Overview Of The National Health Care Survey (NHCS)

1. Overview Of The National Health Care Survey (NHCS) American Public Health Association 134 Annual Meeting & Exposition November 4, 2006 William S. Pearson, Ph.D. Division of Health Care Statistics Centers for Disease Control and Prevention National Center for Health Statistics

2. National Health Care Survey Basic Components Ambulatory care Hospital & Surgical care Long-term care

3. National Health Care Survey Ambulatory Care • National Ambulatory Medical Care Survey • National Hospital Ambulatory Medical Care Survey • National Hospital Discharge Survey • National Survey of Ambulatory Surgery • National Nursing Home Survey • National Home and Hospice Care Survey Hospital & Surgical Care Long-term Care

4. How are NHCS data used? • To understand health care practice • To identify and track problems • To identify inequalities in the provision of services • To establish national priorities • To serve as comparison points for states • To measure Healthy People objectives

5. NHCS Common Methodology • National probability sample surveys • Complex sample designs • Common definitions, data items, sampling frames • Medical diagnoses • Data collected by Census Bureau • High response rates • Data processed by private contractor

6. Data users-NHCS • Over 150 journal publications in last 2 years • Health professional associations • State and federal policy makers • Health services researchers • Epidemiologists • Universities and medical schools • Broadcast & print media

10. Where are people going for their health care and has the setting changed over the years?

11. Hospital discharge rate, 1980-2003 Source: National Hospital Discharge Survey

12. Average length of hospital stay: 1980-2003 Source: National Hospital Discharge Survey

13. Average length of hospital stay by age: 1970-2000 Source: National Hospital Discharge Survey

14. Trends in ED visit rates by age 65 years and over 22-49 years Number of visits per 100 persons 50-64 years NOTE: All trends shown are significant (p<0.05).

15. Percent of live hospital discharges transferred to LTC institutions: United States, 1985-2000 19.1 17.7 14.0 12.4 4.5 3.6 2.0 2.4 Note: Percentages exclude deaths and unknown disposition Source: NCHS/CDC: National Hospital Discharge Survey

16. Percent of nursing home residents admitted from hospital: United States, 1985-1999 Source: NCHS/CDC: National Nursing Home Surveys

17. NHCS strengths • Amount of utilization • Health care users • Sentinel events • Treatment patterns • Trends over time • Springboard for further research

18. NHCS limitations • Few outcome measures • Longitudinal purposes • Episode of illness • Community measures • Rare event estimation

19. Key concepts • Encounter vs. person data • Incidence & prevalence • Utilization rates • National and regional estimate

20. NAMCS and NHAMCS • National Ambulatory Medical Care Survey (NAMCS) • Patient visits to non-federal, office-based physicians • National Hospital Ambulatory Medical Care Survey (NHAMCS) • Patient visits to EDs and OPDs of non-federal, short-stay hospitals

21. History of NAMCS • Planning began in 1967 • Survey began in 1973 • Fielded 1973-1981, 1985, 1989-present • Database covering 30 years

22. History of NHAMCS • Planning began in 1976 • Survey began in 1992 • Fielded annually • 14th year of operation

23. NAMCS and NHAMCS Methodology

24. NAMCS Sample Design • Three stage design (1) 112 PSUs (2) Physician practices within PSUs (3) Patient visits within practices • One-week reporting period • For 2003-- 3,000 doctors sampled; data collected for 25,288 office visits

25. Scope of the NAMCS • Basic unit of sampling is the physician-patient visit • Physicians must be: • Classified by AMA or AOA as primarily engaged in office-based patient care • nonfederally employed • not in anesthesiology, radiology, or pathology • Starting in 2006: • Community Health Centers • Physicians & mid-level providers

26. In-Scope NAMCS Locations • Private solo or group practice • Freestanding clinic/urgicenter (not part of a hospital outpatient department) • Community Health Center (e.g., Federally Qualified Health Center (FQHC), federally funded clinics or 'look alike' clinics • Mental health center • Non-federal government clinic (e.g., state, county, city, maternal and child health etc.) • Family planning clinic (including Planned Parenthood) • Health maintenance organization or other prepaid practice (e.g., Kaiser Permanete) • Faculty practice plan

27. Out-of-Scope NAMCS Locations • Hospital ED’s and OPD’s • Ambulatory surgicenter • Institutional setting (schools, prisons) • Industrial outpatient facility • Federal Government operated clinic • Laser vision surgery

28. NHAMCS Sample Design • Multistage probability design (1) First stage sample of 112 PSUs (2) Hospitals within PSUs (3) Clinics within OPDs, ESA within EDs (4) Patient visits within clinics, ESAs • 4-week reporting period • 546 hospitals sampled in 2003; 40,253 ED visits and 33,492 OPD visits

29. Scope of the NHAMCS • Basic unit of sampling is patient visit • Emergency and outpatient departments of noninstitutional general and short-stay hospitals • Not Federal, military, or Veterans Administration facilities • Located in 50 states and D.C.

