1 Syd Stewart and Claire Alexander November 2003 Patient Compliance and Benchmarking

2 Outline Review of Dawn AC Benchmarking Service Investigation of Performance Differences between centres

3 Review of Dawn AC Benchmarking Service Established in 1998 Runs twice a year, starting eleventh run Nov 2003 Over 70 centres from UK, US and Australia Approximately patients Over INR records Number of centres

4 What is Benchmarking? “ A process for rigorously measuring your performance versus the best-in-the-class and for using the analysis to meet and surpass the best-in-the-class.”

5 Performance variation between centres Average % Time in Range (TIR) performance varies amongst centres. For the 2.5 target range and patients in 22+ week of treatment, the % TIR varies from 57% to 77%. What are the reasons for this variation?

6 Impact of 15% variation in TIR 2000 patients 15 % difference in TIR 300 patient years out of range Risk of stroke is 5%, reduced to 1.5% with Warfarin For 300 patient years this is equivalent to 10 strokes

7 Investigation of Performance Differences -Patient mix (age, gender, reason for treatment) -Manual Intervention practices -INR measurement systems -Patient compliance / education

8 Impact of Patient Age on average TIR Patient age appears to affect the average TIR performance. Patients that are younger than 60 and older than 85 perform more poorly than those between 60 and 85 years old.

9 Impact of Patient Gender on average TIR The gender of the patient appears to affect the average TIR performance. Female patients appear to perform more poorly than male patients.

10 Impact of AC Reason on average TIR Group 1: AF Arrhythmia Group 2: DVT PE Group 3: Heart Valve replacement Group 4: CVA TIA Group 5: All other The reason that the patient is taking anticoagulation treatment appears to affect the average TIR performance. Patients with DVT/PE appear to perform more poorly than others.

11 Standardisation Chart The standardisation process transforms the % TIR to a standardised control rating, with a target value of 100. If all centres cross the 100 line then there is no statistically significant difference between the centres.

12 Manual intervention rate All centres are using the same Dawn software but some centres rarely override the calculated dose and some override frequently. INR measurement systems The quality and reliability of the INR measurement may impact overall performance. Patient compliance / adherence centres vary in their procedures for following up DNAs, their focus on patient communication and their patient education programs. Other factors that could influence performance

13 Impact of intervention on INRs in range Manual intervention (override) appears to impact % INRs in range. Generally patients whose computer recommended dose is overridden more often show worse performance.

14 Correlation between override and performance Although dose intervention appears to impact patient performance the correlation is not very strong (-0.3) and there are many centres that do not fit the pattern. Other factors must also play a part.

15 Plot of Daily INR - “Good” site

16 Plot of Daily INR - “Poor” site

17 INR Measurement Quality Control What can the variation in the average daily INR reveal about centre performance? We expect that the average daily INR should not vary too much from the target. This centre shows some periods where the average daily INR drops low or jumps high.

18 INR Measurement Quality Control This centre’s steady improvement is interrupted by a short period where the daily % INRs in range dropped off suddenly. This period coincides with the period of abnormally high daily average INRs.

19 INR Measurement Quality Control Plotting both measurements together clearly shows that the drop in % INRs in range coincides with the period of abnormally high INRs. DAWN Performance Manager available from:

20 In a study for the Italian Federation of Anticoagulation Clinics, G. Palareti found: Patient Compliance / Adherence The following characteristics are more frequent in unstable pts: - Unawareness of the reasons for OAT - Poor understanding of OAT mechanisms - Admitted compliance problems - In employment

21 Schooling Living Alone Warfarin or acenocoumarol Diet habits Alcohol consumption Comorbid conditions Associated drugs Blood cell counts Liver/renal function Palareti study showed that the following factors did not play a significant role in patient performance Patient Compliance / Adherence

22 P<0.001 P< P<0.001 Palareti found that the study itself led to an improvement in some aspects of anticoagulation control in unstable patients. Patient Compliance / Adherence Unstable patients: changes in anticoagulation quality 4 months after enrollment

23 Is it all down to Patient Education? Patient Compliance / Adherence

24 Patient Compliance / Adherence Palareti also found that unstable pts spend more time in a condition of overanticoagulation (below range). Dawn AC benchmarking results support this.

25 Dose INR Patient Compliance / Adherence Could patient compliance / adherence explain some abrupt jumps in INR?

26 Dose INR Patient Compliance / Adherence Could patient compliance / adherence explain some abrupt jumps in INR?

27 Patient Compliance / Adherence How can we model the effect of non-compliance on INR behaviour? Demonstration

28 Summary New Supplementary Report in Next Benchmarking run -Patient Mix standardisation -INR Time Series Analysis Patient Compliance / Education – Highly Significant? Benchmarking Event monitoring?

29 End of presentation