title: Anticoagulation control and cost of monitoring of older patients on chronic warfarin therapy in three settings in North East England.
abstract: BACKGROUND
  novel oral anticoagulants may be particularly cost-effective when INR control (TTR) with warfarin is poor or monitoring difficult.
  
  
  METHODS
  the Newcastle upon Tyne monitoring service, set in hospital or general practice and a domiciliary-based service for housebound patients.
  
  
  OBJECTIVE
  to examine anticoagulation stability and costs of monitoring.
  
  
  METHODS
  three hundred and twenty-six atrial fibrillation patients, 75 years and over, with target INR of two to three, accessing hospital (n = 100), general practice (n = 122) and domiciliary (n = 104) service.
  
  
  METHODS
  age, co-morbidities, length of warfarin treatment, medications, INR values and dose changes from January to December 2011 were recorded, and costs analysed.
  
  
  RESULTS
  home-monitored patients had taken warfarin for longer, mean 5.2 years, than hospital (3.7) or general practice (3.1) patients. Age and total number of drugs prescribed chronically were negatively related to TTR. INR measurements and dose changes were negatively associated with the duration of treatment, positively correlated with co-morbidities. The mean TTR was 78% in hospital, 71% in general practice and 68% in domiciliary monitored patients. INR was monitored more often in hospital and domiciliary groups than in general practice and more dose changes occurred in the domiciliary group than in others. Costs of warfarin and monitoring were £128 per patient per year for hospital, £126 for general practice and £222 for domiciliary patients.
  
  
  CONCLUSIONS
  further exploration of the clinical effectiveness of novel anticoagulants in dependent patients is warranted to determine to what extent trial outcomes so far achieved in a fitter elderly population are influenced by the chronic co-morbidities of old age.
authors.affiliation: Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
authors.forename: Salah
authors.initials: S
authors.lastname: Abohelaika
authors.affiliation: Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
authors.forename: Farhad
authors.initials: F
authors.lastname: Kamali
authors.affiliation: School of Mathematics and Statistics, Newcastle University, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Avery
authors.affiliation: Haematology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Brian
authors.initials: B
authors.lastname: Robinson
authors.affiliation: Haematology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kesteven
authors.affiliation: Newcastle upon Tyne Hospitals NHS Foundation Trust- Care of the Older People's Medicine, Freeman Hospital, Freeman Road, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: Hilary
authors.initials: H
authors.lastname: Wynne
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000191:economics; D001777:Blood Coagulation / Q000187:drug effects*; D015897:Comorbidity; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D016903:Drug Monitoring / Q000191:economics*; D004739:England; D005260:Female; D058006:General Practice / Q000191:economics*; D006699:Home Care Services / Q000191:economics*; D017721:Hospital Costs; D006801:Humans; D019934:International Normalized Ratio / Q000191:economics*; D008297:Male; D019338:Polypharmacy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: aged; anticoagulation costs; dependency; older people; time in therapeutic range; warfarin