Improving the safety and efficacy of anticoagulation therapy

ISRCTN	ISRCTN64826232
DOI	https://doi.org/10.1186/ISRCTN64826232
Protocol serial number	8579
Sponsor	Newcastle upon Tyne Hospitals NHS Foundation Trust (UK)
Funder	National Institute for Health Research (NIHR) (UK) - Research for Patient Benefit (RfPB) programme

Submission date: 21/10/2010
Registration date: 21/10/2010
Last edited: 30/09/2016

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Haematological Disorders

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Hilary Wynne
Scientific

Newcastle upon Tyne Hospitals NHS Foundation Trust
Queen Victoria Road
Newcastle Upon Tyne
NE1 4LP
United Kingdom

Study information

Primary study design	Observational
Study design	Single-centre non-randomised observational screening cohort study
Secondary study design	Cohort study
Study type	Participant information sheet
Scientific title	Improving the safety and efficacy of anticoagulation therapy for thromboembolic disease through vitamin K: a single centre randomised controlled trial
Study objectives	To investigate whether daily supplementation with vitamin K improves the stability of anticoagulation control in patients on chronic therapy with warfarin.
Ethics approval(s)	Sunderland Research Ethics Committee, 08/06/2009, ref: 09/H0904/25
Health condition(s) or problem(s) studied	Topic: Blood; Subtopic: Blood (all Subtopics); Disease: Non-malignant haematology
Intervention	Randomised (blinded) to vitamin K/placebo 150 µg orally once daily for 6 months. Follow-up at 1, 2, 4, 8, 12, 16, 20, and 24 weeks post initial dose.
Intervention type	Supplement
Primary outcome measure(s)	Percent time within target INR (calculated by the method of interpolation) for the study period, measured at baseline and weeks 1, 2, 4, 8, 12, 16, 20 and 24 weeks.
Key secondary outcome measure(s)	1. Clinical events of major (defined as bleeding that led to loss of 2 units of blood over a 7 day period 2. Days attending anticoagulation clinic to monitor and achieve target International Normalised Ratio (INR) 3. Markers of lack of efficacy including recurrent thrombosis 4. The number of warfarin dose changes 5. Quality of life questionnaires recorded at baseline and repeated at the end of the study
Completion date	01/01/2013

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	All
Target sample size at registration	180
Key inclusion criteria	1. Long term warfarin therapy 2. Aged greater than or equal to 18 years 3. Male and female
Key exclusion criteria	1. Abnormal hepatic or renal function 2. Impairment of cognitive function
Date of first enrolment	01/07/2010
Date of final enrolment	01/01/2013

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

Newcastle upon Tyne Hospitals NHS Foundation Trust

Newcastle Upon Tyne
NE1 4LP
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
HRA research summary			28/06/2023	No	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

30/09/2016: No publications found, verifying study status with principal investigator