Dierick‐van Daele 2009.

Methods	Randomised trial
Participants	1501 patients (total group); mean age in intervention group 46.1, in control group 42.8; 38.2% male in intervention group, 40% male in control group 50 GPs 12 NPs
Interventions	Intervention: patients allocated to nurse practitioners Control: patients allocated to GPs Detailed description of the intervention: Compared 2 groups providing care to patients with common complaints as first point of contact The NP saw patients with respiratory and throat problems, ear and nose problems, musculoskeletal problems and injuries, skin injuries, urinary problems, gynaecological problems, and geriatric problems. The role of the NP involved assessing symptoms including physical examinations when appropriate and diagnosing and making decisions about further treatment, including writing prescriptions and referrals to primary or secondary services and clinical investigations. Supervision, oversight: The NP did not have full authority to prescribe medications, and so the GP was always available for consultation and for validation of prescriptions and referrals.
Outcomes	Patient outcomes: Satisfaction Burden of illness Quality of life Process of care measures: Adherence to clinical guidelines Appropriate medication prescribed Resource utilisation: Prescriptions Investigations Return visits Costs: direct healthcare costs, including and excluding productivity
Notes	Country: Netherlands Study period: 6 months Nurse role: first contact and ongoing care Nurse title: nurse practitioners Nurse educational background: EQF level 7 Nurse years of experience: 0 years as an NP, at least 2 years of experience as a registered nurse Nurse additional training: unknown
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The sequence process included a random component. "Sequentially‐numbered sealed envelopes containing randomised assignments to the two groups were provided by an independent person. The codes were generated from random number tables".
Allocation concealment (selection bias)	Low risk	Patients and investigators enrolling patients could not foresee assignment. "Sequentially‐numbered sealed envelopes containing randomised assignments to the two groups were provided by an independent person. The codes were generated from random number tables"
Baseline characteristics	Low risk	Baseline outcomes were reported and were similar for both groups. Only age was different. "Patients who returned all questionnaires were statistically significantly older (mean = 48Æ74, SD = 16Æ8) than those who did not (mean = 42Æ75, SD = 16Æ4; p < 0Æ001). There were no statistically significant differences in gender and type of diagnosis between patients with or without complete data. No statistically significant differences were noted between patients in two groups in terms of other (chronic) diseases".
Baseline outcome measurement	Unclear risk	Primary outcomes could not be assessed before the intervention.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Patients and care providers were not blind to the intervention. 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% "499 met one or more exclusion criteria, declined to participate, had no interest or were too ill". "58 patients who were allocated to the NP intervention group and 47 patients in the reference group did not attend the appointment they had booked or refused to participate because of being too ill or not having an interest".
Selective reporting (reporting bias)	Unclear risk	The protocol was not available.
Contamination	Low risk	It is unlikely that patients who visited the GP consulted the NP for the same question/problem, or vice versa. "Patients in the intervention group who did see the GP were excluded from analysis (n = 43)".
Bias due to lack of power	Unclear risk	No power calculation performed