Online Program

Coding system: A source of variability in reported prevalence rates of atrial septal defect

Monday, November 4, 2013

Ha Pham, Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA
Tri Tran, Children's Special Health Servicies, Louisiana Department of Health and Hospital, New Orleans, LA
Background:The variation across states in the ASD prevalence rates may either indicate a true difference or represent an artifact of case identification.Evaluation of the coding system by which cases are identified is necessary to provide insight awareness in a comparison of ASD prevalence rates across states.Objectives:Determine whether use of different coding systems in birth defects surveillance systems influenced ASD prevalence rates,and whether effect of coding systems on ASD prevalence rate was different between case ascertainment methods.Methods:Data from 2012 Population-Based Birth Defects Surveillance Programs Report,including 2005-2009 data of 35 states,were analyzed.Poisson regression was used to examine the association of prevalence rate of ASD with coding systems adjusting for other covariates.An interaction term between coding systems and case ascertainment methods was evaluated in multiple regression models. Results:The two-fold higher ASD prevalence rates for states using ICD-9-CM including PFO compared to those using CDC or ICD-9-CM excluding PFO was observed.Furthermore,compared to the states using CDC or ICD-9-CM excluding PFO,the rates of ASD were approximately three times higher for those using ICD-9-CM including PFO where either the passive ascertainment method or combined ascertainment method was applied(prevalence ratio[PR]3.26;95%CI 2.87,3.70;and PR 2.78;95%CI 2.71,2.85;respectively).However the rate was found slightly lower in a same comparison across states where the active ascertainment method was applied (PR 0.87;95%CI 0.80,0.94).Conclusions:The ASD prevalence rates across states significantly vary according to the type of coding system used.Moreover,this variation is further modified based on the type of case ascertainment method employed.Careful consideration should be given to a comparison of ASD prevalence rates across states.

Learning Areas:

Conduct evaluation related to programs, research, and other areas of practice
Public health or related laws, regulations, standards, or guidelines
Public health or related research

Learning Objectives:
Compare a wide range of the reported Atrial Septal Defect (ASD) prevalence rates across states Identify coding system as a primary factor that led misleading gap in the reported prevalence rates of ASD

Keyword(s): Birth Defects, Children's Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been the principal or co-principal on the quality control for reporting system of birth defects surveillance programs. Among my scientific interests has been the development of strategies for improving reporting system of state-based birth defects surveillance systems.
Any relevant financial relationships? Yes

Name of Organization Clinical/Research Area Type of relationship
Louisiana Department of Health and Hospital Children Special Health Services Work as an intern

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.