Overview of the NAMCS and NHAMCS

1. Overview of the NAMCSand NHAMCS Linda McCaig and David Woodwell Ambulatory Care Statistics Branch Division of Health Care Statistics

2. Overview • Background • Data uses • Survey methodology • Current and proposed survey items • User considerations • Methodological studies • Data dissemination • NCHS Research Data Center

4. National probability sample surveys • 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

5. Original NAMCS survey goals • National statistics • Professional education • Health policy formulation • Medical practice management • Quality assurance

6. NAMCS history • Survey began in 1973 • Annual data collection through 1981 (NORC) • Conducted in 1985 (NORC) • Annual began again in 1989(Census)

7. NHAMCS history • Survey began in 1992 • Annual data collection (Census)

8. How are NAMCS and NHAMCS data used?

9. Data uses • Understand health care practice • Examine the quality of care • Track certain conditions • Find health disparities • Measure Healthy People 2010 objectives • Serve as benchmark for states

10. Data users • Over 100 journal publications in last 2 years • Medical associations • Government agencies • Health services researchers • University and medical schools • Broadcast and print media

13. Total Ambulatory Care Visits SOURCE: CDC/NCHS, NAMCS and NHAMCS, 2001.

14. Annual rate of injury-related ED visits for seniors by patient residence

15. Percent of physician office visits by type of cardiac rhythm modifying agent Fang et al. Arch Intern Med 2004;164(1):55-60.

16. Percent of selected ED visit characteristics among released patients who had a blood culture

17. Potentially inappropriate drug prescribing at elderly physician office visits Goulding. Arch Intern Med 2004;164(3):305-312.

18. Number and rate of physician office visits for diabetes Number of visits in millions Rate per 100 persons Grant et al. Arch Intern Med 2004;164(10):1134-1139.

19. Annual rate of injury-related ED visits for children by diagnosis Head wound Other wound Intracranial Poisoning

20. Variations in drug mention rates for selected therapeutic classes by source of payment

21. Variations in drug mention rates for selected therapeutic classes by MSA status

22. HP2010 Objectives on antibiotic prescribing

23. NAMCS and NHAMCS Methodology

24. NAMCS Scope • Includes non-federal, office-based physicians • Excludes physicians whose main activity is teaching, research, administration, hospital-based care, or who are unclassified as to activity and those in certain specialties

25. In-Scope NAMCS locations • Freestanding clinic/urgicenter • Federally qualified health center • Neighborhood and mental health centers • Non-federal government clinic • Family planning clinic • HMO • Faculty practice plan • Private solo or group practice

26. Out-of-Scope NAMCS locations • Hospital EDs and OPDs • Ambulatory surgicenter • Institutional setting (schools, prisons) • Industrial outpatient facility • Federal Government operated clinic • Laser vision surgery

27. 112 geographic PSUs 3,000 physicians 25,000 visits 1 week reporting period NAMCS Sample design

28. NHAMCS Scope • OPD was intended to be parallel to the NAMCS in the hospital setting • General medicine, surgery, pediatrics, ob/gyn, substance abuse, and “other” clinics are in-scope • Ancillary services are out of scope

29. 112 geographic PSUs 500 hospitals 400 EDs and 250 OPDs 37,000 ED and 35,000 OPD visits 4-week reporting period NHAMCS Sample design

30. Gaining cooperation • Advance letters • Endorsement letters • Public relations materials • Conversion of refusal

31. Data collection procedures • Induction visit by Census field representative (FR) • FR training of office/hospital staff • Take every number • Prospective or retrospective method

32. Items collected on Patient Record form (PRF) • Patient characteristics • age, race, sex • Visit characteristics • reason for visit, diagnosis, medication • Provider characteristics • physician specialty, hospital ownership

33. Repeating fields • Reason for visit (3) • Cause of injury (3) • Diagnosis (3) • Ambulatory surgical procedures (2) • Medications (8)

34. Data processing • Data are coded and keyed by Constella Group Inc. (CG) • Quality control procedures • Edit checks by NCHS

35. Coding systems used • A Reason for Visit Classification (NCHS) • ICD-9-CM • diagnoses • external causes of injury • procedures • Drug coding system (NCHS) • National Drug Code Directory

36. NAMCS and NHAMCS 2001-2004 PRFs

37. Patient Record form - common items • Patient’s zip code • Date of visit • Date of birth • Sex • Ethnicity

38. Patient Record form- common items • Race • Source of payment • Reason for visit • Diagnosis

39. Patient Record form –common items • Diagnostic/screening services • Medications and injections • Providers seen • Visit disposition

40. Injury/poisoning/adverse effect items • External cause – narrative text since 1997 • ED • intentionality • work related

41. NAMCS and OPD PRF- unique items • Does patient use tobacco • Counseling/education/therapy • Surgical procedures • Time spent with physician (NAMCS only)

42. 2001-2004 NAMCS and OPD PRFcontinuity of care items • Patient’s primary care physician/provider • Was patient referred for visit • Patient seen before • Seen how many times in past 12 months • Major reason for visit • Episode of care • Other physicians share care

43. ED Patient Record form- unique items • Arrival time • Discharge time • Time seen by physician • Mode of arrival • Immediacy

44. ED Patient Record form- unique items • Presenting level of pain • Alcohol related visit • Work related visit • Procedure checklist

45. ED Patient Record form- continuity of care items • Seen ED within last 72 hours • Episode of care • Initial or followup visit

46. On Time seen by physician Mode of arrival Presenting level of pain Off Visit related to an adverse drug event Recycled items on 2003-04 ED PRF

47. NAMCS and OPD PRF revisions 2005-06 – emphasis on chronic conditions

48. Arthritis Asthma Cancer Cerebrovascular disease CHF Chronic renal failure COPD Depression Diabetes Hyperlipidemia Hypertension Ischemic heart disease Obesity Osteoporosis NAMCS and OPD PRF- new items for 2005-06

49. NAMCS and OPD PRF - new items for 2005-06 • Vital signs • Height • Weight • Temperature • Blood pressure • Disease management program • Medication – new or continued

50. ED PRF- new items for 2005-06 • Homeless • Discharged from any hospital within last 7 days • Medication given in ED or prescribed at discharge • Reason patient was transferred