Authors' contributions
The study design was developed by HW with assistance from NDB, JHW, SM, OK, KM and JH. HW, JHW, SM, OK and KM instructed the GP practices according to their study group and took part in data analysis. JH and BW were the responsible statisticians. Under their supervision JHW analyzed and interpreted the data concerning the primary outcome antibiotic prescription rate, KM analyzed and interpreted the data regarding the diagnostic tests (scores and RADT), and OK analyzed and interpreted the data reported in the diaries. HW, HK and NDB gave support in the analysis and interpretation of data. HW wrote the manuscript with support and contributions by HK, NDB and JH. All authors read and approved the final manuscript.