30. Data Collection • Bureau of the Census is our field agent • Introductory letter sent 2-3 months in advance of reporting period • Induction interview to train staff, obtain data on practice or facility characteristics • Physician’s office/hospital staff is responsible for completion of Patient Record forms • Census abstracts as a last resort

31. Data Items • Patient characteristics • Age, sex, race, ethnicity • Visit characteristics • Source of payment, continuity of care, reason for visit, diagnosis, treatment • Provider characteristics • Physician specialty, hospital ownership… • Drug characteristics added in 1980

32. Coding Systems Used • Reason for Visit Classification (NCHS) • Drug Classification System (NCHS) • National Drug Code Directory • ICD-9-CM • diagnoses • causes of injury • procedures

33. Drug Data in NAMCS/ NHAMCS • Respondents can list up to 8 medications (including Rx and OTC medications, immunizations, allergy shots, anesthetics, and dietary supplements) that were ordered, supplied, administered, or continued during the visit. • Each entry is called a drug mention. Visits with one or more drug mentions are called drug visits. • Respondents are asked to report trade names or generic names only (not dosage, administration, or regimen). Can’t link drugs with diagnosis.

34. Drug Characteristics • Generic Name (for single ingredient drugs) • Prescription Status – Rx or OTC • Composition Status – single or multiple ingredient • Controlled Substance Status – DEA schedule • NDC Therapeutic Class (4-digit) • Up to 5 Ingredients (for multiple ingredient drugs)

35. Analyzing Drugs • NAMCS or NHAMCS drug data can be analyzed • at the visit level (for example, the number of visits at which a particular drug was prescribed) • or at the medication level (for example, the number of “mentions” of a particular drug at ambulatory care visits

36. Sample Weight • Each NAMCS record contains a single weight, which we call Patient Visit Weight • Same is true for OPD records and ED records • This weight is used for both visits and drug mentions

37. How to Get the Data

39. Public Use Micro-data Files • Downloadable files • NAMCS, 1973-2003 • NHAMCS, 1992-2003 • CD-ROMs • NAMCS, 1990-2002 • NHAMCS, 1992-2002

40. Enhanced Public Use Files • Masked sample design variables • Allow use of SUDAAN, Stata, etc. • Available for 1993-2003 • SAS input statements, label statements, and format statements (1993-2003) • SPSS and Stata code for 2002, 2003

41. NCHS Research Data Center

42. Advantages of the Research Data Center Gain access to information not available on public use files • Patient: ZIP code linked income, education, etc. • Provider: physician sex and age, board certification, teaching hospital • Geographic: FIPS state and county codes

43. Research Data Center – cont. • Can merge with contextual variables (e.g., ARF, NHIS, Census, NHDS) • Health status level • HMO penetration • Physician and specialist supply • Medicaid reimbursement • Air quality • Percent in poverty

44. Research Data Center • E-mail: rdca@cdc.gov • Website: www.cdc.gov/nchs/r&d/rdc.htm • Call (301) 458-4277

45. For more information: • NCHS website: www.cdc.gov/nchs/nhcs.htm • Call Ambulatory Care Statistics Branch at 301-458-4600 • Information about the NAMCS: Don Cherry or David Woodwell • Information about NHAMCS: Linda McCaig or Kim Middleton

46. National Hospital Discharge Survey(NHDS)and National Survey of Ambulatory Surgery(NSAS)

47. Overview of the National Hospital Discharge Survey(NHDS)

48. NHDS Survey Years • Conducted annually 1965-present: • Latest data available: 2003 • 2004 to be available this Winter

49. NHDS Survey Design Scope and coverage: • Short stay, non-Federal hospitals • ALOS < 30 days • General and children’s general hospitals

50. NHDS Sampling Plan Three stage sampling: 1. Geographic units 2. Hospitals 3. Discharges