Pitfalls in acute febrile illness diagnosis: interobserver agreement of signs and symptoms during a dengue outbreak.

To compare and evaluate interobserver (nurses and physicians) agreement for dengue clinical signs and symptoms, including the WHO diagnostic algorithm.Agreement of clinical history defines the capacity of the examiner to measure a given clinical parameter in a reproducible and consistent manner, which is prerequisite for diagnosis validity. Nurses play a major role in the triage and care of dengue patients in many countries.This is a sub-study on interobserver agreement performed as part of a cross-sectional diagnostic accuracy study for acute febrile illness (AFI) using the checklist STARD.A previously validated semi-structured sign and symptom standardized questionnaire for AFI was independently administered to 374 patients by physician and nurse pairs. The interobserver agreement was estimated using Kappa statistics.For a set of 27 signs and symptoms, we found six interobserver discrepancies (examiner detected red eyes, lethargy, exanthema, dyspnea, bleeding and myalgia) as identified by regular and moderate Kappa indexes. Four signs (patient observed red eyes, cough, diarrhea and vomiting) and one symptom (earache) had near perfect agreement. Most signs and symptoms showed substantial agreement. The WHO (2009) clinical criteria comprise a group of symptoms known as "pains and aches". Interobserver agreement for abdominal pain, retroorbital pain and arthralgia exceed that found for headache and myalgia.During a dengue outbreak, the interobserver agreement for most of the signs and symptoms used to assess AFI was substantial.This result suggests good potential applicability of the tool by health professionals following training. A well-trained health-professional is qualified to apply the standardized questionnaire to evaluate suspected dengue cases during outbreaks.