The Impact of Nurse Practitioner Full Practice Authority on Chronic Condition-Related Readmissions and Emergency Department Visits in the United States

Abstract

Background:

Chronic conditions affect over 60% of US adults and drive nearly 90% of the nation’s $4.9 trillion in annual health care costs. Nurse practitioners (NPs), particularly in Full Practice Authority (FPA) states, may be critical to improving outcomes and reducing health care burdens.

Objectives:

To evaluate whether nurse practitioner FPA reduces hospital readmissions and emergency department visits related to chronic conditions across the United States.

Research Design:

A secondary data analysis using restricted Medical Expenditure Panel Survey (MEPS) data (2010–2019) was performed on site at the Agency of Health Research and Quality. We applied incidence rate ratios (IRRs) and difference-in-difference (DiD) models.

Measures:

Primary outcomes included readmission and emergency visit rates for five chronic conditions: high cholesterol (n=33,409), high blood pressure (n=38,858), diabetes (n=13,075), emphysema (n=2,509), and asthma (n=17,018). Covariates included county-level socioeconomic factors and rurality.

Results:

States with FPA had modestly lower IRRs for high cholesterol (0.9863), high blood pressure (0.9758), diabetes (0.9746), and asthma (0.9710) compared with restricted states. DiD models showed inconsistent effects, with most FPA*Post coefficients lacking statistical significance. However, rural FPA counties frequently showed significantly lower readmission rates, notably for diabetes and high cholesterol.

Conclusions:

NP FPA is associated with slight reductions in chronic condition readmissions, particularly in rural areas. While DiD models showed limited policy-specific impact, IRR findings support FPA as a promising strategy to enhance chronic disease management and access to care. Future research should address model limitations and explore causal pathways.

Chronic conditions are a leading cause of illness, disability, and death in the United States, with a substantial impact on public health and health care spending.¹ According to the Centers for Disease Control and Prevention (CDC), 6 in 10 US adults live with at least one chronic disease, such as heart disease, stroke, diabetes, or chronic lung conditions, and 4 in 10 adults have 2 or more chronic illnesses.² These conditions are often long-lasting, generally incurable, require ongoing medical attention, and limit activities of daily living.³ Factors contributing to the high prevalence include aging populations, sedentary lifestyles, poor nutrition, tobacco use, and lack of access to preventive care.²

The incidence and prevalence of specific chronic conditions vary but collectively pose a significant burden on the health care system. High blood pressure and high cholesterol are among the most common, affecting nearly half and one third of US adults, respectively.^4,5 Diabetes continues to rise, with over 37 million Americans affected, many of whom are undiagnosed.⁶ Respiratory conditions like asthma and emphysema also affect millions and are often exacerbated by environmental and occupational factors.^7,8 Chronic conditions not only reduce quality of life but also drive nearly 90% of the nation’s $4.9 trillion in annual health care costs.⁹ As a result, public health initiatives increasingly focus on prevention, early detection, and chronic disease management to mitigate their impact

The rising prevalence of chronic conditions across the United States has placed an immense strain on the health care system, underscoring the urgent need for innovative and sustainable care models.¹⁰ Nurse practitioners (NPs), with their advanced clinical training and focus on holistic, patient-centered care, are uniquely positioned to address this growing challenge.¹¹ NPs are qualified to assess, diagnose, and manage a wide range of chronic illnesses, including hypertension, diabetes, asthma, and cardiovascular disease.¹² In both primary and specialty care settings, they provide education, promote lifestyle modifications, and ensure consistent follow-up, which are all critical components of effective chronic disease management. Their presence is especially vital in underserved and rural areas, where shortages of primary care physicians can hinder access to timely and continuous care.

Extensive research demonstrates that states granting full practice authority (FPA) to nurse practitioners (NPs) experience improved access to primary and preventive care, particularly in rural and underserved regions (eg, FPA implementation is associated with a higher probability of NPs residing in Health Professional Shortage Areas¹³). Additional studies show that NP-led care delivers quality of care comparable to physician models, with similar control of chronic disease markers, lower utilization in some settings, and no statistically significant differences in total costs.^14,15 Despite these benefits, gaps remain in understanding how FPA adoption translates into chronic condition patient outcomes at the national level, which this study aims to address.

