[Faecal occult blood test in symptomatic patients in primary care: A retrospective study in a healthcare area of Toledo]. / Sangre oculta en heces en pacientes sintomáticos en Atención Primaria: Un estudio retrospectivo en el área sanitaria de Toledo.

AIM: To review referral protocol in symptomatic patients from primary care of using 15µgHb/g faeces threshold with three consecutive samples in faecal occult blood (FOB) test. To compare test utility using current recommendations of 10µgHb/g faeces threshold and one sample. MATERIAL AND METHODS: A retrospective observational study was designed, including FOB samples of symptomatic patients from primary care. Samples were analyzed at the biochemistry laboratory in 2017. Seven hundred and fifteen patients tested positive and 925 patients negative. Exclusion criteria were secondary care request and patients under the age of 18. Descriptive analysis was performed of FOB results and clinical data about request and colonoscopy. FOB test's diagnostic utility was studied for different threshold (10 and 15µgHb/g faeces) in the same population. RESULTS: FOB positivity rate was 22.8% and cancer detection rate was 11%. However, the number of samples does not modify diagnostic precision. Negative predictive value is higher with 10µgHb/g faeces threshold. CONCLUSIONS: Correct patient selection and optimal threshold increase cancer detection rate. The protocol with 10µgHb/g faeces threshold and one sample collection for symptomatic patients from primary care improves the FOB test's purpose.

Sangre oculta en heces en pacientes sintomáticos en Atención Primaria: Un estudio retrospectivo en el área sanitaria de Toledo / Faecal occult blood test in symptomatic patients in primary care: A retrospective study in a healthcare area of Toledo

Objetivo Revisar el protocolo de solicitud de sangre oculta en heces (SOH) en pacientes sintomáticos como prueba de derivación a colonoscopia, utilizando un punto de corte de 15μg Hb/g heces en 3 muestras consecutivas y comparar su utilidad con las recomendaciones actuales de un punto de corte de 10μg Hb/g heces en una muestra. Material y métodos Estudio observacional retrospectivo centrado en las peticiones de la prueba de SOH en pacientes sintomáticos en Atención Primaria. Las muestras fueron analizadas en el servicio de laboratorio durante el año 2017. En el análisis de datos se incluyeron 715 pacientes con la prueba de SOH positiva y 925 pacientes con resultado negativo. Se realizó un análisis descriptivo de los resultados de SOH, motivo de solicitud y colonoscopia, junto con el estudio de la utilidad diagnóstica de la prueba SOH para los puntos de corte de 10 y 15μg Hb/g heces en la misma población. Resultados La tasa de positividad de la prueba fue del 22,8% y la tasa de detección de cáncer colorrectal fue del 11%. El número de muestras no modifica la precisión diagnóstica. El valor predictivo negativo es superior con el punto de corte de 10μg Hb/g heces. Conclusione La selección correcta de pacientes y del punto de corte óptimo aumentan la tasa de detección de cáncer colorrectal. El cambio de protocolo de 10μg Hb/g heces y la recogida de una muestra para pacientes sintomáticos desde Atención Primaria mejoran la utilidad de la prueba SOH (AU)

Aim To review referral protocol in symptomatic patients from primary care of using 15μgHb/g faeces threshold with three consecutive samples in faecal occult blood (FOB) test. To compare test utility using current recommendations of 10μgHb/g faeces threshold and one sample. Material and methods A retrospective observational study was designed, including FOB samples of symptomatic patients from primary care. Samples were analyzed at the biochemistry laboratory in 2017. Seven hundred and fifteen patients tested positive and 925 patients negative. Exclusion criteria were secondary care request and patients under the age of 18. Descriptive analysis was performed of FOB results and clinical data about request and colonoscopy. FOB test's diagnostic utility was studied for different threshold (10 and 15μgHb/g faeces) in the same population. Results FOB positivity rate was 22.8% and cancer detection rate was 11%. However, the number of samples does not modify diagnostic precision. Negative predictive value is higher with 10μgHb/g faeces threshold. Conclusions Correct patient selection and optimal threshold increase cancer detection rate. The protocol with 10μgHb/g faeces threshold and one sample collection for symptomatic patients from primary care improves the FOB test's purpose (AU)