Both primary and secondary aims were achieved for this quality improvement project. The primary aim of 85% protocol use was exceeded with actual protocol use of 97.3%. The secondary aim of a 10% improvement in TTR was also exceeded with improvement in primary TTR of 15.7%, and improvement in the post-hoc analysis TTR of 18.7%. Both the primary and post-hoc pre-intervention and post-intervention differences were clinically and statistically significant.
Interpretation
Outcomes. The results of this project confirmed that consistent use of a warfarin dosing protocol can significantly improve TTR of INR values in primary care. This is consistent with other studies in the current literature as previously discussed in this report. The results also demonstrated that consistent use of a warfarin dosing protocol by all providers at RMA was a needed and successful practice change. This practice change is also clinically significant as it should improve patient outcomes for this rural primary care practice because increased TTR decreases warfarin-related morbidity and mortality (Kim, et al., 2009; Lip, et al., 2015; Rose, 2012; Van Spall, et al., 2012).
Observed difference in groups. The number of INR values in the post-intervention group was 101 less than the pre-intervention group. There are several possible explanations for this. Patients return for repeat INR testing less frequently when their INR is within the
and therefore fewer INR values to collect. Approximately five patients taking warfarin in 2017 had passed away prior to project implementation. The cause of death for these patients was not collected for the purposes of this project. Some of the patients taking warfarin in 2017 were switched to direct oral anticoagulant medications prior to or during protocol implementation in 2018. The exact number of patients is not known but was estimated to be around 10 total patients.
Deviation from protocol. The protocol was used in 97.3% of total opportunities during project implementation; this equates to the protocol not being used in only four of 146
opportunities. A review of the EMR and “Warfarin Dosing” forms was conducted by the project leader for possible explanations for not using the protocol. The protocol was not used in three of these occurrences because the patient had missed scheduled doses prior to their INR test. For one of these three, the patient had not taken his warfarin for five days prior due to having a colonoscopy the week before the office visit, so the provider restarted his prior dose and did not use the protocol to adjust the warfarin dose. For another one of these three, the patient forgot to take the warfarin dose the night before and had recently been discharged from the hospital. That patient’s dose was adjusted to match what they had been taking during their hospital stay and not based on the protocol. For the last one of these three, the patient had intentionally not taken several doses of warfarin because he was unsure of taking it when he started another new medication. The patient’s warfarin was restarted at the intended dose instead of adjusting it based on the protocol. For the remaining one occurrence, the patient’s INR value was slightly low, and the dose was not adjusted because the patient received a prescription for an antibiotic the day of the office visit, leading to a potential drug interaction that could cause a
Out-of-range values. The post-intervention post-hoc analysis TTR using the expanded therapeutic range was 81.5%. This indicates that 18.5% of the INR values were not within the expanded therapeutic range. A review of the EMR and “Warfarin Dosing” forms was conducted by the project leader for possible explanations of these out-of-range INR values. There were 146 total INR values with 119 values within the expanded therapeutic range and 27 out-of-range values. Of these 27 out-of-range values, 15 were above the therapeutic range and 12 were below. Three were from the same patient that was on hemodialysis, six were from patients who had been on antibiotics or started new medications since the last INR test, eight were from patients taking the warfarin incorrectly or had missed recent warfarin doses, and ten were unable to be explained by chart review. All three of the INR values for the patient on hemodialysis were low. Dialysis can alter metabolism of warfarin, leading to a subtherapeutic INR value despite use of the protocol for dose adjustments (Abe, Maruyama, Suzuki, Okada, & Soma, 2012). The protocol did not include dose considerations specifically for patients on
hemodialysis. Multiple medications, especially antibiotics, can interact with warfarin and alter INR levels which could potentially explain the six INR values that were out-of-range for patients who had received antibiotics or new medications since the last INR test (Bungard, Yakiwchuk, Foisy, & Brocklebank, 2011). The protocol did not include dose considerations for patients starting new medications or on antibiotics.
Barriers
Several barriers existed for this project. The largest barrier related to stakeholder buy-in and engagement. Not all stakeholders perceived this project as important or necessary for their practice and were skeptical of the evidence. Providing stakeholders with pre-implementation percent TTR data did improve buy-in and a desire for change. This gave them tangible,
warfarin therapy and use of a warfarin dosing protocol was not a part of the existing core
meaningful use measures with the Centers for Medicare and Medicaid Services or the practice’s Accountable Care Organization quality measures, the providers did not feel this was a priority for practice improvement. They had numerous other measures they were focused on at the time of the project implementation. The project leader attempted to overcome this major barrier by presenting them with objective data and using communication techniques that reached them, based on DOI theory. This included educating them on the literature review findings, current EBP guidelines, and professional organization recommendations, which support use of a warfarin dosing protocol. It seemed that the providers were willing to use the protocol for this project temporarily and wished to decide afterward as to whether they would sustain this practice change based on the post-implementation data and ease of use. Remaining flexible and positive as a project leader and respecting all stakeholders’ concerns and suggestions was important in engaging them. Adapting the workflow using stakeholder input created a sense of ownership for the project since their ideas shaped the final product and hopefully improved the likelihood of sustainability of the practice change following project completion.
Other barriers included the perceived time commitment required to use the protocol and the perceived threat to provider autonomy for warfarin dose adjustments. The providers’ initial response to the dose adjustment calculations and documentation workflow that was originally presented to them was perceived as too time consuming and complicated when they compared it to their current practice. Workflow adaptations were made using their input to decrease
perceived complexity and time concerns. It was also made clear to providers that their experience in dosing warfarin remained important and that the protocol was not intended to replace or override their clinical judgment. Instead, it was presented as a tool to support them and
create consistency of care among all providers at the practice. The providers could override the protocol if there was a specific reason to do so for a specific patient based on their clinical judgment, which was not questioned by the project team.
Limitations
The 13-week duration of the project may be insufficient to gauge long-term results. Retrospective historical data were collected for the pre-intervention group and characteristics of the patients within that group were not compared to those within the post-intervention group to determine similarities and differences between groups. Complex patients whose INR values were more likely to fall outside of the therapeutic range may have had more INR values within the duration of the project because of the need for more frequent INR testing. Despite provider instructions, some patients may not have presented for an INR test during the 13-week project implementation. It is possible that these patients with low adherence to prescribed treatment would be more likely to have INR values outside of the therapeutic range and were potentially not captured during the duration of this project. These potential limitations were difficult to minimize and there were no specific changes identified or conducted to adjust for them.
The protocol itself had limitations. It did not include recommendations for patients who had missed doses, had recently taken or were currently taking antibiotics, or who were on hemodialysis. There are practice tools available to assist providers with medical decision
making in these cases, but they were not included with this protocol or in this project. Some may argue that these perceived protocol limitations could be considered a strength as provider
experience and individualized patient care are important to add to the baseline of EBP guidelines.
CHAPTER 5: CONCLUSIONS