title: Transition probabilities for four states of alcohol use in adolescence and young adulthood: what factors matter when?
abstract: OBJECTIVE
  Risky single-occasion drinking (RSOD) is a health threat, particularly at younger ages. The study aimed to quantify transition probabilities (TPs) between abstinence, use of alcohol, RSOD and frequent RSOD, and to understand how TPs are associated with key demographic factors.
  
  
  METHODS
  Cohort study (baseline, two follow-ups). A Markov model was fitted to estimate annual TPs and hazard ratios (HRs) for age, sex and socio-economic status (SES).
  
  
  METHODS
  Adolescent and young adult general population of Munich (Germany) and surrounding areas.
  
  
  METHODS
  A total of 3021 people aged 14-25 years at baseline in 1995 followed-up in 1998/1999 (n = 2548) and 2003-2005 (n = 2210).
  
  
  METHODS
  Alcohol use, RSOD status, age, sex and SES (subjective financial situation) were assessed in a standardized interview.
  
  
  RESULTS
  The highest TPs (> 65%) were found for staying in the same drinking state. Higher age [hazard ratio (HR) for 1-year increase = 0.87, 95% confidence interval (CI) = 0.84-0.91], being female (HR = 0.30, 95% CI = 0.21-0.42), and a high SES (HR = 0.64, 95% CI = 0.43-0.97) were associated with a lower hazard to progress from use to RSOD. While age was associated predominantly with transitions between abstinence and alcohol use, sex was more relevant for transitions associated with RSOD and frequent RSOD.
  
  
  CONCLUSIONS
  German adolescents and young adults tend to be stable in the drinking states of abstinence, use of alcohol, risky single-occasion drinking and frequent risky single-occasion drinking. Females are less likely to transition to riskier states and more likely to transition back from frequent risky single-occasion drinking, higher age is associated with lower hazard of transitioning and participants of higher socio-economic status are less likely to transition from 'use of alcohol' to 'risky single-occasion drinking'.
authors.affiliation: Institute for Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany.|Centre for Addiction and Mental Health (CAMH), Social and Epidemiological Research Department, Toronto, ON, Canada.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Probst
authors.affiliation: Department of Automatic Control and Systems Engineering, University of Sheffield, Sheffield, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moyo
authors.affiliation: Department of Automatic Control and Systems Engineering, University of Sheffield, Sheffield, UK.
authors.forename: Robin
authors.initials: R
authors.lastname: Purshouse
authors.affiliation: Institute for Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany.|Centre for Addiction and Mental Health (CAMH), Social and Epidemiological Research Department, Toronto, ON, Canada.|Institute of Medical Science, University of Toronto, Toronto, ON, Canada.|Dalla Lana School of Public Health (DLSPH), University of Toronto, Toronto, ON, Canada.|Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Rehm
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D064829:Alcohol Abstinence / Q000523:psychology / Q000706:statistics & numerical data*; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000523:psychology; D015331:Cohort Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008390:Markov Chains; D012309:Risk-Taking; D012737:Sex Factors; D012959:Socioeconomic Factors; D013997:Time Factors; D055815:Young Adult
keywords: Adolescence; age; alcohol; alcohol use disorders; sex; socio-economic status; transition probability