Anticoagulation clinic cuts warfarin toxicity rate

System keeps patients from getting lost’

As medical researchers push the benefits of warfarin use, hospitals may find themselves embroiled in a new quality quandary. Unfortunately, the anticoagulant has a risk of complications and requires intense monitoring. (See related story inQI/TQM,Feb. 1997, p. 30.) Smart hospitals are keeping one step ahead of the issue by developing specialized anticoagulant centers to take some of the burden off prescribing physicians.

At the Department of Veterans Affairs Medical Center in Louisville, KY, fiscal year (FY) 1992 data showed 8.65% of patients on warfarin therapy required hospitalization due to bleeding complications. While the national incidence of warfarin toxicity is unknown, says Richard Vissing, PharmD, clinical pharmacist, "We thought this rate was too high. We wanted to know what was going on."

Using the hospital’s computer system, a team consisting of the assistant chief of staff of ambulatory care, the chief of pathology service, a clinical pharmacist, a community health nurse coordinator, and a primary care clinic physician pulled a random sample of patients and manually reviewed their charts, says Maureen Washburn, ND, RNC, CPHQ, utilization management nurse.

While they found that warfarin patients discharged from the cardiology service were given follow-up appointments with the cardiology prothrombin time (PT) clinic, there was no established protocol for following warfarin patients discharged from other services.

Problems began after surgery

"Warfarin has many uses and is given to patients with deep vein thrombosis, cardiac patients, and, for short periods of time, to orthopedic surgery patients," Washburn explains. "The difficulties came in how they were taken care of afterward." Team members found thatbothof the following had to occur for non-cardiac patients not to be "lost" in the system:

• The patient had to have some kind of follow-up appointment.

• The patient’s medication profile had to be available at the time of the clinic visit to alert the caregiver to the need for warfarin follow up.

A flowchart of the process showed a structural weakness, Washburn says. "A lot of decisions had to be made, and there was potential for a lot of rework."

First, team members developed a practitioner education program covering warfarin pharma-cology, indications, and monitoring; and the International Normalized Ratio (INR) method of reporting prothrombin times. "The INR is a more accepted standard of practice that takes into account more variabilities and is more sensitive than the PT," Vissing explains. "We do INR with every PT now."

Then team members created two additional clinics: the general medicine PT clinic for discharged inpatients and the primary care PT clinic for outpatients.

They also developed a warfarin worksheet to reduce variation in the documentation of care and to have an ongoing tracking mechanism for all patients — even those whose charts are not available at the time of their clinic visit. (See copy of warfarin worksheet, p. 55. )

After making the initial changes, the team created a flowchart for the new process and collected data on the warfarin toxicity rate. (See flowchart of updated process, p. 56.) While the rate had fallen in FY 1993 to 6.59%, team members were not satisfied, Vissing says. "It was too confusing to have three PT clinics. There were lots of overlap as to who should go to what clinic. Also, with three clinics, there wasn’t a centralized approach to making sure no one fell through the cracks," he explains.

So team members established a central anticoagulation clinic staffed by clinical pharmacists. The hospital’s policies and procedures were rewritten to allow clinical pharmacists to adjust patients’ dosages and order laboratory tests. The clinic protocol includes:

• consistent follow-up after discharge;

• therapeutic dosage adjustment;

• consultation and referral;

• patient/family education;

• practitioner education;

• monitoring and evaluation of the program.

Once a week, Vissing runs a list of all patients receiving warfarin and makes sure each has a clinic appointment, a home health appointment, or is being monitored by a private physician. This 20 minutes per week is time well spent, he says, because it ensures that everyone is monitored. The warfarin toxicity rate for FY 1996 is at 2.31%. "As the number of patients on warfarin increases as additional indications for warfarin use are published, this low rate means even more to us," he adds. (For data from 1992-1996, see bar graph, p. 57.)

The program has other benefit as well, Vissing says. Each patient who comes to the anticoagulation clinic for a PT check — a whopping 4,229 visits in FY 1996 — represents an appointment during which a clinic physician can see a patient who need medical attention.

"Warfarin patients just need to get their PT levels checked. They don’t really need to take up a physician’s time with that," Vissing explains. The pharmacists staffing the anticoagulation clinic have been able to handle 99.6% of all clinic visits without referring patients to a physician.

Vissing estimates that the cost benefit of the clinic was $75,000 in FY 1996 alone. In addition, he says, "the patients love it. They get to see the same person each time, and that familiarity has led to a great deal of trust."

Washburn concurs. Some of the clinic patients have opened up to the pharmacists about medical problems they probably would have kept to themselves had that trust not been there, she says.

[For more information, contact: Richard Vissing, clinical pharmacist, Department of Veterans Affairs Medical Center, 800 Zorn Ave., Louisville, KY 40206. Telephone: (502) 895-3401, Ext. 5904.]