Lewis 1967.

Methods	Randomised trial
Participants	66 patients (total group), 16+ years, 12% male Unknown numbers of nurses and doctors
Interventions	Intervention: patients allocated to nurse‐led care Control: patients allocated to doctor‐led care Detailed description of the intervention: Compared 2 groups delivering care to patients with chronic illnesses: Nurse clinic: nurses as the primary source of care for adults with chronic illnesses (i.e. hypertensive cardiovascular disease; arteriosclerotic heart disease; exogenous obesity; psychophysiological reactions; and arthritis) Control: medicine clinic Supervision, oversight: unknown
Outcomes	Patient outcomes: Health status Provider preference Compliance with follow‐up attendance Resource utilisation: Direct costs
Notes	Country: USA Study period: 12 months Nurse role: ongoing primary care for patients with stable chronic disease Nurse title: not clear Nurse educational background: EQF level unknown Nurse years of experience: unknown Nurse additional training: unknown
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information
Allocation concealment (selection bias)	Unclear risk	No information
Baseline characteristics	Low risk	Baseline characteristics were reported and were similar for both groups. "There were no differences among the scores of the two groups on initial testing".
Baseline outcome measurement	Low risk	Baseline outcomes were reported and were similar for both groups.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not performed It is unclear whether the outcome was influenced by lack of blinding of patients and care providers.
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	High risk	Potential contamination represented by cross‐over of patients/clinicians between groups "On 95% of these occasions, patients were seen by the nurse alone".
Bias due to lack of power	Unclear risk	No power calculation performed