Mycoplasma pneumoniae detection causes excess antibiotic use in Norwegian general practice: a retrospective case-control study.

BACKGROUND: The 2011 Mycoplasma pneumoniae epidemic in Norway resulted in many GP consultations and significantly increased the prescription of macrolide antibiotics. AIM: To investigate the signs, symptoms, course, and prescription patterns of antibiotics in patients positive for M. pneumoniae compared with patients negative for M. pneumoniae. DESIGN AND SETTING: A retrospective case-control study using questionnaires collected from GPs in a county in Norway. A total of 212 M. pneumoniae positive and 202 control patients were included. METHOD: Descriptive statistics and logistic regression analyses were performed on the reported findings. RESULTS: Forty-eight per cent of patients positive for M. pneumoniae received an antibiotic at first consultation. Another 45% in the same group received antibiotics after the polymerase chain reaction (PCR) result was known, although these patients were not clinically different from all other patients not receiving an antibiotic at first consultation. Logistic regression analysis to evaluate independent predictors for prescription of antibiotics at first consultation showed that the following factors were significantly associated: elevated C-reactive protein (CRP) level, temperature >38.0°C, pathological findings on pulmonary auscultation, and impaired general condition. Elevated CRP level, younger age, temperature >38.0°C, short duration of symptoms, and absence of rhinitis were found to be positive predictors for M. pneumoniae infection. CONCLUSION: A positive PCR test for M. pneumoniae tends to trigger an antibiotic prescription, irrespective of the severity of the patient's condition at first consultation. New guidelines for treatment and possibly PCR testing should be established.