The study population was different from patients receiving INR monitoring and VKA dose adjustments from their anticoagulation providers. Another study evaluated the association between center next-visit INR interval ratio (the mean number of days after a visit with an INR outside the therapeutic range, divided by the number of days after a visit with an INR within the therapeutic range) and site-level TTR.78 The results suggested that site-level TTR increased with shorter INR recall intervals. Harms and burden. No studies reported adverse effects, and the panel assumed no harms but greater burden associated with more frequent INR testing after an out-of-range INR. Other EtD criteria and considerations. There was little evidence bearing on other criteria, which, as a result, had little impact on the recommendation. Conclusions and research needs for this recommendation. The guideline panel determined that there is very low certainty evidence for net health benefit/harm associated with the INR recall interval following an out-of-range INR. Based on the limited body of available evidence, the panel was able only to suggest INR recall intervals of 4 weeks or less vs longer intervals. Most patients are adverse to frequent INR monitoring yet will return for INRs as directed by their anticoagulation provider. How much the INR is out of range should guide the choice for the INR recall interval, as well as the etiology of the out-of-range INR. For example, a recall interval between 2 and 4 weeks might be reasonable following a VKA dose adjustment for an INR of 3.3 in a patient with generally stable INR control, whereas a recall interval not exceeding a few days might be needed after temporary interruption of VKA following an INR of 8.2 in a patient who recently started taking antibiotics. The panel identified the following additional research questions. 