Use of physician assistants and nurse practitioners in primary care, 1995-1999.

Federal policies and state legislation encourage the use of physician assistants (PAs) and nurse practitioners (NPs) in primary care, although the nature of their work has not been fully analyzed. In this paper we analyze primary care physician office encounter data from the 1995-1999 National Ambulatory Medical Care Surveys. About one-quarter of primary care office-based physicians used PAs and/or NPs for an average of 11 percent of visits. The mean age of patients seen by physicians was greater than that for PAs or NPs. NPs provided counseling/education during a higher proportion of visits than did PAs or physicians. Overall, this study suggests that PAs and NPs are providing primary care in a way that is similar to physician care.     

Primary Health Care in Community Health Centers and Comparison with Office-Based Practice

We examine the roles of nurse practitioners (NPs), physician assistants (PAs), and nurse midwives (CNMs) in community health centers (CHCs). We also compare primary care physicians in CHCs with office-based physicians. Estimates are from the National Ambulatory Medical Care Survey, a nationally representative annual survey of nonfederal, office-based patient care physicians and their visits. Analysis of primary care delivery in CHCs and office-based practices are based on 1,434 providers and their visits (n = 32,300). During 2006–2007, on average, physicians comprised 70% of CHC clinicians, with NPs (20%), PAs (9%), and CNMs (1%) making up the remainder. PAs, NPs, and CNMs provided care in almost a third of CHC primary care visits; 87% of visits to these CHC providers were independent of physicians. Types of patients seen by clinicians suggest a division of labor in caring for CHC patients. NPs and PAs were more likely than physicians to report providing health education services. There were no other differences among services examined. Office-based physicians were less likely to work alongside PAs/NPs/CNMs than CHC physicians. CHC staffing is contingent on a variety of providers. CHC staffing patterns may serve as models of primary care staffing for office practices as demand for primary care services nationwide increases.     

The Michigan Ambulatory Medical Care Survey: results and utility relative to the National Survey.

Percentage distributions for variables in the Michigan Ambulatory Medical Care Survey (MAMCS), both for the Detroit Standard Metropolitan Statistical Area (SMSA) and the State as a whole, are compared with those from the National Ambulatory Medical Care Survey (NAMCS). The MAMCS data are a subset of the NAMCS data, since the MAMCS was carried out by augmenting the NAMCS in Michigan. Differences in the impact of survey results for the three areas are examined in the context of planning and developing ambulatory health care services. A specific application of survey data is examined, namely, its use in planning the Health Care Institute of Wayne State University and the Detroit Medical Center. The survey results for the three areas are similar enough to warrant the use of data from the national survey in the planning and evaluation of health services locally, although special studies of a few items such as X-ray usage may be needed. To reestablish local credibility for national results, or to detect changes in patterns which may develop, another Statelevel survey is suggested at the time of a census. Based on the experience with the MAMCS, augmentation of the NAMCS or other national surveys would be used in other States.     

Autonomous ambulatory care by nurse practitioners and physician assistants in office-based settings

Data from the 1997 National Ambulatory Medical Care Survey were used to examine the autonomous provision of ambulatory medical care by nurse practitioners (NPs) and physician assistants (PAs) in physician-managed office-based settings. An estimated 6.81 million office visits involved autonomous care by NPs and PAs, for an overall rate of 2.55 visits per 100 persons. The visit rates were greatest for patients over 64 years of age, females, blacks, and patients from the Northeast. The visits encompassed a broad range of acute and chronic problems, with a greater proportion of non-illness care visits when compared with visits to physicians. While NPs and PAs provided diagnostic services and pharmacotherapy, there was more emphasis on therapeutic or preventive services in their practices than among physicians' practices. Predisposing, enabling, and need factors were differentially associated with visits to NPs and PAs. Utilization of NPs and PAs as autonomous providers in office-based settings appears limited. Public policy and educational initiatives can focus on predisposing, enabling, and need factors to increase access to autonomous practice of NPs and PAs in ambulatory care.     

