title: Chronic illness and multimorbidity among problem drug users: a comparative cross sectional pilot study in primary care.
abstract: BACKGROUND
  Although multimorbidity has important implications for patient care in general practice, limited research has examined chronic illness and health service utilisation among problem drug users. This study aimed to determine chronic illness prevalence and health service utilisation among problem drug users attending primary care for methadone treatment, to compare these rates with matched 'controls' and to develop and pilot test a valid study instrument.
  
  
  METHODS
  A cross-sectional study of patients attending three large urban general practices in Dublin, Ireland for methadone treatment was conducted, and this sample was compared with a control group matched by practice, age, gender and General Medical Services (GMS) status.
  
  
  RESULTS
  Data were collected on 114 patients. Fifty-seven patients were on methadone treatment, of whom 52(91%) had at least one chronic illness (other then substance use) and 39(68%) were prescribed at least one regular medication. Frequent utilisation of primary care services and secondary care services in the previous six months was observed among patients on methadone treatment and controls, although the former had significantly higher chronic illness prevalence and primary care contact rates. The study instrument facilitated data collection that was feasible and with minimal inter-observer variation.
  
  
  CONCLUSIONS
  Multimorbidity is common among problem drug users attending general practice for methadone treatment. Primary care may therefore have an important role in primary and secondary prevention of chronic illnesses among this population. This study offers a feasible study instrument for further work on this issue. (238 words).
authors.affiliation: UCD School of Medicine and Medical Science, Coombe Healthcare Centre, Dublin, Ireland. walter.cullen@ucd.ie
authors.forename: Walter
authors.initials: W
authors.lastname: Cullen
authors.forename: Sarah
authors.initials: S
authors.lastname: O'Brien
authors.forename: Austin
authors.initials: A
authors.lastname: O'Carroll
authors.forename: Fergus D
authors.initials: FD
authors.lastname: O'Kelly
authors.forename: Gerard
authors.initials: G
authors.lastname: Bury
mesh_terms: D000328:Adult; D002908:Chronic Disease / Q000453:epidemiology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D055030:Drug Users / Q000706:statistics & numerical data*; D005260:Female; D040261:Harm Reduction; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008691:Methadone / Q000627:therapeutic use; D009294:Narcotics / Q000627:therapeutic use; D010865:Pilot Projects; D011204:Poverty Areas; D011320:Primary Health Care / Q000379:methods*; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology* / Q000534:rehabilitation
chemical_list: D009294:Narcotics; D008691:Methadone