title: Sleep quality of middle-aged Tai Chi practitioners.
abstract: OBJECTIVE
  This study aimed to assess the association between Tai Chi and sleep quality in middle-aged Tai Chi practitioners.
  
  
  METHODS
  This cross-sectional descriptive study recruited a convenience sample of 250 middle-aged Tai Chi practitioners. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Descriptive statistics such as frequency and percentage were used to describe the demographic characteristics of the subjects. Pearson's product-moment correlation was used to determine the relationship between sleep quality and duration of practicing Tai Chi. anova was used to compare difference in sleep quality among subjects practicing different styles of Tai Chi. Linear regression was conducted to determine the contribution of duration of practicing Tai Chi and the style of Tai Chi being practiced to explaining sleep quality.
  
  
  RESULTS
  Subjects had practiced Tai Chi for 4.7 years. They reported a global PSQI score of 5.3. Among the subjects, 156 were classified as good sleepers (PSQI score, <5). No significant relationship was reported between sleep quality and duration of Tai Chi practice (P = 0.175). No significant differences in sleep quality were found among subjects who practiced different styles of Tai Chi (P = 0.876). Linear regression analysis indicated that the duration of practicing Tai Chi and the style of Tai Chi being practiced did not make a significant contribution to sleep quality.
  
  
  CONCLUSIONS
  The present study represented an initial attempt to investigate the sleep quality among middle-aged Tai Chi practitioners. It serves to generate hypotheses for future testing.
authors.affiliation: Division of Nursing and Health Studies, The Open University of Hong Kong, Hong Kong, China.
authors.forename: Linda Yin King
authors.initials: LY
authors.lastname: Lee
authors.forename: Ka Wai
authors.initials: KW
authors.lastname: Tam
authors.forename: Mei Lam
authors.initials: ML
authors.lastname: Lee
authors.forename: Nga Yi
authors.initials: NY
authors.lastname: Lau
authors.forename: Joanne Cho Yan
authors.initials: JC
authors.lastname: Lau
authors.forename: Yin Mai
authors.initials: YM
authors.lastname: Lam
authors.forename: Christine Hoi Wai
authors.initials: CH
authors.lastname: Lam
authors.forename: Wing Kit
authors.initials: WK
authors.lastname: Kwan
authors.forename: Daisy
authors.initials: D
authors.lastname: Chan
authors.forename: Betsy
authors.initials: B
authors.lastname: Chan
authors.forename: Paul Zoen Kit
authors.initials: PZ
authors.lastname: Chan
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012890:Sleep; D026302:Tai Ji
keywords: Tai Chi; health promotion; middle-aged people; public health; sleep quality