The Quality and Effectiveness of Care Provided by Nurse Practitioners

Julie Stanik-Hutt, PhD, ACNP-BC; Robin P. Newhouse, PhD, NEA-BC; Kathleen M; White, PhD, NEA-BC; Meg Johantgen, PhD, RN; Eric B. Bass, MD, MPH; George Zangaro, PhD, RN; Renee Wilson, MS; Lily Fountain, MS, CNM; Donald M. Steinwachs, PhD; Lou Heindel, DNP, CRNA; Jonathan P. Weiner, DrPH


Journal for Nurse Practitioners. 2013;9(8):492-500.e13. 

In This Article

Integration of Results With Previous Knowledge


Results related to NP care quality found in this systematic review echoed previous reviews in that patient satisfaction with care in primary, outpatient surgical, and inpatient settings was similar to that associated with care from MDs.[19–23,26,27] Some previous reviews found that satisfaction with NP care was better.[21–23,27] This review included satisfaction data obtained from samples of adults and from parents of traumatically injured children and children undergoing surgery. Outcomes of health status and physical function in patients in ambulatory, home, and inpatient care settings did not differ, regardless of whether cared for by an NP or an MD. Samples of well adults and elders, as well as those with chronic illnesses and even hospitalized individuals, were included in the health and functional status reports. Previous systematic reviews and meta-analyses found similar results for these 2 care quality outcomes.[21–23,26,27]

The comparability of impact of NPs and MDs in minimizing ED visits in samples of healthy children, adults, and elders, as well as those with chronic or debilitating illnesses, also did not differ from findings of previous reviews.[20,25,26] The finding of comparability on rates of hospitalization among well adults, well and debilitated elders, high-risk neonates, and chronically ill children was similar to findings of previous reviews.[21,26,27] While 1 previous systematic review reported a shorter LOS associated with NP care,[26] this review found that LOS, for a variety of medical and surgical problems across all age groups, was comparable among patients cared for by either provider group. This is the first review to report on influence of provider type on ventilation duration.


Patient safety is influenced by many variables related to patient, care setting, and provider. These potentially confounding influences make it difficult to measure and interpret safety outcomes data. Mortality was the only safety outcome aggregated in this review.[34,35,38,39,42,43,52,68]

Reports of NP care impact on other patient safety outcomes, such as medication errors, falls, hospital-acquired infections, pressure ulcers, etc, were not found. While mortality alone is a relatively insensitive care outcome measure, it is a commonly reported patient outcome in many types of research. This review is the first to report on comparability among provider teams for the safety outcome of mortality.[34,35,38,39,42,43,52,68] This could be because this systematic review, in contrast to previous studies of outcomes from primary care only,[19–27] incorporated evidence from NPs practicing in any setting and included nursing home residents and hospitalized high-risk neonates, children, and adults.[33–40,42–44,51,53,65–67] Studies from these additional settings would naturally be more likely to report on mortality. More research is needed regarding a broad variety of safety outcomes.


Results related to NP care effectiveness from this systematic review were reminiscent of those previously reported. Primary ambulatory care involving NPs resulted in similar though not better blood pressure and blood glucose control.[21,27] This review found that NP care was associated with better lipid control and is the first systematic review or meta-analysis to report on this particular patient outcome.[45,55,69] Additional research is needed on this outcome and for a broader variety of care effectiveness outcomes.

Methodological Issues

Although all the reviewers were nurses, the investigator team included 2 experts in the evaluation of heath care quality and effectiveness and a physician with extensive experience conducting systematic reviews. Articles included in the review were published in peer-reviewed medical (n = 12),[33,37,39,45,48,51,52,56,57,59,61,64] interprofessional (n = 10)[34,36,38,43,46,47,49,53,55,60] and nursing (n = 15) journals.[35,40–42,44,50,54,58,62,63,65–69] A draft of the report was reviewed by 2 independent panels of technical experts: 1 panel comprised a consumer, a statistician, and a physician leader; the other included highly respected NPs. Written comments and recommendations from these reviewers were addressed by the authors.

Limitations in the body of research reviewed should be considered when interpreting the results of this systematic review. Heterogeneity of study designs and measures, multiple time points for measuring outcomes, limited number of randomized designs, and inadequate statistical data for meta-analysis were among the methodological limitations encountered. Diffusion of treatment because of inclusion of MDs in both experimental and usual care groups was also a potential problem in some studies.[33,34,58,60,66] In addition, the failure to fully describe the nature of the NP roles and responsibilities and the relationships of team members, including frequency and qualities of collaboration with MDs, limits the ability to replicate the models of care employed.

To address some of the limitations, the use of a modified Jadad quality score provided clear, standardized methods to ensure a robust process, including the assessment of differences in comparison groups, settings, participants, and attribution. Application of the GRADE working group criteria when assessing aggregated outcomes also disciplined decision making regarding conclusions that could be drawn.

NP Autonomy vs Team

When assessing attribution of the outcomes to the NP, it was not always clear if the NPs practiced autonomously.[50,53,62] Conversely, it was apparent that some study protocols restricted NP activities to a narrower scope of practice than is legally authorized.[42,57,58,59] Mirroring the complexities of care today, some protocols used elaborate team interventions that included care from an NP but made it difficult to directly attribute the outcome to the NP exclusively.[45,57] Sometimes the NP assumed responsibilities that were previously borne by an attending MD, freeing that MD for other activities.[58,60,66] NPs were also substituted for house staff MDs.[33,34] Attribution of the specific outcome to the NP was especially complicated when studies were conducted in acute care hospitals because NPs in those settings (neonatal and pediatric or adult acute care NPs) often practice as part of a team.[25,36–40,43,44,65,66,68]

While this review was not designed to compare NPs to MDs, MDs were the comparison group in all but 1 of the studies included. This comparison is not unexpected since the NP role was developed to mitigate problems with access to care related to a shortage of primary care MDs. In addition to providing advanced nursing services (family-focused care, patient education, support of self-care management, care coordination, interprofessional communication and collaboration, etc.), NP practice activities, roles, and responsibilities are often similar to those of MDs, and NPs and MDs often work in the same practices or settings.

Future studies should examine models of care in which patient needs and provider abilities are matched to maximize utilization of all provider types to address health needs. If needs can be met by NPs, then systems should incorporate NPs to the fullest extent possible. This structure would free MDs to attend to patient needs that demand their scope of capabilities. Health care systems could then be better designed to ensure that the right professionals are available to address each patient's needs.

Future research also needs to allow a fuller examination of the outcomes of care provided by NPs in states with full legal practice authority. Future studies need to include additional care settings (eg, rural communities, private practices) and patient populations (eg, primary care of children, individuals with mental health problems). They should also compare outcomes from different providers to accepted effectiveness measures.