title: Do violence dynamics matter?
abstract: OBJECTIVE
  Intimate partner violence is a complex, non-linear phenomenon. The purpose of this study was to determine whether violence dynamics (pattern, degree of non-linearity, optimal non-linearity) contributed to outcomes in violent relationships.
  
  
  METHODS
  The study was conducted in six primary care clinics, enrolling 200 adult women in violent relationships. In addition to baseline and end-of-study interviews, women completed daily telephone assessments of household environment and partner violence using interactive verbal response. Three non-linearity measures of violence were computed with 'optimal' non-linearity estimated using Z-transformations. Assignment of dynamic patterns (periodic, chaotic, random) was made based upon Lyapunov exponent and correlation dimension. Outcomes across dynamic patterns were analysed using analysis of variance. In addition, stepped multiple linear regression explained factor-analysed outcomes, adjusting for demographic, childhood, mental health and marital variables; attitudinal/behavioural outcomes were also adjusted for when explaining clinical outcomes.
  
  
  RESULTS
  Women experiencing periodic violence recognized the importance of violence and used their active coping to seek mental health care. Those with chaotic dynamics recognized that they were not responsible, experienced fewer psychological symptoms and emotional role limitations, and did not seek help. Those experiencing random violence recognized its unpredictability and uncontrollability. Violence non-linearity predicted negative coping, positive appraisals and hope/support in regression analyses, while optimal non-linearity contributed to readiness for change and symptoms functioning. Of the nine outcomes investigated, violence non-linearity contributed to five outcomes.
  
  
  CONCLUSIONS
  Dynamic pattern of violence, degree of violence non-linearity and optimal non-linearity correlated with several attitudinal/behavioural and clinical outcomes. Knowledge of violence dynamics may have applications when working with violent couples.
authors.affiliation: Department of Family & Community Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: David
authors.initials: D
authors.lastname: Katerndahl
authors.forename: Sandra
authors.initials: S
authors.lastname: Burge
authors.forename: Robert
authors.initials: R
authors.lastname: Ferrer
authors.forename: Johanna
authors.initials: J
authors.lastname: Becho
authors.forename: Robert
authors.initials: R
authors.lastname: Wood
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000453:epidemiology*; D004777:Environment; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008875:Middle Aged; D017711:Nonlinear Dynamics; D011320:Primary Health Care; D012959:Socioeconomic Factors; D013179:Spouse Abuse / Q000523:psychology / Q000706:statistics & numerical data*
keywords: battered women; domestic violence; intimate partner violence; non-linear dynamics; outcomes research; systems theory