Effects of a Group-Based Cognitive Behavioral Therapy for Sleep in Nursing Students: Pilot Randomized Controlled Trial.

The largest treatment effect was observed for self-reported sleep latency, favoring the CBT-I intervention group.

• Regression coefficient β = -19.78 minutes (95% CI -33.83 to -5.74)
• Partial η² = 0.194, indicating a moderate effect size
• This was the only primary outcome where the confidence interval excluded zero, suggesting a statistically meaningful effect
• Sleep latency was assessed via the Pittsburgh Sleep Quality Index (PSQI)

Sleep duration favored the intervention group but confidence intervals indicated considerable uncertainty around the estimate.

• Regression coefficient β = 36.32 minutes (95% CI -5.01 to 77.64)
• Partial η² = 0.086, indicating a small-to-moderate effect size
• The 95% CI crossed zero, meaning the result did not reach conventional statistical significance
• Assessed using both the Kronowise 3.0 ambulatory circadian monitoring system and PSQI

Sleep efficiency favored the intervention group but also showed considerable uncertainty in the estimate.

• Regression coefficient β = 8.75% (95% CI -0.97 to 18.47)
• Partial η² = 0.090, indicating a small-to-moderate effect size
• The 95% CI crossed zero, indicating statistical uncertainty
• Adjusted analyses controlled for baseline values, smoking status, school schedule, and coffee consumption as covariates

Objective circadian rhythm and sleep outcomes showed generally small treatment effects across the intervention and control groups.

• Objective sleep was assessed using the Kronowise 3.0 ambulatory circadian monitoring (ACM) system over 7-day monitoring periods pre- and post-intervention
• The Kronowise device generated continuous circadian rhythm and sleep parameters
• Adjusted analyses used analysis of covariance (ANCOVA) with treatment group as the fixed factor
• Treatment effects were summarized using regression coefficients (β), 95% CIs, and partial eta-squared (η²)

Participants reported high satisfaction with the group-based CBT-I intervention.

• 65% (13/20) of intervention participants rated the program as 'very good'
• Satisfaction was evaluated using an adapted 12-item Likert-type satisfaction questionnaire administered after the intervention
• All 20 participants in the experimental group completed the satisfaction assessment

The study enrolled 40 first-year nursing students in a 2-arm pilot randomized controlled trial at a private university in Madrid, Spain.

• Participants were aged 18 to 25 years (mean age 19.9, SD 1.8 years)
• 85% of participants (n=34) were female
• Participants were recruited in October 2022 using convenience sampling and randomly assigned equally: experimental group (n=20) and control group (n=20)
• The experimental group received a cognitive-behavioral intervention using an active-constructive learning methodology; the control group followed their usual daily routine
• The trial was conducted from October 2022 to March 2023 and followed CONSORT guidelines

Nursing students are identified as a particularly vulnerable population group with respect to sleep quality.

• Sleep quality is described as 'a strategic public health priority and a key factor in the study of circadian rhythms and chronotypes'
• The study focused on first-year nursing students as the target population
• The study used both subjective (PSQI) and objective (Kronowise 3.0 ACM) measures to capture multiple dimensions of sleep

The authors conclude that adequately powered randomized controlled trials with longer follow-up are needed to confirm these preliminary findings.

• The pilot study was described as exploratory in nature
• The small sample size (n=40 total) limits the generalizability of results
• Wide confidence intervals around several outcome estimates reflect the limited statistical power of the pilot design
• The authors call for future trials with larger samples and extended follow-up periods