Efficacy and safety of a pharmacist-managed inpatient anticoagulation service for warfarin initiation and titration.
OBJECTIVE
Anticoagulation consultations provided by a pharmacist-staffed inpatient service, similar to the experience reported in outpatient anticoagulation clinics, can potentially improve anticoagulation control and outcomes. At Tan Tock Seng Hospital, a 1200-bed acute care teaching hospital in Singapore, pharmacist-managed anticoagulation clinics have been in place since 1997. Pharmacist-managed services were extended to inpatient consultations in anticoagulation management from April 2006. Our objective was to assess the effect of implementing a pharmacist-managed inpatient anticoagulation service.


METHODS
This was a single-centre cohort study. Baseline data from 1 January 2006 to 31 March 2006 were collected and compared with post-implementation data from 1 April 2006 to 31 March 2007. Patients newly started on warfarin for deep vein thrombosis, pulmonary embolism or atrial fibrillation in general medicine and surgery departments were included. The three endpoints were as follows: (i) percentage of international normalized ratios (INRs) achieving therapeutic range within 5 days, (ii) INRs more than 4 during titration and (iii) subtherapeutic INRs on discharge.


CONCLUSIONS
A total of 26 patients in the control period were compared with 144 patients who had received dosing consultations by a pharmacist during the initiation of warfarin. The provision of pharmacist consult resulted in 88% compared to 38% (P < 0·001) of INR values achieving therapeutic range within 5 days. There was a reduction in INR values of more than 4 during titration from 27% to 2% (P < 0·001), and subtherapeutic INR values on discharge without low molecular weight heparin from 15% to 0% (P < 0·001). The mean time to therapeutic INR was reduced from 6·5 to 3·9 days (P < 0·001) and mean length of stay after initiation of warfarin from 11 to 7·7 days (P = 0·004).


CONCLUSIONS
Inpatient anticoagulation care and outcomes were significantly improved by a pharmacist-managed anticoagulation service. The time to therapeutic INR was achieved appropriately and efficiently without compromising patient's safety.
Pharmacy Department, Tan Tock Seng Hospital, Jalan Tan Tock Seng, Singapore. yee_may_wong@ttsh.com.sg
Y M
YM
Wong
Y-N
YN
Quek
J C
JC
Tay
V
V
Chadachan
H K
HK
Lee
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000503:physiopathology; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006748:Hospital Departments; D006760:Hospitalization; D006784:Hospitals, Teaching; D006801:Humans; D007297:Inpatients; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010351:Patient Discharge; D010593:Pharmaceutical Services / Q000458:organization & administration; D010595:Pharmacists; D011655:Pulmonary Embolism / Q000188:drug therapy; D012017:Referral and Consultation; D012189:Retrospective Studies; D018401:Sample Size; D020246:Venous Thrombosis / Q000188:drug therapy / Q000503:physiopathology; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000078329:Workforce
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D014859:Warfarin