Table 5 Findings of studies
Outcome measured | Results | Interpretation |
|---|---|---|
Length of stay (LOS)—Emergency setting | ||
 Colligan et al. (2011) [33] | For patients who underwent procedures for their minor injuries, significant difference between study groups in the median LOS was present, 92 min (IQR 62–132) in NP group versus 135 min (96–200) in Registrars group (Mann-Whitney U test P < 0.0001). For patients who did not undergo any procedures, significant difference between study groups in the median LOS was also present, 119 min (IQR 68–154) in NP group versus 135 min (118–214) in Registrars group (Mann-Whitney U test P < 0.0002). | • A New Zealand study conducted at a single site. • Registrars took a longer time to see these minor injuries patients as the patients were of higher acuity with comorbidities while the ENP reviewed the straightforward minor injury cases. • NPs tend to complete patient care on their own while Registrars would delegate discharge or administrative tasks to clerical staff. • The time recorded electronically might not have been precise in reflecting the patient’s transit times. It was possible NPs logged onto the system to review patients faster than Registrars which might have account for the reduced LOS for NP-treated patients. |
 Jennings et al. (2008) [28] | Significant difference between study groups in the median ED LOS, 94 min (IQR 53.5–163.5) in the ENP candidate group versus 170 min (IQR 100–274) in the medical officers group (Wilcoxon P < 0.001). | • An Australian study conducted at a single site. • Patients in the ENP candidate group were from the Fast Track unit where patients of lower acuity were seen. Patients in the medical officers group were not only from the Fast Track unit. The medical officers might have reviewed more complex cases and hence, required more time. |
 Roche et al. (2017) [42] | No significant difference between study groups in median LOS, 97.0 min (IQR 91) in NP group versus 101.5 min (IQR 54) in medical officer group (Mann-Whitney U test P = 0.8). | • An Australian study conducted at three rural EDs. • Small sample size, underpowered study. • No significant differences between groups in baseline characteristics or acuity, NP service was comparable to that of senior medical officers. |
 Steiner et al. (2009) [32] | No significant difference between study groups in median ED LOS, 125 min (IQR 78–192) in NP group versus 123 min (IQR 76–184) in physician group (Wilcoxon P = 0.13). | • A Canadian study conducted at a single site. • The emergency physician group had patients of higher acuity than NP collaborative group yet there was no difference in LOS between groups, possibly implying it was more efficient to do without collaboration with NPs. • However, the demand for physicians to review lower acuity patients might have reduced with the collaborative NP group, allowing physicians to spend more time with higher acuity patients. |
Length of stay (LOS)—Critical Care setting | ||
 David et al. (2015) [35] | No significant difference found between study groups in the mean LOS in the inpatient telemetry cardiology unit and ICU, 129.1 ± 96.7 h in NP collaborative group versus 119.1 ± 69.7 h in physician-only group (P = 0.469). | • A USA study conducted at a single site. • Advocates for the NP collaborative model of care as it provides the unit staff with a consistent point of contact for the multidisciplinary team. • The NP collaborative model of care allows for NPs to develop expertise for managing a specific group of patients. |
 Goldie et al. (2012) [31] | No significant difference found between study groups in the mean hospital LOS, 9 ± 6 days in NP group versus 9 ± 14 days in hospitalist group (t test, P = 0.87). | • A Canadian RCT conducted at a single site. • Total sample size varied during the statistical analysis as there were varying amounts of missing data. • A much higher proportion of male participants recruited (86% in NP group and 81% in hospitalist group) raised queries about system level factors that might have favored male participants and the general willingness of female patients to participate in research. • The patient acuity in NP group was higher than that in hospitalist group and yet the groups did not differ in their clinical outcomes. |
 Hiza et al. (2015) [36] | No significant difference found between study groups in mean LOS, 4.91 ± 4.53 days in the NP collaborative group versus 6.02 ± 6.74 days in the physician group (Wilcoxon P = 0.1441). | • A USA study conducted at single site. • After subgroup analysis, significant differences in LOS were found between study groups in patients transferred from another service (Wilcoxon P < 0.0001), patients discharged to rehabilitation facility (Wilcoxon P = 0.0024), patients older than 60 years (Wilcoxon P = 0.0369), or patients discharged on intravenous antibiotics/wound therapy (Wilcoxon P = 0.0171). A significantly lower mean LOS was found in the NP collaborative group. • In this subgroup of patients, greater communication with multidisciplinary teams, discharge planning, follow-up care coordination and administrative work were required. This demonstrated the value of adopting the NP collaborative model of care. |
