcome type: Continuous Outcome
Identification	Sponsorship source: NR Country: USA Setting: two urban health care systems located in western Pennsylvania and southern California. Comments: NR Authors name: Lisa Concil Institution: Lecturer and Clinical Instructor, San Diego State University Email: 10006 Maya Linda Road, #5207, San Diego, CA 92126 Address: lconcilio@sdsu.edu Time period: NR
Notes	PSS included in analysis 3.1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was conducted using an online random sequence generator (Random.org, 2019)."
Allocation concealment (selection bias)	Unclear risk	Quote: "A $20 gift card was sent to participants who completed the study requirements. Additionally, the first four participants who completed the study at the end of week 6 were awarded another $50 gift card." We assume that consecutive nurses were randomised. Difficult to judge whether nurses or the investigator could possibly foresee assignment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Unclear whether participants were blinded. The control group received 'placebo' text messages.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear whether participants were blinded whereas outcomes were self‐reported. The control group received 'placebo' text messages.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rate is low. (21/22 were included in the analysis). Reason provided. Not reported whether the participant that was lost to follow‐up differed from the other participants.
Selective reporting (reporting bias)	Unclear risk	No trial registration or no study protocol reported, nor did we find one online. No indication of selective reporting.
Other bias	Unclear risk	Not reported whether there were any baseline differences between groups on stress, gender, age.