Predicting prolonged duration of fever in children: a cohort study in primary care.

Background Fever in children in primary care is commonly caused by benign infections, but often worries parents. Information about the duration of fever and its predictors may help in reassuring parents, leading to diminished consultation of health care. Aim To determine which signs and symptoms predict a prolonged duration of fever in febrile children in primary care and evaluate whether C-reactive protein (CRP) measurement has an additive predictive value for these symptoms. Design and setting A prospective cohort study at a GPs’ cooperative (GPC) out-of-hours service. Method Children (aged 3 months to 6 years) presenting with fever as stated by the parents were included. Exclusion criteria were no communication in Dutch possible, previous enrolment in the study within 2 weeks, referral to the hospital directly after visiting the GPC, or no informed consent. The main outcome measure was prolonged duration of fever (>3 days) after initial contact. Results Four-hundred and eighty children were analysed, and the overall risk of prolonged duration was 13% (63/480). Multivariate analysis combined model of patient history and physical examination showed that ‘sore throat’ (OR 2.8; 95% CI = 1.30 to 6.01) and ‘lymph nodes palpable’ (OR 1.87; 95% CI = 1.01 to 3.49) are predictive for prolonged duration of fever. The discriminative value of the model was low (AUC 0.64). CRP had no additive value in the prediction of prolonged duration of fever (OR 1.00; 95% CI = 0.99 to 1.01). Conclusion The derived prediction model indicates that only a few signs and symptoms are related to prolonged duration of fever. CRP has no additional value in this model. Overall, because the discriminative value of the model was low, the duration of fever cannot be accurately predicted.