Suitability of the National Health Care Surveys to Examine Behavioral Health Services Associated with Polycystic Ovary Syndrome

The National Institutes of Health, Office of Disease Prevention, has described polycystic ovary syndrome (PCOS) as a major public health problem for women in the USA. This study examines the suitability of the National Health Care Surveys, collected by the Centers for Disease Control and Prevention, to understand patient demographics and behavioral health services associated with PCOS-related medical visits. Data were from the 2005–2010 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey. PCOS-related medical visits were identified using the International Classification of Diseases, 9th Revision, Clinical Modification code 256.4. Items on mental health and health education ordered or provided did not meet the National Center for Health Statistics criteria necessary to produce reliable national estimates (i.e., at least 30 unweighted records and a relative standard error <30%). Findings underscore the need to strengthen national surveillance to further understand behavioral health care for patients with PCOS.     

The contribution of nurse practitioners and physician assistants to generalist care in Washington State

OBJECTIVE: To quantify the total contribution to generalist care made by nurse practitioners (NPs) and physician assistants (PAs) in Washington State. DATA SOURCES: State professional licensure renewal survey data from 1998-1999. STUDY DESIGN: Cross-sectional. Data on medical specialty, place of practice, and outpatient visits performed were used to estimate productivity of generalist physicians, NPs, and PAs. Provider head counts were adjusted for missing specialty and productivity data and converted into family physician full-time equivalents (FTEs) to facilitate estimation of total contribution to generalist care made by each provider type. PRINCIPAL FINDINGS: Nurse practitioners and physician assistants make up 23.4 percent of the generalist provider population and provide 21.0 percent of the generalist outpatient visits in Washington State. The NP/PA contribution to generalist care is higher in rural areas (24.7 percent of total visits compared to 20.1 percent in urban areas). The PAs and NPs provide 50.3 percent of generalist visits provided by women in rural areas, 36.5 percent in urban areas. When productivity data were converted into family physician FTEs, the productivity adjustments were large. A total of 4,189 generalist physicians produced only 2,760 family physician FTEs (1 FTE = 105 outpatient visits per week). The NP and PA productivity adjustments were also quite large. CONCLUSIONS: Accurate estimates of available generalist care must take into account the contributions of NPs and PAs. Additionally, simple head counts of licensed providers are likely to result in substantial overestimates of available care. Actual productivity data or empirically derived adjustment factors must be used for accurate estimation of provider shortages.     

Use of midlevel practitioners to achieve labor cost savings in the primary care practice of an MCO

OBJECTIVE: To estimate the savings in labor costs per primary care visit that might be realized from increased use of physician assistants (PAs) and nurse practitioners (NPs) in the primary care practices of a managed care organization (MCO). STUDY SETTING/DATA SOURCES: Twenty-six capitated primary care practices of a group model MCO. Data on approximately two million visits provided by 206 practitioners were extracted from computerized visit records for 1997-2000. Computerized payroll ledgers were the source of annual labor costs per practice from 1997-2000. STUDY DESIGN: Likelihood of a visit attended by a PA/NP versus MD was modeled using logistic regression, with practice fixed effects, by department (adult medicine, pediatrics) and year. Parameter estimates and practice fixed effects from these regressions were used to predict the proportion of PA/NP visits per practice per year given a standard case mix. Least squares regressions, with practice fixed effects, were used to estimate the association of this standardized predicted proportion of PA/NP visits with average annual practitioner and total labor costs per visit, controlling for other practice characteristics. RESULTS: On average, PAs/NPs attended one in three adult medicine visits and one in five pediatric medicine visits. Likelihood of a PA/NP visit was significantly higher than average among patients presenting with minor acute illness (e.g., acute pharyngitis). In adult medicine, likelihood of a PA/NP visit was lower than average among older patients. Practitioner labor costs per visit and total labor costs per visit were lower (p<.01 and p=.08, respectively) among practices with greater use of PAs/NPs, standardized for case mix. CONCLUSIONS: Primary care practices that used more PAs/NPs in care delivery realized lower practitioner labor costs per visit than practices that used less. Future research should investigate the cost savings and cost-effectiveness potential of delivery designs that change staffing mix and division of labor among clinical disciplines.     