 Hoffman et al. (2006) [37] | No significant difference between study groups in the mean ICU LOS, 14.6 ± 9.7 days in NP collaborative group versus 15 ± 11.4 days in non-NP group (P = 0.753). | • A USA study conducted at a single site. • The comparable ICU LOS between NP collaborative model of care and the model of care without NP might be due to the greater continuity of care rendered by the NP as compared to the rotating coverage of the fellows in the non-NP model of care. • It might also be contributed by the attending physician’s ability to provide expert supervision and direct care of the patients, despite the difference in the composition of the team. • It could also be because the NP was highly experienced and was familiar with the environment and the patient care demands. |
 Landsperger et al. (2016) [38] | Significant difference between study groups in median ICU LOS, 3.4 ± 3.5 days in NP group versus 3.7 ± 3.9 days in Resident group (Wilcoxon P < 0.001). Similar odds of a longer ICU stay between groups (odds ratio 1.01, 95% CI 0.93–1.1, P = 0.81) Significant difference between study groups in median hospital LOS, 7.9 ± 11.2 days in NP group versus 9.1 ± 11.2 days in Resident group (Wilcoxon P < 0.001). NP group had lower odds of a longer ICU stay compared to Resident group (odds ratio 0.87, 95% CI 0.80–095 P = 0.001). | • An USA study conducted at a single site. • Large prospective cohort study (n = 9066). • Patients in NP group were solely managed by NPs and the supervising attending physicians and fellows. There was no cross-contamination, the Residents did not interfere with the management of patients in the NP group. • Even though LOS findings between study group favor the NP group, the lack of clear definition of the role of the acute care NP hinders direct comparison of clinical outcomes with the residents. • Hospital LOS for NP group was shorter than Resident group as more patients were being discharged straight from the ICU in NP group. It could have been due the differences in patient’s diagnosis, social or financial situations, or provider practice paradigm. • Shorter hospital LOS in NP group did not come at the expense of longer ICU LOS, increased ICU readmissions or post-discharge mortality. • A higher patient to provider ratio was observed in NP group but the authors were judicious in inferring that NP-led model of care had greater efficiency given the differences in the patients’ characteristics between study groups. |
 Morris et al. (2012) [40] | No significant difference between study groups in mean LOS, 6.5 ± 8.8 days for NP group versus 7 ± 10.8 days for Resident group (t test P = 0.17). | • A USA study conducted at a single site. • Although the results are not statistically significant, they were clinically important. The difference of 0.5 days multiplied by the number of patients in NP group (2759) accumulates to a total difference of greater than 1300 patient days. • A greater proportion of Resident group discharged to other health facilities which was delayed by bed availability. This could be a possible reason for the longer hospital LOS for patients in Resident group. • Daily multidisciplinary rounds were scheduled in NP group but not in Resident group which could have improved the coordination of patient care, contributing to shorter LOS. |
 Scherzer et al. (2016) [41] | Significant difference between study groups in mean MICU LOS, 7.9 ± 7.5 days in NP group versus 5.6 ± 6.5 days in Resident group (Wilcoxon P < 0.0001). No significant difference between study groups in mean hospital LOS, 18.0 ± 16.8 days in NP group versus 15.9 ± 19.9 days in Resident group (Wilcoxon P = 0.435). No significant difference between study groups in mean post-MICU discharge LOS, 6.4 ± 8.7 days in NP group versus 8.4 ± 15.6 days in Resident group (Wilcoxon P = 0.102). | • A USA study conducted at a single site. • Presence of differing clinical practice between NP and Residents could have contributed to the difference in MICU LOS. • Patients in NP group were older, more chronically and critically ill than patients in Resident group and so were more likely to require longer MICU care. • Patients in NP group had higher likelihood of being discharged to a post-acute care setting compared to patients in Resident group. The availability of the discharge facility could have attributed to MICU LOS. |
Waiting time (Time to consultation/Time to treatment) – Emergency setting | ||
 Colligan et al. (2011) [33] | Significant difference between study groups in median time to consultation, 14 min (IQR 5–27) in NP group versus 50 min (IQR 21–78) in Registrars group (Mann-Whitney U P < 0.0001). | • A New Zealand study conducted at a single site. • EM Registrars might have taken a longer time between each patient because they were of higher acuity and complexity compared to patients in NP group. • The time recorded electronically might not have been precise in reflecting the patient’s transit times. It was possible NPs logged onto the system to review patients faster than Registrars which might have account for the lesser wait times for NP-treated patients. |
