Hospital admissions often mean patients have to stay in bed for an extended period of time which can result in clots. In extreme cases blood clots can result in heart attack or stroke leading to death.
Doctors juggle multiple factors when deciding whether to give a patient blood thinners, to prevent clots, such as the patient's age, weight and medical history.
Previously, decisions around avoiding blood clots were at the discretion of each doctor.
"I guess it decreases that random nature, I think," Dr Pohl said. "What we've implemented is a standardised process."
The campaign introduced a checklist, which went through 20 drafts, that staff have to go through with patients before they are discharged.
Around 85 per cent of patients now receive a brochure outlining the signs of a blood clot before they are discharged.
Manager for Quality and Improvement Directorate at Northland District Health Board, Christina Rood, said a team of eight had been meeting fortnightly to work on the new strategy.
"I'm not sure that any other hospital [in New Zealand] have got it like a whole package like we have," Ms Rood said.
Ms Rood follows up with each patient for three months after hospital admission to see whether they had a blood clot.
Often patients who do have blood clots after hospital admission are treated at their local GP, meaning the doctor who treated them in hospital did not know anything was wrong.
"Before this process, part of the reason some of the clinicians weren't engaged in it because we often didn't see the instances," Dr Pohl said.
The improvement project was implemented in full in September at Whangarei Hospital, with Kaitaia, Dargaville and Bay of Island Hospitals to follow soon.