Persistent Relief: Protocol for a Feasibility Randomized Trial Comparing Yoga to Pain Education for Patients With Persistent Post-Surgical Pain.

Preterm birth, which is defined as delivery occurring prior to 37 weeks of gestation, constitutes a critical public health issue worldwide (, ). Substantial advances in perinatal medicine and neonatal intensive care have significantly improved the survival rate of preterm infants, thereby shifting research priorities from immediate postnatal survival to long-term neurodevelopmental and psychosocial outcomes. Preterm birth is increasingly recognized as a key factor associated with impaired psychosocial development in children (, ). Early childhood is a period of high neural plasticit, during which early adverse physiological experiences and environmental factors may influence neurodevelopmental pathways, profoundly affecting psychosocial outcomes and long-term adaptive functioning (). This has implications not only for immediate social integration but also for future academic achievement and overall mental health outcomes. Although the negative impact of preterm birth on psychosocial development is well-documented (–), its specific manifestations and influencing factors require further investigation. Current evidence suggests that preterm children may exhibit behavioral difficulties in childhood (–) A longitudinal study of 296 Australian children found that those born moderate-to-late preterm (32–36 weeks) had significant neurodevelopmental challenges at age 9 compared to those born ≥37 weeks (). These included lower full-scale IQ, poorer academic performance in mathematics and reading, and more behavioral difficulties (). Early developmental delay at age 2 was a strong predictor of later school-age impairments, suggesting that early screening can help identify at-risk children (). Children born extremely preterm (<28 weeks) face high risks of neurodevelopmental impairments (cognitive, motor, behavioral), affecting school performance and health (). However, preterm children also face significant socio-emotional challenges, including reduced accuracy in recognizing positive facial emotions and poorer social and behavioral outcomes compared to full-term peers. Early difficulties in emotion recognition correlate with later socio-emotional functioning (). Studies also indicate altered stress responses in preterm infants, characterized by muted emotional reactivity and uncoupling of cortisol and behavioral responses (). These deficits often persist into school age, with many preterm children showing impaired emotion recognition and social cognition, potentially linked to socioeconomic and environmental factors. Early identification and support are crucial (, , ). Furthermore, preterm children face unique social interaction challenges, with a significantly elevated risk of autism spectrum disorder (ASD) and potentially distinct clinical features compared to non-preterm children with ASD (, ). However, existing studies often report inconsistent results and are predominantly based on Western populations. Given the substantial influence of culture, region, and healthcare systems on psychosocial development, large-scale, representative epidemiological studies on preterm preschoolers in China—particularly in less developed western urban regions—remain scarce. This study was conducted in a major urban center in Western China to provide region-specific evidence from an area with evolving healthcare resources. To fill this research gap, we carried out a large-scale cross-sectional study in a city located in Western China, aiming to explore the association between preterm birth and psychosocial outcomes among preschool-aged children. Using a stratified cluster sampling approach, 20,913 parent–child dyads were recruited from 189 kindergartens. Children's psychosocial functioning was evaluated via the parent-reported Strengths and Difficulties Questionnaire (SDQ), which encompasses four dimensions: total difficulties, internalizing problems, externalizing problems, and prosocial behavior (, ). Multivariable logistic regression models were employed to analyze the independent association between preterm birth and various psychosocial outcomes, adjusting for potential confounders such as parental and child demographic characteristics, family socioeconomic status, and parental health behaviors. Stratified interaction analyses were conducted to explore whether key sociodemographic and behavioral factors showed statistical interactions with these associations (i.e., effect modification on the multiplicative scale), assessed via interaction terms in multivariable logistic regression models.