Michael A Kohn1,2, Frederikus A Klok3, Nick van Es4. 1. Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA. 2. Department of Emergency Medicine, Mills-Peninsula Medical Center, Burlingame, CA. 3. Department of Medicine-Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands. 4. Department of Vascular Medicine, Academic Medical Center (NvE), Amsterdam, the Netherlands.
Abstract
OBJECTIVE: The objective was to estimate D-dimer interval likelihood ratios (iLRs) for diagnosing pulmonary embolism (PE). METHODS: The authors used pooled patient-level data from five PE diagnostic management studies to estimate iLRs for the eight D-dimer intervals with boundaries 250, 500, 750, 1,000, 1,500, 2,500, and 5,000 ng/mL. Logistic regression was used to fit the data so that an interval increase corresponds to increasing the likelihood ratio by a constant factor. RESULTS: The iLR for the D-dimer interval 1,000-1,499 ng/mL was essentially 1.0 (0.98 with 95% confidence interval [CI] = 0.82-1.18). In the logistic regression model, the constant between-interval factor was 2.0 (95% CI = 1.9-2.1). Using these iLR estimates, if the pre-D-dimer probability of PE is 15%, only a D-dimer less than 500 ng/mL will result in a posttest probability below 3%; if the pretest probability is 5%, the threshold for a "negative" D-dimer is 1,000 ng/mL. CONCLUSIONS: A decision strategy based on these approximate iLRs agrees with several published strategies.
OBJECTIVE: The objective was to estimate D-dimer interval likelihood ratios (iLRs) for diagnosing pulmonary embolism (PE). METHODS: The authors used pooled patient-level data from five PE diagnostic management studies to estimate iLRs for the eight D-dimer intervals with boundaries 250, 500, 750, 1,000, 1,500, 2,500, and 5,000 ng/mL. Logistic regression was used to fit the data so that an interval increase corresponds to increasing the likelihood ratio by a constant factor. RESULTS: The iLR for the D-dimer interval 1,000-1,499 ng/mL was essentially 1.0 (0.98 with 95% confidence interval [CI] = 0.82-1.18). In the logistic regression model, the constant between-interval factor was 2.0 (95% CI = 1.9-2.1). Using these iLR estimates, if the pre-D-dimer probability of PE is 15%, only a D-dimer less than 500 ng/mL will result in a posttest probability below 3%; if the pretest probability is 5%, the threshold for a "negative" D-dimer is 1,000 ng/mL. CONCLUSIONS: A decision strategy based on these approximate iLRs agrees with several published strategies.
Authors: Hanny Al-Samkari; Rachel P Rosovsky; Rebecca S Karp Leaf; David B Smith; Katayoon Goodarzi; Annemarie E Fogerty; David B Sykes; David J Kuter Journal: Blood Adv Date: 2020-01-14
Authors: Kenneth A Michelson; Mark I Neuman; Christopher M Pruitt; Sanyukta Desai; Marie E Wang; Adrienne G DePorre; Rianna C Leazer; Laura F Sartori; Richard D Marble; Sahar N Rooholamini; Christopher Woll; Fran Balamuth; Paul L Aronson Journal: Arch Dis Child Date: 2020-08-20 Impact factor: 4.920