 Dinh et al. (2012) [30] | No significant difference between study groups in median waiting time to be seen, 50 min (IQR 33–77) in NP group versus 57 min (IQR 31–110) in doctor group (P = 0.06). | • An Australian study conducted at a single site. • Lost to follow-up rates was high. The waiting time of patients who left before being seen was not captured. • Patients in both study groups had similar baseline characteristics. • Patients seen by NP and doctors had comparable waiting time to consultation. |
 Jennings et al. (2008) [28] | No significant difference between study groups in median time to consultation, 12 min (IQR 5.5–2.8) in the ENP candidate group versus 31 min (IQR 11.5–76) in medical officer group (Wilcoxon P < 0.001). | • An Australian study conducted at a single site. • Patients in the ENP candidate group were from the Fast Track unit where patients of lower acuity were seen. Patients in the medical officers group were not only from the Fast Track unit. The medical officers might have reviewed more complex cases and hence, required more time. |
 Jennings et al. (2015) [29] | Significant difference between study groups in the proportion of patients receiving analgesia within 30 min of ED arrival, 15.4% in NP group versus 1.6% in medical officer group (Chi-square test P < 0.001). | • An Australian study conducted at a single site. • NP group performed better at complying with the recommended Australian national targets for administering timely analgesia. • NP provided a hybrid model of care, assimilating nursing, and medical tasks. The NP could perform patient assessment, order and administer the analgesia which reduced the time to treatment. |
 Roche et al. (2017) [42] | No significant difference between study groups in median waiting time, 8 min (IQR 23) in NP group versus 7.5 min (IQR 20) in medical officer group (Mann-Whitney U test P = 0.4). | • An Australian study conducted at a single site. • Small sample size, underpowered study. • No significant differences between groups in baseline characteristics or acuity, NP service was comparable to that of senior medical officers. |
 Steiner et al. (2009) [32] | No significant difference between study groups in median time to consultation, 61 min (IQR 34–99) in NP group versus 65 min (IQR 35–105) in physician group (Wilcoxon P = 0.62). | • A Canadian study conducted at a single site. • The emergency physician group had patients of higher acuity than NP collaborative group yet there was no difference in waiting time between groups, possibly implying it was more efficient to do without collaboration with NPs. |
Waiting time (time to consultation/time to treatment)—Critical Care setting | ||
Significant difference between study groups in median door-to-needle time for acute ischemic stroke, 45 min (IQR 35–58) in NP group versus 53 min (IQR 45–73) in non-NP group (Mann-Whitney U P = 0.001). | • A USA study conducted at a single site. • Stroke code care pathway remained the same during the intervention period. • The reduced time interval between diagnostic imaging and the administration of treatment contributed to the reduction in door-to-needle time. • NP group was reviewed earlier upon stroke code activation as the NP service was 24/7. Necessary assessments commenced earlier. | |
Mortality—Critical Care setting | ||
 Hoffman et al. (2006) [37] | No significant difference between study groups in ICU mortality, 2% in NP collaborative group versus 2% in non-NP group without treatment limitation (Fisher’s exact test P = 1.0). | • A USA study conducted at a single site. • The comparable ICU mortality between NP collaborative model of care and the model of care without NP might be due to the greater continuity of care rendered by the NP as compared to the rotating coverage of the fellows in the non-NP model of care. • It might also be contributed by the attending physician’s ability to provide expert supervision and direct care of the patients, despite the difference in the composition of the team. • It could also be because the NP was highly experienced and was familiar with the environment and the patient care demands. |
No significant difference between study groups in ICU mortality (adjusted odds ratio 0.77, 95% CI 0.63–.94, P = 0.1). No significant difference between study groups in hospital mortality (adjusted odds ratio 0.87, 95% CI 0.73–1.03, P = 0.11) No significant difference between study groups in 90-day mortality (adjusted odds ratio 0.94, 95% CI 0.83–1.07, P = 0.36). No significant difference between study groups in longer term mortality (adjusted odds ratio 1.03, 95% CI 0.92–1.1 P = 0.65). | • An USA study conducted at a single site. • Large prospective cohort study (n = 9066). • Cross-contamination was minimized, the Residents did not interfere with the management of patients in the NP group. Patients in NP group were solely managed by NPs and the supervising attending physicians and fellows. • The 90 days and beyond information on the patient’s outcome strongly suggests that the quality of NP services in the ICU setting is high. | |
 Moran et al. (2016) [39] | No significant differences between study groups in hospital mortality, 12% in NP group versus 18% in non-NP group (chi-square test, P = 0.33). | • A USA study conducted at a single site. • Stroke code care pathway remained the same during the intervention period. • The involvement of the NP in the stroke code team did not change the overall tPA treatment rate of acute ischemic stroke patients because the final decision to treat lies with the stroke physician. |