Broadening the practice authority of nurse practitioners is not only a response to provider shortages but also a strategy for improving health outcomes and reducing costs.^14,16,17 Research has shown that NPs deliver care comparable in quality to that of physicians, with high levels of patient satisfaction and effective chronic disease control.^18,19 By removing restrictive practice barriers, NPs can more fully utilize their training and contribute to the health care system’s ability to meet the rising demands of chronic condition management. As the US population continues to age and the burden of chronic illness grows, empowering NPs is a critical step toward a more resilient and equitable health care system. Full Practice Authority (FPA), as defined by the American Association of Nurse Practitioners²⁰ (AANP), grants NPs the legal right to evaluate patients, diagnose, order and interpret diagnostic tests, and initiate and manage treatments—including prescribing medications—under the exclusive licensure authority of the state Board of Nursing rather than the state Medical Board. FPA removes the requirement for a formal physician collaborative agreement, thereby allowing NPs to practice to the full extent of their education and clinical training, while still permitting individual health care organizations to determine internal supervisory or collaborative structures as appropriate. Despite widespread policy discussions on the benefits of FPA, it remains unclear whether expanded NP practice authority translates into measurable improvements in chronic condition outcomes at the national level. Therefore, the purpose of this study was to determine whether the adoption of NP FPA is associated with reductions in hospital readmissions and emergency department visits related to chronic diseases, comparing outcomes between US states with and without FPA legislation.

METHODS

This study is a secondary analysis of restricted Medical Expenditure Panel Survey²¹ (MEPS) data.

Data Sources and Extraction

MEPS²¹ is a comprehensive, nationally representative survey conducted by the Agency for Healthcare Research and Quality (AHRQ) that collects detailed information on the health services used by Americans, the frequency and cost of those services, and how they are paid for. MEPS includes data on individual and household demographics, health conditions, insurance coverage, access to care, and expenditures related to medical services such as hospital stays, physician visits, prescriptions, and more. The survey is structured in a series of interview panels that follow participants over 2 years, enabling the analysis of health care use and cost trends over time.

Between February 19 and 21, 2025, our research team was granted restricted access to perform data analysis onsite at AHRQ under supervision and without internet access. Twenty-three states were approved by AHRQ to have state identifiers during the analysis phase; all other states were excluded. Control variables at the county level were merged into the data by AHRQ staff and anonymized before the researcher's arrival. This process, approved by AHRQ reviewers, allows the model to control for socioeconomic differences between counties without endangering data anonymity.

Our study focuses on identifying changes that are linked to FPA expansion, while maintaining a minimum amount of noise from prior or subsequent related legal changes. To do this, we follow the methodology developed by the Marian K. Shaughnessy Nurse Leadership Academy (MKSNLA) at Frances Payne Bolton School of Nursing, Case Western Reserve University. Many changes in practice authority for NPs occur incrementally, which makes the identification of the effect of FPA difficult. To eliminate that factor, an initial analysis by the legal research team of the statuary changes affecting NP practice in all 50 states was conducted.

Inclusion/Exclusion Criteria

Seven states were identified that did not have any other significant change in NP policy in the 4 years before or for a minimum of 2 years after achieving full practice authority (Connecticut, Delaware, Idaho, Maryland, Minnesota, Nebraska, and Nevada). AHRQ required the exclusion of most small population states to prevent patient identification, resulting in only 2 states of interest included as our treatment population. We do not identify which 2 states to preserve state-level data anonymity per the data agreement with AHRQ.

Control

Our control population included states with approved state identifiers that have never expanded to NP FPA; this equated to 14 control states. Remaining states were excluded for either having the FPA policy the entire period or expanding to FPA but failing to meet the inclusion criteria designed by MKSNLA, where the policy was passed and enacted during without the time of quiescence before and after the change that could cause noise within the data sample.

Data Analysis

We extracted several variables that identify if an individual has a chronic condition, if they visited a medical professional for this chronic condition, if that visit was an inpatient stay, if that visit was an emergency visit, or if the patient was readmitted within 30 days of an inpatient or emergency visit due to a chronic condition. Our data ranges from 2010 to 2019. The analysis was performed within a secure instance of Stata 17 at the AHRQ facility in Rockville, MD. Variations of the regress and irr (Report Incidence-Rate Comparison) packages were preinstalled in the Stata instance by AHRQ staff.

We analyzed the data on site using the incidence rate ratio (IRR) and difference-in-difference (DiD) analysis. Incidence rate ratio (IRR) analysis compares the rate of occurrence of an event between 2 groups over a specific time period by taking the ratio of their incidence rates. It allows for adjusting for person-time at risk, making it particularly useful in cohort studies with unequal follow-up times while providing a clear, interpretable measure of relative risk. DiD is a statistical method that estimates the causal effect of a treatment or policy by comparing the before-and-after changes in outcomes between a treatment group and a control group. DiD helps control for time-invariant unobserved confounders, allowing for more credible causal inference when randomization is not possible. Standard errors within the regressions are clustered at the state level. Results are consistent with robust standard errors and unclustered standard errors.

