© 2018 The Author(s). This Article contains errors in Reference 25, which is incorrectly given as: 'O'Sullivan, J. W. et al. Overtesting and undertesting in primary care: a systematic review and meta-analysis BMJ Open 2018;8:e018557. https://doi.org/10.1136/bmjopen-2017-0185578557.' The correct reference is listed below as ref. 1.