Thursday, May 13, 2004 - 11:15 AM
5443

Do It Yourself! The Advantages of a Local Random Digit Dialing Survey of Immunization Coverage

Mark H. Sawyer1, Wendy Wang2, Robert Vryheid2, Michelle Picardal3, Sandy Ross2, K. Michael Peddecord2, Michelle Deguire2, and Kathe Gustafson2. (1) San Diego Immunization Partnership, University of California, San Diego, 9500 Gilman Drive, MC 0927, La Jolla, CA, USA, (2) San Diego Immunization Program, County of San Diego Health and Human Services Agency, PO Box 85222, Mail Stop P511B, 3851 Rosecrans Street, San Diego, CA, USA, (3) San Diego Immunization Partnership, UC San Diego, Community Pediatrics, 9500 Gilman Drive, MC 0927, La Jolla, CA, USA


BACKGROUND:
The Centers for Disease Control National Immunization Program has conducted the National Immunization Survey (NIS) since 1994 to provide standardized immunization coverage rates across the country. To obtain more information on local immunization issues, the County of San Diego Immunization Program conducted its own random digit dialing telephone survey (SD RDD) annually from 1995-2000 and 2002-2003.

OBJECTIVE:
1) Describe the advantages of a local RDD telephone survey on immunizations
2) Examine factors that may account for differences between immunization coverage rates determined by NIS and a local RDD survey.

METHOD:
The County of San Diego conducted annual RDD telephone surveys between 1995 and 2003 by adapting the CDC NIS methodology. The methodology differed in that SD RDD is 1) conducted over 2 months, 2) accomplished larger sample sizes, 400-902, 3) employed local multilingual surveyors instead of translators 4) obtained higher levels of record verification and 5) included customized KAB questions to drive local interventions.

RESULT:
The immunization coverage rates for San Diego County obtained by NIS and the SD RDD differed in most years. In recent years the SD RDD coverage rates have been consistently higher than NIS rates. Differences in most years exceed those due to sampling error. In 2002 the coverage rate for 2-year-olds receiving 4 DTP:3 polio:1 MMR was 79% in NIS and 85% in SD RDD. Factors that may account for these discrepancies include 1) use of multilingual local surveyors 2) the process for provider verification and 3) possibly sample size. Responses to customized questions were very useful in shaping immunization interventions at the local level.

CONCLUSION:
A locally performed RDD immunization survey may provide a more accurate assessment of coverage rates and allows for the use of customized questions to shape local immunization interventions.

LEARNING OBJECTIVES:
1) Identify the potential advantages of a locally conducted RDD telephone survey on immunizations.
2) Examine possible reasons for variance in rates between NIS and local RDD surveys.

See more of Measuring Immunization Coverage at the Local Level
See more of The 38th National Immunization Conference