While DiD may be plausibly causal, we do not make causal claims from our data analysis. Due to data disclosure restrictions, we do not provide any information that may make a state identifiable, whether in our treatment or control group. The set of state identifiers allowed by AHRQ was selected for both having an ample sample size and representative of the national population. The 2 states in the treatment sample have the same enactment period for the FPA policy, which allows for a simple differencing framework and negates any need for adjustments due to heterogenous policy intervention timing.

RESULTS

The sample size for each chronic condition differs, as we investigated readmissions specific to individual chronic conditions (high cholesterol, n=33,409 observations; high blood pressure, n=38,858; diabetes n=13,075; emphysema n=2509; asthma n=17,018). IRR results of chronic conditions in FPA versus restricted NP practice authority states are found in Table 1. The DiD analysis results of NP practice authority for each chronic condition are found in Table 2.

TABLE 1.

Incident Rate Ratios of Chronic Conditions in Full Versus Restricted NP Practice Authority States

	High cholesterol	High blood pressure	Diabetes	Emphysema	Asthma
Restricted NP authority IRR	0.9910	0.9834	1.0019	0.9775	0.9908
Full NP practice authority IRR	0.9863	0.9758	0.9746	0.9850	0.9710
Pooled (direct)	0.9907	0.9829	1.0005	0.9777	0.9850
Standardized incidence	0.9907	0.9829	1.0005	0.9779	0.9895
Homogeneity	0.0000	0.0000	0.0000	0.0000	0.0000

TABLE 2.

Difference-in-Difference Analysis of NP Practice Authority Impact by Chronic Condition

High cholesterol (n=33,409)	(1)	(2)
FPA State	0.3971 (0.7242)	0.4073 (0.8513)
Post-policy change	0.2055 (0.3081)	0.1676 (0.3005)
FPA—post-policy	−0.7367 (0.6359)	0.2994 (0.9922)
Rural county		−1.9175*** (0.5638)
FPA—rural county		−1.4177** (0.6306)
High Blood Pressure (n=38,858)	(1)	(2)
FPA state	0.3971 (0.7242)	1.2914* (0.6903)
Post-policy change	0.2055 (0.3081)	0.5820* (0.3363)
FPA—post-policy	−0.7367 (0.6359)	2.7860 (1.7525)
Rural county		−0.6119 (0.5427)
FPA—rural county		−2.9420 (2.2014)
Diabetes (n=13,075)	(1)	(2)
FPA state	−0.3456 (1.7970)	−0.3431 (1.7967)
Post-policy change	0.0962 (0.4715)	0.0954 (0.4681)
FPA—post-policy	1.5248 (2.1338)	8.2030*** (1.955)
Rural county		−0.0620 (0.5901)
FPA—rural county		−8.8500*** (0.6946)
Emphysema (n=2509)	(1)	(2)
FPA state	5.2506*** (0.8117)	5.2785*** (0.8713)
Post-policy change	0.0503 (0.5052)	0.1861 (0.4978)
FPA–post-policy	−2.1893 (4.1978)	−5.5503*** (1.2093)
Rural county		3.1732*** (1.1126)
FPA—-rural county		5.0621 (1.0836)
Asthma (n=17,018)	(1)	(2)
FPA state	0.8284 (2.0017)	0.8965 (1.8501)
Post-policy change	1.0784** (0.4082)	1.0394* (0.4207)
FPA—post-policy	1.0471 (1.3278)	2.7160*** (0.7572)
Rural county		−2.3761*** (0.6888)
FPA—rural county		−2.0817 (0.9338)

Standard errors are clustered at the county-state pair level.

High Cholesterol

The incidence rate ratio (IRR) for readmissions related to high cholesterol is lower in full practice authority (FPA) states (0.9863) compared with restricted NP authority states (0.9910), suggesting a slight reduction in incidence under FPA. The pooled and standardized incidence values (both 0.9907) support this trend. The homogeneity score of 0.0000 indicates that the difference is statistically significant. However, the difference-in-difference (DiD) analysis shows no significant post-policy impact in FPA states, with an FPA*Post coefficient of −0.7367 (SE=0.6359) and 0.2994 (SE=0.9922) in the 2 models. Interestingly, rural counties show significantly lower rates of readmission due to high cholesterol (coefficient = −1.9175, SE=0.5638), especially those within FPA states (coefficient = −1.4177, SE=0.6306).

