Sixty-nine studies were included: 20 RCTs and 49 were observational studies. Eighteen RCTs were classified as high quality and two as low quality. Thirty-five observational studies were classed as high quality, 13 as low and one as high/low.
Thirty-seven studies compared nurse practitioner care groups to physicians (or teams without nurse practitioners). There were high levels of evidence for equivalent rates of patient satisfaction, self-reported perceived health, functional status, glucose control, blood pressure, emergency department visits, hospitalisation and mortality, and better serum lipid control. There were moderate levels of evidence for length of stay and low levels of evidence for duration of mechanical ventilation.
Twenty-one studies compared certified nurse-midwife managed care to physician managed care. There were high rates of evidence for nurse-midwife care being associated with lower rates of caesarian section, episiotomy, labour analgesia and third and fourth degree perineal lacerations. There were lower or comparable rates of vaginal operative deliveries and labour augmentation. There were equivalent rates of low birth weight and low Apgar scores and moderate levels of evidence for higher breastfeeding rates. There were comparable or higher rates of vaginal birth after caesarian, lower rates of epidurals and comparable or lower rates for neonatal intensive care admissions and labour induction.
Eleven studies assessed clinical nurse specialist care. Compared to controls there were high levels of evidence for equivalent rates of satisfaction and equivalent or lower length of stay and moderate levels of evidence for a decrease in complication rates.
Little data were available assessing certified registered nurse anaesthetists.