Esther Hing

Guide to Using Masked Design Variables to Estimate Standard Errors in Public Use Files of the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey

Until recently, sample design information needed to correctly estimate standard errors from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) public use files was not released for confidentiality reasons. In 2002, masked sample design variables were released for the first time with the 1995–2000 NAMCS and NHAMCS public use files. This paper shows how to use masked design variables to compute standard errors in three software applications. It also discusses when masking overstates or understates “in-house” standard errors, and how masking affects the significance levels of point estimates and logistic regression parameters.

Are There Patient Disparities When Electronic Health Records Are Adopted

Using nationally representative samples of visits from the 2005–2006 National Ambulatory Medical Care Surveys and the National Hospital Ambulatory Medical Care Surveys (N=39,343), this study examines whether electronic health record (EHR) systems have been adopted by primary care physicians or providers (PCPs) for poor minority patients at the same rate as by the PCPs for wealthier non-minority patients. Although we found that electronic health record adoption rates varied primarily by type of practice of the PCP, we also found that uninsured Black and Hispanic or Latino patients, as well as Hispanic or Latino Medicaid patients were less likely to have PCPs using EHRs, compared with privately-insured White patients, after controlling for PCPs’ practice type and location, as well as patient characteristics. This finding reflects a mixture of high and low EHR adopters among PCPs for poor minority patients.

Toward a More Complete Picture of Outpatient, Office-Based Health Care in the U.S.

The healthcare system in the U.S., particularly outpatient, office-based care, has been shifting toward service delivery by advanced practice providers, particularly nurse practitioners (NPs) and physician assistants (PAs). The National Ambulatory Medical Care Survey (NAMCS), conducted by the National Center for Health Statistics (NCHS) at the Centers for Disease Control and Prevention, is the leading source of nationally representative data on care delivered by office-based physicians. This paper first describes NAMCS, then discusses key NAMCS expansion efforts, and finally presents major findings from two exploratory studies that assess the feasibility of collecting data from NPs and PAs as sampled providers in NAMCS. The first NAMCS expansion effort began in 2006 when the NAMCS sample was expanded to include community health centers and started collecting and disseminating data on physicians, NPs, PAs, and nurse midwives in these settings. Then, in 2013, NCHS included workforce questions in NAMCS on the composition and clinical tasks of all healthcare staff in physician offices. Finally, in 2013-2014, NCHS conducted two exploratory studies and found that collecting data from NPs and PAs as sampled providers in NAMCS is feasible. However, modifications to the current NAMCS procedures may be necessary, for example, changing recruitment strategies, visit sampling procedures, and physician-centric survey items. Collectively, these NCHS initiatives are important for healthcare research, practice, and policy communities in their efforts toward providing a more complete picture of the changing outpatient, office-based workforce, team-based care approach, and service utilization in the U.S.

Emergency Department Visits and Resulting Hospitalizations by Elderly Nursing Home Residents, 2001–2008

This study examines emergency department (ED) visits by nursing home (NH) residents aged 65 and over, and factors associated with hospital admission from the ED visit using data from the 2001–2008 National Hospital Ambulatory Medical Care Survey. Cross-sectional analyses were conducted on patient characteristics, diagnosis, procedures received, and triage status. On average, elderly NH residents visited EDs at a rate of 123 visits per 100 institutionalized persons. Nearly 15% of all ED visits had ambulatory care sensitive condition diagnoses. Nearly half of these visits resulted in hospital admission; chronic obstructive pulmonary disease, congestive heart failure, kidney/urinary tract infection, and dehydration were associated with higher odds of admission. Previous studies suggested that adequate medical staffing and appropriate care in the NH could reduce ED visits and hospital admissions. Recent initiatives seek to reduce ED visits and hospitalizations by providing financial incentives to spur better coordination between NH and hospital.