High Blood Pressure

The IRR analysis indicates a lower incidence of readmission of patients with high blood pressure in FPA states (0.9758) versus restricted states (0.9834), again pointing to a modest benefit under FPA. The pooled and standardized values (0.9829) align with this finding, with statistical significance indicated by the homogeneity value of 0.0000. However, the DiD model suggests no clear effect of FPA policy on readmission rates, as the FPA*Post coefficient is not statistically significant (2.7860, SE=1.7525). The rural-related coefficients are also not statistically significant, indicating limited or no impact from rurality in this context.

Diabetes

The IRR for readmission of diabetes patients is meaningfully lower in FPA states (0.9746) compared with restricted states (1.0019), with pooled and standardized values close to 1.0005, showing a statistically significant but small improvement. Despite this, the DiD analysis does not demonstrate a consistently significant impact of FPA on diabetes readmission. While one model shows a statistically significant increase post-policy (FPA*Post = 8.2030, SE=1.955), this result is considered unreliable due to a low R-squared value. Rural counties, however, show a strong inverse association with diabetes readmission rates under FPA (FPARural = −8.8500, SE=0.6946), which may suggest benefits of NP-led care in rural settings despite the noisy data.

Emphysema

Unlike other conditions, readmission for patients with emphysema has a higher IRR in FPA states (0.9850) than in restricted states (0.9775), indicating a relative increase in incidence under FPA. This difference is statistically significant based on the homogeneity measure. The DiD results, however, suggest a reduction in emphysema readmission rates when rural policies are considered. Specifically, the FPA*Post coefficient in Model 2 is −5.5503 (SE=1.2093), indicating a statistically significant post-policy decrease. Rural counties and FPA*Rural combinations also show higher baseline rates, which may reflect broader environmental or demographic trends in those areas.

Asthma

The IRR for readmission for patients with asthma is lower in FPA states (0.9710) compared with restricted states (0.9908), with a standardized incidence of 0.9895 and a pooled value of 0.9850, suggesting a beneficial effect of FPA on asthma incidence. Despite this, the DiD model does not show a consistent policy-related reduction. The FPA*Post coefficient in model 2 is positive and statistically significant (2.7160, SE=0.7572), but this result should be interpreted cautiously due to the noted limitations of the model’s explanatory power. Rural counties exhibit significantly lower asthma rates (coefficient = −2.3761, SE=0.6888), although rural effects under FPA are not statistically significant.

DISCUSSION

This study examined the relationship between nurse practitioner FPA and the incidence of readmission for patients with chronic conditions across the United States, with a specific focus on high cholesterol, high blood pressure, diabetes, emphysema, and asthma. The findings of this study provide evidence of modest but meaningful improvements in chronic disease outcomes in states that grant NPs full authority to practice independently, particularly for high cholesterol, high blood pressure, diabetes, and asthma. The exception to this trend was emphysema, where incidence was slightly higher in FPA states.

The incidence rate ratio (IRR) analysis findings that compare the rate of occurrence of an event between 2 groups over a specific time period by taking the ratio of their incidence rates suggest that FPA is associated with a lower incidence of chronic conditions. Specifically, FPA states showed lower IRRs for high cholesterol (0.9863 vs. 0.9910), high blood pressure (0.9758 vs. 0.9834), diabetes (0.9746 vs. 1.0019), and asthma (0.9710 vs. 0.9908), compared with restricted practice states. These results imply that when nurse practitioners are empowered to practice autonomously, they may contribute to better prevention, early identification, and management of chronic diseases. Standardized and pooled incidence rates further support this conclusion, with statistically significant differences indicated by homogeneity scores of 0.0000 for all conditions. The findings also suggest that expanding FPA may be a viable strategy for addressing chronic disease burdens in a cost-effective and scalable manner.

While the IRR results provide encouraging evidence of improved outcomes under FPA, the DiD results were mixed and must be interpreted with caution due to low R-squared values (below 0.01), which limit the reliability of these models. The statistical method that estimates the causal effect of a treatment or policy by comparing the before-and-after changes in outcomes between a treatment group and a control group, which controls for time-invariant unobserved confounders, allowing for more credible causal inference when randomization is not possible. For example, while the DiD model for diabetes showed a statistically significant increase in readmission for individuals with a diabetes diagnoses post-policy (FPAPost = 8.2030, SE=1.955), the overall low explanatory power of the model and the inverse relationship observed in rural FPA areas (FPARural = −8.8500, SE=0.6946) suggest more nuanced effects that could be influenced by access to care or improved screening rather than actual increases in disease burden. Similarly, while readmissions for patients with asthma showed an increased post-policy effect (FPA*Post = 2.7160, SE=0.7572), this contrasts with the IRR finding of lower overall incidence in FPA states, which may reflect differences in diagnosis patterns or health care utilization.