National patterns of physician activities related to obesity management

CONTEXT: National physician practices related to the clinical recognition and management of obesity are unknown. OBJECTIVES: To estimate national patterns of office-based, obesity-related practices and to determine the independent predictors of these practices. DESIGN: Serial cross-sectional surveys of physician office visits. SETTING: Ambulatory medical care in the United States. PATIENTS: We analyzed 55,858 adult physician office visits sampled in the 1995-1996 National Ambulatory Medical Care Surveys. Data from the Third National Health and Nutrition Examination Surveys, 1988-1994 were used to assess and, then, adjust for the underreporting of obesity. MAIN OUTCOME MEASURES: Reporting of obesity at office visits and physician counseling for weight loss, exercise, and diet among patients identified as obese. RESULTS: Physicians reported obesity in only 8.6% of 1995-1996 National Ambulatory Medical Care Surveys visits. The 22.7% prevalence rate of the Third National Health and Nutrition Examination Surveys, 1988-1994 suggests that physicians reported obesity in only 38% of their obese patients. Among visits by patients identified as obese, physicians frequently provided counseling for weight loss (35.5%), exercise (32.8%), and diet (41.5%). Adjusted for population prevalence; however, each service was provided to no more than one quarter of all obese patients. While patients with obesity-related comorbidities were treated more aggressively, in these patients, weight loss counseling occurred at only 52% of the visits. CONCLUSIONS: Specific interventions to address obesity are infrequent in visits to US physicians. Obesity is underreported and interventions are only moderately likely among patients identified as obese, even for those with serious obesity-related comorbidities.     

Making patient-level estimates from medical encounter records using a multiplicity estimator

The National Ambulatory Medical Care Survey (NAMCS) is a nationally representative survey of medical encounters in physician offices in the United States. Data from this survey and its counterpart in hospitals, the National Hospital Ambulatory Medical Care Survey (NHAMCS), have been used to investigate physician treatment and prescribing patterns. A limitation of these data, however, is that they represent visits rather than patients. Starting in 2001, the survey questionnaires began collecting information on the number of past visits the patient had to the sample provider during the one-year period prior to the sampled visit. This information was used to estimate number of patients from the NAMCS and NHAMCS visit data using a multiplicity estimator. The resulting distribution of patients by the number of annual visits is similar to the distribution of persons in the U.S. making ambulatory care visits from a population-based survey. This estimation technique may be useful in estimating patients with clinical characteristics that are difficult to collect from a population-based survey. Published in 2007 by John Wiley & Sons, Ltd.     

PHB6 Health Care Use in Women Age 45 and Older

Key components of preventive health care for middleaged and older women include evaluating the risk for osteoporosis and coronary artery disease, considering hormone replacement therapy (HRT), and cancer screening. HRT is effective for treating the symptoms of acute menopause, and it may prevent some chronic health problems associated with growing older. However, HRT may increase the risks for other diseases.
OBJECTIVE: The purpose of this study was to estimate the level of health care use and costs incurred by post-menopausal women for conditions that have been associated with HRT.
METHODS: National health care survey and discharge data were used to estimate health care use by women age 45 and older for cardiovascular disease, osteoporosis, breast cancer, uterine cancer, and deep-vein thrombosis/ pulmonary embolism. The databases used were the Healthcare Utilization Project-3, National Ambulatory Medical Care Survey, National Hospital Ambulatory Medical Care Survey, National Nursing Home Survey, and National Home and Hospice Care Survey. Clinical Classification for Health Policy Research codes were used to identify patients whose primary diagnosis or procedure corresponded with the above conditions. National weights were used to estimate resource use. Treatment costs were estimated using cost-to-charge ratios or Medicare Fee Schedule to calculate costs of individual procedures.
RESULTS: For each of the five conditions, resource use and costs are reported for hospitalization, outpatient, nursing home, and home health care services. Resource use and costs are also reported by age and race/ethnicity.
CONCLUSION: Results of the study may be used to estimate the burden of disease for conditions commonly affecting postmenopausal women and to provide data for cost-effectiveness models comparing newly developed drugs to existing HRTs.     

Mental illness surveillance among adults in the United States

Mental illnesses account for a larger proportion of disability in developed countries than any other group of illnesses, including cancer and heart disease. In 2004, an estimated 25% of adults in the United States reported having a mental illness in the previous year. The economic cost of mental illness in the United States is substantial, approximately $300 billion in 2002. Population surveys and surveys of health-care use measure the occurrence of mental illness, associated risk behaviors (e.g., alcohol and drug abuse) and chronic conditions, and use of mental health-related care and clinical services. Population-based surveys and surveillance systems provide much of the evidence needed to guide effective mental health promotion, mental illness prevention, and treatment programs. This report summarizes data from selected CDC surveillance systems that measure the prevalence and impact of mental illness in the U.S. adult population. CDC surveillance systems provide several types of mental health information: estimates of the prevalence of diagnosed mental illness from self-report or recorded diagnosis, estimates of the prevalence of symptoms associated with mental illness, and estimates of the impact of mental illness on health and well-being. Data from the CDC 2005-2008 National Health and Nutrition Examination Survey indicate that 6.8% of adults had moderate to severe depression in the 2 weeks before completing the survey. State-specific data from the CDC 2006 Behavioral Risk Factor Surveillance System (BRFSS), the most recent BRFSS data available, indicate that the prevalence of moderate to severe depression was generally higher in southeastern states compared with other states. Two other CDC surveys on ambulatory care services, the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, indicate that during 2007-2008, approximately 5% of ambulatory care visits involved patients with a diagnosis of a mental health disorder, and most of these were classified as depression, psychoses, or anxiety disorders. Future surveillance should pay particular attention to changes in the prevalence of depression both nationwide and at the state and county levels. In addition, national and state-level mental illness surveillance should measure a wider range of psychiatric conditions and should include anxiety disorders. Many mental illnesses can be managed successfully, and increasing access to and use of mental health treatment services could substantially reduce the associated morbidity.     

Adequacy of two ambulatory care surveillance systems for tracking childhood obesity practice patterns

BACKGROUND: The National Ambulatory Medical Care Surveys (NAMCS) and National Hospital Ambulatory Medical Care Surveys (NHAMCS) are surveillance systems in the USA that track provider practice patterns at ambulatory care visits. This study investigated the adequacy of the NAMCS/NHAMCS for surveillance of childhood obesity practice patterns. METHODS: The frequency of obesity visits in the 1997-2000 NAMCS/NHAMCS (outpatient component) was compared with obesity prevalence among children who reported a physician visit in the preceding 12 months in the National Health and Nutrition Examination Survey (NHANES) 1999-2000. Obesity was identified using the International Classification of Diseases 9th revision clinical modification code ICD-9-278.0 in the NAMCS/NHAMCS. For the NHANES, age- and gender-specific body mass index >95th percentile was used. RESULTS: Between 1997 and 2000, obesity was identified in 4.1 million (0.8%) of 516 million ambulatory care visits. With an obesity prevalence of 14.2% from the NHANES survey, NAMCS/NHAMCS only identified 5.6% of all children aged 2-17 years >95th percentile. Of those identified, the rate of obesity visits in the NAMCS/NHAMCS was lowest for non-Hispanic Whites (3.9%) compared with non-Hispanic Blacks (6.9%) and Hispanics (10.2%). CONCLUSION: The very infrequent reporting of obesity in the NAMCS/NHAMCS suggests that these surveillance systems do not reflect how healthcare providers identify and care for overweight children. Collecting weight and height measures would improve their utility in tracking identification and management of overweight children.     

The professional role of physician's assistants in adult ambulatory care practices.

This article describes the methodology and findings of a national survey of Physician's Assistants (PAs) in adult, ambulatory care practices. Data on patient care roles and other professional activities were collected for a three-day period via a comprehensive self-reporting, log-diary instrument. Completing the instrument were 356 (50.4%) PAs. Survey results address the following questions: What is the typical work week for PAs? How do PAs allocate their time in a professional day? What direct patient care services do PAs provide? How productive are PAs with respect to number of patients seen and dollar income generated? In general, the data are consistent with the PA role model of a primary health care professional who provides basic health care services with an emphasis on patient counseling and disease prevention.     

National Hospital Ambulatory Medical Care Survey: 1998 emergency department summary

OBJECTIVES: This report describes ambulatory care visits to hospital emergency departments in the United States. Statistics are presented on selected patient and visit characteristics. METHODS: The data presented in this report were collected from the 1998 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is part of the ambulatory care component of the National Health Care Survey that measures health care utilization across various types of providers. NHAMCS is a national probability survey of visits to hospital emergency and outpatient departments of non-Federal, short-stay, and general hospitals in the United States. Sample data are weighted to produce annual national estimates. RESULTS: During 1998, an estimated 100.4 million visits were made to hospital emergency departments (ED's) in the United States, about 37.3 visits per 100 persons. Persons 75 years and over had the highest rate of ED visits. There were an estimated 37.1 million injury-related ED visits during 1998, or 13.8 visits per 100 persons. Seventy-four percent of injury-related ED visits were made by persons under 45 years of age. Injury visit rates were higher for males than females in each age group under 45 years. According to ICD-9-CM classification, 77.2 percent of injury visits were unintentional. About 71 percent of the ED visits involved medication therapy, with pain relief drugs accounting for 31.5 percent of the medications mentioned. Acute upper respiratory infection was the leading illness-related diagnosis at ED visits.     

Staphylococcus aureus-associated skin and soft tissue infections in ambulatory care

To describe the number and treatment of skin and soft tissue infections likely caused by Staphylococcus aureus in the United States, we analyzed data from the 1992-1994 and 2001-2003 National Ambulatory Medical Care Surveys and National Hospital Ambulatory Medical Care Surveys. Each year, data were reported by an average of 1,400 physicians, 230 outpatient departments, and 390 emergency departments for 30,000, 33,000, and 34,000 visits, respectively. During 2001-2003, the number of annual ambulatory care visits for skin and soft tissue infections was 11.6 million; the visit rate was 410.7 per 10,000 persons. During the study period, rates of overall and physician office visits did not differ; however, rates of visits to outpatient and emergency departments increased by 59% and 31%, respectively. This increase may reflect the emergence of community-acquired methicillin-resistant S. aureus infections.     

Use of health services for disorders of the female reproductive system: United States, 1977-78

Using data from the National Ambulatory Medical Care Survey and the National Hospital Discharge Survey, statistics are presented on visits to office-based physicians for care and treatment of female reproductive disorders and on patients discharged from short-stay hospitals with related surgery. Visits are described in terms of patient, physician, and clinical characteristics. Breast and gynecological surgery is shown in terms of associated diagnoses and is charted for 1970-78.     

Antimicrobial drug prescription in ambulatory care settings,United States, 1992-2000

During the 1990s, as antimicrobial resistance increased among pneumococci, many organizations promoted appropriate antimicrobial use to combat resistance. We analyzed data from the National Ambulatory Medical Care Survey, an annual sample survey of visits to office-based physicians, and the National Hospital Ambulatory Medical Care Survey, an annual sample survey of visits to hospital emergency and outpatient departments, to describe trends in antimicrobial prescribing from 1992 to 2000 in the United States. Approximately 1,100-1,900 physicians reported data from 21,000-37,000 visits; 200-300 outpatient departments reported data for 28,000-35,000 visits; approximately 400 emergency departments reported data for 21,000-36,000 visits each year. In that period, the population- and visit-based antimicrobial prescribing rates in ambulatory care settings decreased by 23% and 25%, respectively, driven largely by a decrease in prescribing by office-based physicians. Antimicrobial prescribing rates changed as follows: amoxicillin and ampicillin, -43%; cephalosporins, -28%; erythromycin, -76%; azithromycin and clarithromycin, +388%; quinolones, +78%; and amoxicillin/clavulanate, +69%. This increasing use of azithromycin, clarithromycin, and quinolones warrants concern as macrolide- and fluoroquinolone-resistant pneumococci are increasing.     

Adverse drug events in U.S. adult ambulatory medical care

Objective. To estimate the incidence of adverse drug events (ADEs) associated with health care visits among U.S. adults across all ambulatory settings. Data Source. We analyzed data from two nationally representative probability sample surveys: the National Ambulatory Medical Care Survey and the National Hospital and Ambulatory Medical Care Survey. From 2005 to 2007, the presence of an ADE was specifically defined, requested, and recorded in these surveys. Study Design. Secondary data analysis. Principal Findings. An estimated 13.5 million ADE‐related visits occurred between 2005 and 2007 (0.5 percent of all visits), the large majority (72 percent) occurring in outpatient practice settings, and the remaining in emergency departments. Older patients (age ≥65 years) had the highest age‐specific ADE rate, 3.8 ADEs per 10,000 persons per year. In adjusted analyses of outpatient visits, there was an increased odds of an ADE‐related visit with increased medication burden (odds ratio [OR] for six to eight medications compared with no medications, OR 3.83 [2.20, 6.65]), and increased odds of ADEs associated with primary care visits compared with specialty visits (OR 2.22 [1.70, 2.89]). Conclusions. Approximately 4.5 million ambulatory visits related to ADEs occur each year, the majority of these in outpatient office practices. A greater focus on ADE prevention and detection is warranted among patients receiving multiple medications in primary care practices.