RESUMEN
Introducción Las bacteriemias por microorganismos anaerobios son poco frecuentes, no existiendo consenso sobre su predictibilidad clínica y la utilidad rutinaria de los medios de cultivo para anaerobios. El objetivo del estudio es crear y validar un modelo predictivo de bacteriemia por anaerobios. Métodos El modelo predictivo se realizó con 984 bacteriemias (45 anaerobios estrictos) durante 198586 y 199697. La validación durante 200506 con 320 bacteriemias. Resultados Los factores predictores de bacteriemia por anaerobios calculados en el análisis multivariante para la creación de un modelo estratificado con puntuaciones de 013 puntos (p) fueron: origen desconocido (OR: 3,46; IC 95%: 1,1310,54) 3 p; origen abdominal y cutáneo (OR: 14,85; IC 95%: 6,3734,62) 6 p; hipotensión (OR: 1,99; IC 95%: 0,984,04) 2 p; ausencia de manipulaciones vasculares (OR: 2,62; IC 95%: 1,046,60) 2 p y edad >60 años (OR: 3,21; IC 95%: 1,198,67) 3 p. Con >7 p el modelo tiene S:77,8%, E:78,3%, VPP: 14,7% y un VPN del 98,6%, área bajo curva ROC=0,84 (EE=0,011). IC 95%: 0,820,86 con prevalencia de bacteriemia por anaerobios estimada 4,6%. La validación del modelo se realizó con 320 bacteremias (55 de ellas por anaerobios estrictos). El 83,6% (IC 95%: 71,1992,23) de las bacteriemias por anaerobios tienen >7 p, y el 72,7% tienen 9 p o más. El 26,4% (IC 95%: 21,232,15) de las bacteriemias por aerobios y aerobios-anaerobios facultativos tienen >7 p, y solo el 11,7% tienen 9 p o más.Área bajo curva ROC=0,82 (EE=0,02). IC 95%: 0,780,86. Prevalencia estimada 2%.ConclusionesEl origen abdominal y cutáneo OR 14,85; origen desconocido OR 3,46; hipotensión OR 1,99; ausencia de manipulaciones vasculares OR 2,62 y edad >60 años OR 3,21 permiten crear un modelo clínico predictivo de bacteriemia por anaerobios con alta S y E. Por su baja prevalencia la importancia del modelo radica en su altísimo valor predictivo negativo (AU)
Introduction Anaerobic bacteremias are uncommon. There is no agreement on their clinical predictability and the usefulness of anaerobic blood cultures. The objective of this study was to develop and validate a model for the prediction of anaerobic bacteremias. Method The developing model was created with 984 bacteremias (45 anaerobic bacteremias) during 19851986 and 19961997. The validation model was made with 320 bacteremias during 20052006.ResultsIndependent multivariate predictors of true anaerobic bacteremia were used to develop a model stratifying patients with scores of 0 to 13 points(p), which were: unknown focus OR 3.46 (CI: 1.1310.54) 3 p; abdominal and skin focus OR 14.85 (CI: 6.3734.62) 6p; hypotension OR 1.99 (CI: 0.984.04) 2p; absence of vascular manipulations OR 2.62 (CI: 1.046.60) 2p and age over 60 years OR 3.21 (CI: 1.198.67) 3p. In the derivation sets group with more than 7p the model had Sensitivity: 77.8%, Specificity: 78.3%, PPV:14.7%, and a NPV of 98.6%. The area under curve was ROC=0.84 (SE=0.011), 95% CI: 0.820.86 (..) (AU)
Asunto(s)
Bacteriemia/sangre , Bacteriemia/microbiología , Bacterias Anaerobias , Técnicas Bacteriológicas , Modelos Teóricos , Valor Predictivo de las Pruebas , Bacteriemia/diagnóstico , Estudios ProspectivosRESUMEN
INTRODUCTION: Anaerobic bacteremias are uncommon. There is no agreement on their clinical predictability and the usefulness of anaerobic blood cultures. The objective of this study was to develop and validate a model for the prediction of anaerobic bacteremias. METHOD: The developing model was created with 984 bacteremias (45 anaerobic bacteremias) during 1985-1986 and 1996-1997. The validation model was made with 320 bacteremias during 2005-2006. RESULTS: Independent multivariate predictors of true anaerobic bacteremia were used to develop a model stratifying patients with scores of 0 to 13 points(p), which were: unknown focus OR 3.46 (CI: 1.13-10.54) 3 p; abdominal and skin focus OR 14.85 (CI: 6.37-34.62) 6p; hypotension OR 1.99 (CI: 0.98-4.04) 2p; absence of vascular manipulations OR 2.62 (CI: 1.04-6.60) 2p and age over 60 years OR 3.21 (CI: 1.19-8.67) 3p. In the derivation sets group with more than 7p the model had Sensitivity: 77.8%, Specificity: 78.3%, PPV:14.7%, and a NPV of 98.6%. The area under curve was ROC=0.84 (SE=0.011), 95% CI: 0.82-0.86 with an anaerobic bacteremia prevalence of 4.6%. The validation set was studied analysing 320 bacteremias. Of these, 83.6% (95% CI: 71.19%-92.23%) of anaerobic bacteremias had more than 7 points, and 72.7% had more than 9 points. There was 26.4% (95% CI: 21.2%-32.15%) aerobic and facultative anaerobic bacteremias with more than 7 points, and only the 11.7% with 9 or more points. The area under the curve was, ROC=0.82 (SE=0.02), 95% CI:0.78-0.86, and estimated prevalence, 2%. CONCLUSIONS: Abdominal and skin focus OR 14,85; unknown focus OR 3,46; hypotension OR 1,99; absence of vascular manipulations OR 2,62 and age over 60 years enable us to make a predictive clinical model of probability of anaerobic bacteremia with a high sensitivity and specificity. The model particularly has a significant predictive negative value due to the low prevalence of anaerobic bacteremia.
Asunto(s)
Bacteriemia/sangre , Bacteriemia/microbiología , Bacterias Anaerobias , Adulto , Bacteriemia/diagnóstico , Técnicas Bacteriológicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Valor Predictivo de las Pruebas , Estudios ProspectivosRESUMEN
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