title: Substance use disorder treatment retention and completion: a prospective study of horse-assisted therapy (HAT) for young adults.
abstract: BACKGROUND
  Keeping substance use disorder patients actively engaged in treatment is a challenge. Horse-assisted therapy (HAT) is increasingly used as a complementary therapy, with claimed motivational and other benefits to physical and psychological health. This naturalistic study aimed to assess HAT's impact on the duration and completion of treatment for young substance users at Oslo University Hospital.
  
  
  METHODS
  Discharge and other data were derived from the Youth Addiction Treatment Evaluation Project (YATEP) database for patients (n = 108) admitted during an 18-month period. An intention-to-treat design, and univariate and multivariate analyses were used to compare those receiving treatment as usual (n = 43) with those who received treatment as usual plus HAT (n = 65).
  
  
  RESULTS
  Despite a lack of randomization, the baseline characteristics of the two groups were similar. However, more HAT participants completed treatment (56.9 vs 14 %, p < 0.001), remained in treatment for longer (mean 141 vs 70 days, p < 0.001) and had a significantly higher chance of completing their treatment than those not given the HAT program. Excluding time in treatment, and after controlling for the potentially confounding influence of age, sex, education, number and severity of substances used, psychological distress and number of temporary exits, the adjusted odds ratio for treatment completion was 8.4 in the HAT group compared with those not participating in HAT (95 % CI 2.7-26.4, p < 0.001).
  
  
  CONCLUSIONS
  The study found a statistically significant association between HAT participation and time in treatment, and between HAT participation and completion of treatment. This association does not infer causality. However, it adds supporting evidence for the development of an innovative therapy, and warrants investment in further research in relation to its inclusion in substance use disorder treatment.
authors.affiliation: Department of Addiction Treatment, Oslo University Hospital, Sognsvannsveien 21, Building 22, 0424, Oslo, Norway. ann@godal.com.
authors.forename: Ann
authors.initials: A
authors.lastname: Kern-Godal
authors.affiliation: Department of Addiction Treatment, Oslo University Hospital, Sognsvannsveien 21, Building 22, 0424, Oslo, Norway. esarne@ous-hf.no.|Department of Psychology, University of Oslo, Oslo, Norway. esarne@ous-hf.no.
authors.forename: Espen Ajo
authors.initials: EA
authors.lastname: Arnevik
authors.affiliation: Department of Addiction Treatment, Oslo University Hospital, Sognsvannsveien 21, Building 22, 0424, Oslo, Norway. espwal@ous-hf.no.
authors.forename: Espen
authors.initials: E
authors.lastname: Walderhaug
authors.affiliation: Norwegian Centre for Addiction Research (SERAF), University of Oslo, Oslo, Norway. edle.ravndal@medisin.uio.no.
authors.forename: Edle
authors.initials: E
authors.lastname: Ravndal
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000529:Complementary Therapies / Q000379:methods*; D005260:Female; D006736:Horses; D006801:Humans; D008297:Male; D008603:Mental Health; D009664:Norway; D010351:Patient Discharge; D011446:Prospective Studies; D011788:Quality of Life; D019966:Substance-Related Disorders / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult