Lattimer 1998.

Methods	Randomised trial
Participants	10134 patients (total group), all ages, 48% male 6 nurses 55 doctors
Interventions	Intervention: nurse call management during out‐of‐hours Control: GP call management during out‐of‐hours Detailed description of the intervention: Compared 2 groups answering incoming phone calls for patients during out‐of‐hours Nurse telephone consultation: In the intervention arm of the trial, all calls were passed straight to the nurse, except in the case of immediate referral to the ambulance service by the receptionist. The nurse then undertook a systematic assessment of the caller's problem and recommended an appropriate course of action. The nurse was aided by TAS (telephone advice system), a computer‐based primary care call management system. Triage nurses were able to complete calls without onward referral. Call management options for nurses included: Telephone advice: on home management of the problem to see the patient’s own GP the next day to attend the Accident and Emergency Department Referral of the patient to the GP on duty: inviting the patient to attend the primary care centre advising the caller that the GP would contact them by telephone contacting the 999 ambulance service plus referral to the GP on duty referring to another agency (e.g. on call Community Psychiatric Nurse) plus referring to the GP on duty At the time of the study, triage nurses were seen to be acting as ‘competent agents’ of the GP. They had personal professional responsibility to ensure that they had been adequately prepared for the role and were accountable for their own actions. The GP could delegate care, but not accountability for that care. Doctor telephone consultation: Incoming phone calls were answered by a receptionist, who passed the message to a doctor. Call management options for the GP were: Telephone advice: on home management of the problem to see the patient’s own GP the next day to bring the patient to be examined at the primary care centre to take the patient to the accident and emergency department Examination of the patient at home or in the primary care centre with: advice on home management advice to see the patient's own GP the next day treatment admission to hospital Supervision, oversight: Nurses would refer calls to a GP if in doubt about how best to manage a situation, or would discuss the situation with the patient (in person at the centre or over the telephone). Before the end of every shift, triage nurses contacted the general practitioners on duty to report back on all calls they had managed. Formal, monthly professional supervision was provided by the trial project nurse.
Outcomes	Patient outcomes: Mortality Resource utilisation: Doctor workload Hospital referral and admission Emergency department visits Direct costs
Notes	Country: UK Study period: 3 to 7 days Nurse role: first contact care for patients with urgent problems out‐of‐hours Nurse title: not clear Nurse educational background: EQF level 6 Nurse years of experience: Nurses were required to have a minimum of 5 years of post registration experience, including experience in primary health care. Nurse additional training: 6‐week educational programme to prepare nurses for a 3‐month probationary period of supervised telephone triage practice. The taught component covered clinical skills (management of adult and child health problems and related pharmacology); telephone consultation (including professional and medicolegal aspects, communication, and interpersonal skills at different phases of the telephone encounter); assessment and decision‐making skills in telephone triage; approaches to managing a variety of situations on the telephone including ‘difficult’ calls using scenarios; skills in using the TAS system; and patient perspectives. Programme contributors were largely drawn from clinical GPs involved with the trial and academic staff. The programme comprised approximately 40 hours in total, with 20 hours taught over 6 weeks and 20 hours of individual practical work and assessment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The sequence process included a random component. "The trial year was divided into 26 blocks of two weeks. Within each block, one of each pair of matching out of hours periods ‐ for example, Tuesday evenings ‐ was randomly allocated to receive the intervention, the other being allocated to the normal service, by means of a random number generator on a Hewlett Packard 21S pocket calculator".
Allocation concealment (selection bias)	Low risk	Patients and investigators enrolling patients could not foresee assignment. "random number generator on a Hewlett Packard 21S pocket calculator"
Baseline characteristics	Low risk	Baseline characteristics were reported and were similar for both groups. "There were no substantial differences between the two trial groups".
Baseline outcome measurement	Unclear risk	Primary outcomes were not assessed before the intervention.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Personnel (low risk): "The complete pattern of intervention periods was known in advance only to the lead investigators and the trial coordinator. Nurses providing the intervention knew their shifts only after the duty roster for general practitioners providing out of hours care had been fixed. General practitioners were therefore blind to the intervention at the point at which they were able to choose or swap duty periods". Patients (unclear risk): no blinding; however it is unclear whether the outcome was influenced by lack of blinding of patients
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information
Incomplete outcome data (attrition bias) All outcomes	Low risk	Follow‐up of patients > 80%
Selective reporting (reporting bias)	Unclear risk	The protocol was not available.
Contamination	Unclear risk	No information
Bias due to lack of power	Low risk	Sufficient power. "..., we calculated that 5455 patients would be required in each arm of the trial using the formula described by Jones et al".