RESUMO
OBJECTIVE: To assess the effect of a targeted age-specific computerized alert to reduce D-dimer testing in elderly patients. STUDY DESIGN: A single-crossover cluster randomized trial of computerized alerts during physician order entry involving 8 ambulatory care clinics in a group-model integrated care delivery system. METHODS: The rate of completed D-dimer tests per 1000 patient visits, ratio of completed venous ultrasonography to completed D-dimer tests, and rate of completed venous ultrasonography per 1000 patient visits. RESULTS: The rate of completed D-dimer tests per 1000 visits among patients 65 years and older in intervention clinics decreased from 5.02 to 1.52 (95% confidence interval [CI], -4.20 to -2.80; P <.001), which persisted throughout the study period. The rate of completed D-dimer tests per 1000 visits among patients 65 years and older in control clinics decreased from 3.14 to 2.11 (95% CI, -1.66 to -0.04; P <.001 for interaction). After activation of the alert in control clinics, the rate of completed D-dimer tests per 1000 visits among patients 65 years and older decreased from 2.11 to 0.81 (95% Cl, -1.79 to -0.80; P <.001). After activation of the alert in each clinic group, the ratios of completed venous ultrasonography to completed D-dimer tests increased from 1.17 to 4.05 (95% CI, 2.52-3.22) and from 2.25 to 7.29 (95% CI, 3.74-6.35) in intervention clinics and control clinics, respectively (P <.001 for both). CONCLUSION: An electronic age-specific alert targeted to a specific condition reduced D-dimer testing in this elderly population of outpatients and demonstrated a persistent effect.