# Presentation: 377683

## Women’s health: Data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS)

- Esther Hing, Ambulatory Care Statistics Branch, Division of Health Care Statistics

## Outline

- Provide overview of NAMCS
- Provide overview of NHAMCS
- Emergency Departments (EDs)
- Outpatient Departments (OPDs)
- Content of NAMCS and NHAMCS (OPD and ED) Patient Record form (PRF)
- Examples research on women’s health using NAMCS and NHAMCS data

## Related NAMCS/NHAMCS sessions

- Overview of NAMCS/NHAMCS (10)
- Using Past Visits information to Enhance NAMCS Data (25)
- Hands on NAMCS/NHAMC Workshop (39,44)
- Prescription Drug Use (48)

## National Ambulatory Medical Care Survey (NAMCS)

- Nationally representative survey of patient visits to non-federally employed  physicians providing office-based patient care
- The NAMCS is a three-stage probability design
- 112 NHIS PSUs
- 3,000 physicians
- 25,000 visits sampled
- 1-week reporting period

## National Hospital Ambulatory Medical Care Survey (NHAMCS)

- Nationally representative survey of visits made to emergency departments (EDs) and outpatient departments (OPDs) of non-Federal, short-stay hospitals
- The NHAMCS is a four-stage probability design
- 112 NHIS PSUs
- 500 hospitals
- 400 EDs and 250 OPDs
- 37,000 ED visits and 35,000 OPD visits
- 4-week reporting period.

## NAMCS and NHAMCS Data

- NAMCS and NHAMCS are record-based surveys
- Data abstracted from the patient’s medical record by the physician and/or his staff, hospital staff, or interviewer
- Estimates are in terms of visits and not persons
- Population-based surveys (NHIS) estimates persons

- NAMCS/NHAMCS provide information from the physician’s perspective
- Diagnoses and services provided have high validity
- Data less subject to respondent recall
- Public use files released on the internet include input statements to assist users creating files in SAS, SPSS, and STATA software

## Content of NAMCS and NHAMCS

- Data collection instrument: Patient Record form (PRF)
- PRFs are revised every 2-3 years
- Items collected every year include demographics, payment source, reason for visit, diagnoses, services received, medications, providers seen, and disposition
- Service and other data items may change with each PRF revision

## Content of NAMCS and NHAMCS

- Physician diagnoses
- Medications prescribed or ordered
- Mammography (PO/OPD:1992, 1997-present)
- Pap test (PO/OPD:1997 to present)
- Breast and pelvic exam (PO/OPD:1997-2000)
- Pregnancy test (ED:1995-present, PO/OPD:1997-2000)
- STD/HIV prevention education (PO/OPD:1993-2000)
- Preventive care visits (PO/OPD:2001 to present)

## Slide 10

## Previous research on women’s health using NAMCS and NHAMCS data 

- Preventive services practice patterns in general medical and gynecological examinations
- Hormone replacement therapy prescribing patterns
- Gender bias in psychotropic drug prescribing patterns
- Use of EDs by sexually assaulted females

## Annual rate of hospital outpatient department visits for preventive care by sex and patient's age: United States, 2001

## Services ordered or provided for women aged 18-64 years during general medical examination or gynecological examination visits: United States, 1997

- Source: Tao, Zhang, Qian, Services Provided to Nonpregnant Women During
- General Medical and Gynecological Examinations in the United States.
*Am J Prev *Med.21(4): 291-297. 2001.

## Trends in estrogen/progestin drug mention rates at physician office visits by patient’s age:  United States,                        1995-2002

- 65 years and over1

- 45-64 years

- Number of drug mentions per 100 females.

- Increasing trend is significant (p<0.05).

- NOTE:  Rates based on visits made by females.

## Summary

- The NAMCS/NHAMCS are important tools for policy research on outpatient practice
- Nationally representative sampling strategies
- Data based on either physician/hospital self-report or medical record abstraction by interviewers
- NAMCS/NHAMCS and women’s health
- Understand health care practice
- Examine quality of care
- Track changes in utilization