Table 1 Study Characteristics

5 mg vs. 10 mg

Harrison (1997)

Canada

Inpatients & outpatients

51 patients *

(64 yrs)

%not available

INR target 2.0-3.0

1)Time to INR in range,

2) INR >3.0,

3) Time to reduction in factors II, X and protein C

Crowther (1999)

Canada

Thromboembolism unit

53 patients *

(65 yrs)

47% male

INR target 2.0-3.0. Exclusions: contraindication to warfarin or geographically inaccessible

1) Proportion with INR in range for 2 consecutive days on days 3 & 4, or 4 & 5 and INR not >3.0

Kovacs (2003)

Canada

Outpatient clinics

201 patients with DVT or PE

(55 yrs)

56% male

Exclusions: baseline INR >1.4, thrombocytopenia, <18 yrs, hospitalised, oat in previous 2 wks, high risk of bleeding

Primary Outcome:

1) Time to INR >1.9.

Secondary Outcomes:

2) INR in-range by day 5

3) VTE by day 90

4) Major bleeding by 28 days

5)INR >5.0

6)Number of INRs in 28 days

7) Death by 90 dys

Quiroz (2006)

USA

Inpatients

50 patients with DVT or PE

(50 yrs)

54% male

Exclusions: <18 yrs, not available for clinic f/up, warfarin or heparin >36 hrs, creatinine clearances of <30 ml/min, life expectancy <3 mths, high risk of bleeding

Primary Outcome:

1) Time to INR >1.9 on 2 consec. days.

Secondary Outcomes:

2) Recurrent VTE at 14 days

3) Death at 14 days

4) Major bleeding at 14 days

5) INR >5 at 14 days

5 mg vs. 2.5 mg

Ageno (2001)

Canada &Italy

Inpatients

232 patients with heart valve replacement

(64 yrs)

56% male

INR target 2.0 (range 1.5-2.6). Exclusions: baseline INR >1.3

Primary Outcome:

1) % INR >2.6

Secondary Outcomes:

2) Time to INR in range

3) % out of range

4) Vit. K/bleeding/thromboembolic events

5) Dose adjustments/mean daily dose

5 mg vs. calculated dose

Shine (2003)

USA

Inpatients

90 patients with AF, DVT, PE or other

(61 yrs)

58% male

INR target 2.0-3.0 & INR = 1.4. Exclusion; warfarin in previous 3 months

1)Time to INR in range

2) Hours in hospital

3) Number with INR 2.0-3.0

4) Factor II protein activity

5) Clinical complications

6) INR ever >4.0 or a rise of 2.0 over 2 days to >3.0

Age adjusted

Roberts (1999)

Australia

Inpatients

65 patients with AF, DVT, PE & other

(74 yrs)

70% male

INR target 2.0-3.0. Exclusions: prolonged diarrhoea, nasogastric/enteral feeds, commencing amiodarone, advanced malignancy, Vitamin K in previous 2 wks

Primary Outcome

1)Time to INR in range on 2 consecutive days or if previous day within 0.5

Secondary Outcomes

2) No. with INR >4.0 in first week

3) Dose withheld in wk1

4) No. of days with heparin

Gedge (2000)

UK

Inpatients

127 patients with - AF, DVT, PE & other

(75 yrs)

50% male

INR target 2.0-3.0. Elderly patients with standard indications.

1)Time to INR >2.0

2) Days INR in range

3)Number with INR >4.5

4) Dose prediction day 4

Genotyping

Hillman (2005)

USA

Inpatient & Outpatients

38 with DVT, PE, AF, other, postoperative orthopaedic

(70 yrs)

45% male

Exclusions: antiphospholipid antibodies, contraindication for warfarin, previous warfarin, liver disease, renal disease, non-Caucasian, <40 yrs.

Primary Outcome:

1) Feasibility of dosing model

Secondary Outcomes:

2) % time INR in-range

3)% pts with INR >4

Anderson (2007)

USA

Inpatient & Outpatients

201 with DVT, PE, AF, other, preoperative orthopaedic

(61 yrs)

53% male

INR target 2.0-3.0. Exclusions: <18 yrs, women, pregnant, lactating or child-bearing potential, rifampin within 3 wks, co-morbidities precluding standard dosing (advanced physiological age, hepatic or renal insufficiency/creatine of <25 mg/dl, terminal illness)

Primary Outcome

1) % INR out of range/patient

Secondary Outcomes:

2)time to INR >3.2 or VitK

3)%pts in range days 5 &8

4)Number of INR measures & dose adjustments

5) %pts with SAEs - INR ≥4, VitK, major bleeding, thromboembolic events, stroke, MI & death)

Caraco (2008)

Israel

Inpatients

232 with DVT, PE, AF

(58 yrs)

46% male

Exclusions: <18 yrs and baseline INR >1.4

Primary Outcomes:

1) Time to INR >2.0

2) time to stable anticoagulation (defined as 2 INR in-range 7 days apart)

Secondary Outcomes:

3) %Time INR in-range

4) Days INR out of range

5) Major bleeding/VTE events