 Scherzer et al. (2016) [41] | No significant difference between study groups in MICU, 14.5% in NP group versus 13.1% in Resident group (adjusted odds ratio 0.8, P = 0.441). No significant difference between study groups in hospital mortality, 24.4% in NP group versus 24.8% in Resident group (adjusted odds ratio 0.7, P = 0.072). | • A USA study conducted at a single site. • Patients in NP group were older, more chronically and critically ill than patients in Resident group yet the MICU and hospital mortality in both groups were comparable. • Administrative data was used to calculate the risk of mortality. Furthermore, only a subset of the patients had their ICU mortality score calculated. An exhaustive comparison to national data was not done. Outcomes were only compared within the single institution. |
 Skinner et al. (2013) [34] | No significant difference between study groups in ICU mortality, 2.8% in NP group versus 2.2% in junior resident group (chi-square test, P = 0.43). | • A UK study conducted at a single site. • The new model of care with NP providing first-line care was not inferior to that of usual model of care. • The junior surgeons had more training time in the operating theaters. |
Patient Satisfaction – Emergency setting | ||
 Dinh et al. (2012) [30] | Significant difference between study groups in overall rating categories. A higher proportion (68%) of patients in the NP group rated their care as excellent compared to the doctor group (50%) (Fisher exact test, P = 0.02). Significant difference between study groups in total patient satisfaction score, median score 23 (IQR 20–24) in NP group versus median score 21 (IQR 16–24) in doctor group (Students t test, P = 0.002). | • An Australian study conducted in a single site. • Loss to follow-up rates were high. The satisfaction level of these patients was not captured. |
 Roche et al. (2017) [42] | No significant difference between study groups in patient satisfaction of care at the occasion-of-service (Fisher’s exact test, P = 0.96). No significant difference between study groups in patient satisfaction of care at follow-up (Fisher’s exact tests, P = 0.98). | • An Australian study conducted at a single site. • Small sample size, underpowered study. • Evidence to show that majority of the patients were highly satisfied (88.5%) with NP services in the ED and was sustained over time (30 days). |
Patient satisfaction—Critical Care setting | ||
 Goldie et al. (2012) [31] | No significant difference between study groups in mean overall patient satisfaction score, 103 ± 11 in NP group versus 97 ± 14 in hospitalist group (independent t test, P = 0.10). | • A Canadian RCT conducted at a single site. • Although there was no significant difference between groups in overall patient satisfaction, patients rated NP services significantly higher on several patient satisfaction items. • The NPs were rated to perform better at teaching, answering questions, listening and pain management. • These are the forte of NPs, consistent with the NP goals and education, which are grounded in nursing. • The overall patient satisfaction score of NP group was higher than in the hospitalist group though not statistically significant, it was plausible Type II error happened, and a larger sample size would have generated statistical differences in the overall score. |
Cost—Critical Care setting | ||
 Hiza et al. (2015) [36] | Averagely, US$ 2 000 is incurred per day for hospitalization. For the subgroup of patients discharged to rehabilitation facility, a decrease in 2.63 days in the collaborative NP group of 122 patients could yield a cost savings of US$ 641 476 per year. For the subgroup of patients transferred from another service, similar cost analysis generated a total savings of US$ 1 059 480 per year. For the subgroup of patients who are 60 years and above, similar cost analysis generated a savings of US$ 790 240 per year. For the subgroup of patients discharged on IV antibiotics or wound therapy, similar cost analysis generated savings of US$ 478 240 per year. | • A USA study conducted at single site. • Direct costs were not determined • Indirect costs in terms of dollars saved per day were computed. • Cost analysis was only done for subgroups which had significantly different LOS. • Many patients were part of more than one subgroup hence, the cost-benefit analysis could not be additive. |
 Scherzer et al. (2016) [41] | No significant difference in charges observed between study groups, US$ 242 324.03 ± 235 749.24 in collaborative NP group versus US$ 216 726.51 ± 262 021.77 (t test, P = 0.561). | • A USA study conducted at a single site. • Despite the longer ICU LOS in the collaborative NP group, the overall hospital charges observed was comparable to that of the resident group. • Resource utilization was similar in both groups, supporting the contention that NPs are cost-effective healthcare providers. |
 Skinner et el. (2013) [34] | Annual staffing cost of NP and junior residents was £933 344 with the usual model of care and £764 691 with the collaborative NP model of care. | • A UK study conducted at a single site. • A reduction of staffing costs was observed. • Uncertain of how cost analysis was done. |