Critchley JA, et al. - Since long-term variability in HbA_1c can be predictive of hospitalization or mortality, however, its importance at different average levels or trajectories was uncertain, researchers used percentiles to estimate the simultaneous impact of HbA_1c average, variability, and trajectory. Fifty-eight thousand eight hundred thirty-two patients with T2DM had HbA_1c average (mean of annual means), variability (coefficient of variation), and trajectory (annual regression slope) estimated during 2006–2009 using English primary care data. Findings suggested a strong association of HbA_1c variability with overall mortality and emergency hospitalization and not explained by average HbA_1c or hypoglycemic episodes. No correlation was found for coronary artery disease and ischemic stroke hospitalizations alone, with strongly predictive average HbA_1c. Targets will concentrate on stability as well as absolute HbA_1c level.