Reference:
Campbell JL, Britten N, Green C, Holt TA, Lattimer V, Richards SH, Richards DA, Salisbury C, Taylor RS, Fletcher E. The effectiveness and cost-effectiveness of telephone triage of patients requesting same day consultations in general practice: study protocol for a cluster randomised controlled trial comparing nurse-led and GP-led management systems (ESTEEM). Trials 2013;14: 4.