Our results also highlight the role of rurality in chronic disease outcomes. Across multiple conditions, rural counties with FPA often demonstrated lower incidence rates. For example, rural counties with FPA showed significantly lower readmission for high cholesterol (FPA*Rural = −1.4177, SE=0.6306) and lower readmission for patients with diabetes, indicating that expanded NP authority may be particularly beneficial in medically underserved areas. This is a critical finding given the persistent provider shortages and access challenges in rural America. Policies that support NP autonomy may help bridge these gaps by ensuring that patients receive timely and effective chronic disease management, reducing long-term health care costs and improving population health outcomes.

Policy Implications

Our finding that full practice authority (FPA) for nurse practitioners (NPs) is linked with modest reductions in readmissions for chronic conditions complements a growing body of literature showing that more expansive NP scope of practice is not only safe but also clinically effective. For example, McMichael²² (2025) reports that relaxing NP scope-of-practice laws leads to fewer hospitalizations for conditions manageable in outpatient settings. A systematic review of NP primary care models for patients with multiple chronic conditions similarly found that NP involvement is associated with equivalent or improved quality, lower or comparable costs, and reduced utilization of emergency and inpatient services.¹¹ Taken together, our findings and other aligned evidence support broader implementation of nurse practitioner FPA as a strategy for improving chronic disease management nationwide.

Specifically, our study shows the consistent pattern of reduced IRRs across readmissions for several high-burden chronic conditions, suggesting that NPs can effectively manage and mitigate these illnesses when granted full autonomy. Given the ongoing primary care physician shortage and rising demand for chronic disease care, especially in rural and underserved communities, expanding FPA laws across all states could help create a more resilient and accessible health care system.²³

Future policy should consider the growing body of evidence demonstrating the clinical effectiveness of nurse practitioners under FPA models.^13,24 State legislatures may benefit from revisiting restrictive scope-of-practice regulations that limit NP contributions, particularly in areas where health disparities and provider shortages are most severe. In addition, policymakers should invest in support systems that enable NPs to practice at the top of their license, including reimbursement reforms, clinical infrastructure, and interprofessional collaboration models. Further research with stronger statistical models and longitudinal data could also clarify the causal impact of FPA policies, particularly in diverse populations and across varying health care settings.

Limitations

One of the key limitations of the secondary data analysis methods used in this study is the reliance on observational data, which restricts the ability to establish definitive causal relationships between nurse practitioner FPA and chronic disease outcomes. These data are restricted by AHRQ and do not include data from all states, and our analysis is instead limited to 2 treatment states and 14 control states. While the states provided are a representative sample of national trends, our discussion does not allow for the discussion of individual state effects. Further, due to the nature of the supervised analysis and lack of access to the data for further hypothesis testing, we cannot further explore a relative increase in chronic care preventative visits in lower-income areas. Future research is recommended to further explore more granular analyses based on rurality, low-income areas, and the impact of NP supply in combination with FPA adoption in underserved areas.

Although IRRs offer useful insights, they cannot fully account for unmeasured confounding variables such as socioeconomic factors, regional health care policies, or variations in provider density. In addition, the DiD models demonstrated low explanatory power, with R-squared values below 0.01, indicating that the models explain very little of the variation in outcomes and may be subject to noise or spurious findings. Within these DiD estimates, the authors assume parallel trends in the pretreatment period. This weakens the reliability of conclusions drawn from the DiD analysis, and all results should be considered correlative. Furthermore, secondary datasets like MEPS, while robust, may contain inaccuracies due to self-reported data, underreporting of medical conditions, or misclassification of variables, particularly regarding rural status or provider authority across states. These limitations highlight the need for cautious interpretation and suggest that complementary methods, such as longitudinal cohort studies or randomized policy evaluations, could help validate and strengthen these findings.

CONCLUSIONS

The current study adds to the growing evidence base supporting nurse practitioner full practice authority. The observed reductions in readmissions for patients with chronic diseases in FPA states, particularly when viewed through the lens of IRR data, underscore the value of NPs as integral providers in the management of chronic conditions. Policy efforts to remove unnecessary restrictions on NP practice have the potential to significantly improve health outcomes and promote equitable access to care across the United States.