1. Introduction
sleep difficulties, Anxiety, sleep disturbance, fatigue, insomnia, Insomnia, Depression, Fatigue
Co-first Authors.Far infrared (FIR)-based clothing may alleviate sleep disturbance. This study aimed to explore the effects of FIR-emitting pajamas on sleep quality. This was a pilot randomized, sham-controlled trial. Forty subjects with poor sleep quality were randomized to FIR-emitting-pajamas and sham-pajamas groups in a 1:1 ratio. The primary outcome measure was the Pittsburgh Sleep Quality Index (PSQI). Other measures included the Insomnia Severity Index, and 7 day sleep diary, the Multidimensional Fatigue Inventory (MFI), the Hospital Anxiety and Depression Scale, the Epworth Sleepiness Scale, and the Satisfaction with Life Scale. Outcomes were measured at baseline and weeks 2, 4, and 6. Both groups showed within-group improvements in the PSQI score, but there was no significant difference between the two groups. However, FIR-emitting pajamas appeared to perform better than sham pajamas in reducing the MFI-physical score, with large effect sizes at three time points (dppc2 = 0.958, 0.841, 0.896); however, the differences were statistically insignificant. The intervention compliance was satisfactory. The effects of FIR-emitting pajamas on sleep quality were not superior to those in the control group. However, these pajamas may improve physical fatigue in adults with poor sleep quality, which warrants further exploration.Self-reported sleep difficulties are a highly prevalent health complaint, with a range of 10–48% of the general population worldwide experiencing sleep problems accompanied by daytime consequences [Sleep can be regulated by optimizing the environment in which one sleeps. This is achieved by controlling environmental factors, such as temperature, lighting, and noise [The effects of textiles embedded with FIR bio-ceramic technology on sleep have been examined in a pilot randomized controlled trial (RCT) by McCall and colleagues [Clothing made from FIR-based textiles could be a sustainable way to alleviate insomnia with many advantages. First, the proposed FIR textiles were composed of handmade profiled fibers without the addition of chemicals, such as ceramic additives or other related coatings. Enhanced FIR radiation absorptivity and emissivity were induced through the structural modification of the handmade fibers. Thus, the textiles were environmentally friendly and safe to wear. The pajamas made from FIR-based textiles thus had more advantages than bedsheets in relation to altering body temperature. Pajamas are worn on the body and are directly in contact with the skin. Hence, the far-infrared radiation absorptivity and emissivity, which were induced by the total internal reflection and the waves between the textiles and the skin, were more direct. This comfortable thermal environment was associated with better sleep quality. Furthermore, FIR-emitting pajamas, as an intervention with lower costs and requiring zero therapist input, can ensure longer-term sustainability of benefits compared to the traditional therapist-delivered treatment modality or self-help interventions demanding continuous effort (The specific aims of this study were as follows: (1) to evaluate the short-term effects of FIR-emitting pajamas in relation to improving insomnia symptoms compared to the sham-pajamas control group, for which we measured sleep quality using the Pittsburgh Sleep Quality Index (primary outcome) and other sleep measures; and (2) to evaluate the acceptability of using FIR-emitting pajamas to enhance sleep quality.