EHDI Guidance Manual – Chapter 3: Updating and Using Your EHDI-IS for Tracking, Surveillance and Program Improvement

What to know

Your properly constructed EHDI-IS enables tracking and surveillance of children with hearing loss. It provides the data critical to ensuring that every infant and child in your jurisdiction receives hearing screening and that those with hearing loss receive interventions. When your system is in place and fully functional, you can turn your full attention to the use and dissemination of the valuable information it collects – discussed in Chapter 4.

Graphic representation of the manual as a red book.

Chapter Objectives

This chapter will help you to

  • Understand the role of an EHDI-IS and how it supports an EHDI program;
  • Use the EHDI system for tracking and surveillance to document and monitor the hearing status of every baby born in the jurisdiction;
  • Use the EHDI-IS to identify gaps in the data collection process; and
  • Use the EHDI-IS to support program improvement and policy decisions.

Considering updates to your EHDI-IS for tracking, surveillance and program improvement

Most often, your EHDI program will already have an EHDI-IS in some form or fashion, even if it is a "pencil and paper" system that relies on the reporting of screening, diagnostic, and EI reports to the program by mail. When considering the need for updates to your current EHDI-IS, broadly defined as ranging between minor modifications and significant system changes, a well thought out process is recommended in order to assess whether or not it is able to accomplish your intended tasks. It is important to ask questions that reflect on the state of your current EHDI-IS. Does it work as intended? What are its strengths? More importantly, what are its weaknesses? In what ways can it be improved? It is at this point, that the principles of evaluation, as discussed in Chapter 6, become important to consider in relation to the items below.

In this chapter, you will find considerations for your existing EHDI-IS. These considerations are best applied to systems that have data regarding the functionality/attributes of the EHDI-IS. Their purpose is to evaluate the performance of your surveillance system and assess its relative usefulness in accomplishing the aims of your EHDI program with regard to tracking, surveillance, and program improvement.

System usefulness

Here are seven things to think about when considering potential updates or enhancements to your EHDI-IS:

  1. Assess usefulness to determine how beneficial the system has been in enabling the tracking of infants and young children through the EHDI process.
    1. The usefulness of the data collected through the IS can be inferred from how data from a new/modified system better support early identification and follow-up of services that would not be possible without the IS.
  2. Consider the status of your IS’s functionality. Look at where it began and where it is it now.
    1. Is the functionality better or worse? How does the data from the new/modified system support tracking and inferences about follow-up and hearing loss patterns that would not be possible without it.
  3. Use all available tools, such as the EHDI-IS Functional Standards Tool, which allows you to compare your IS's performance to the EHDI-IS Functional Standards.
  4. Attend to your system’s flexibility, its ability to be updated and adapt as changes are needed.
  • While larger changes (e.g., a system change) may require significant effort and resources, in general, updates to the IS should ideally occur with minimal additional time, personnel, or other resources.
    • Do you have access to the raw data?
    • Can you perform analyses on raw data with minimal effort?
    • Do you have the ability to generate new reports with minimal effort (e.g., without having to submit a request to a vendor or your IT department)?
    • Does the IS have the ability to shift from hearing loss tracking to surveillance (explained below)?
    • Can your system meet changing detection needs? Can it
      • Add unique data?
      • Capture other relevant data?
      • Add providers/users to increase capacity?

5. Actively promote your system’s acceptability, which can be inferred from the extent of its adoption. This is reflected by the participation rate of reporting sources, completeness of data reporting, and timeliness of reporting.

  • Have you maximized the sharing of electronic health data with good standardization among the involved electronic data systems?
  • Have you considered/made allowances for jurisdictional law and other policies with regard to reporting and sharing data (e.g., HIPAA, FERPA)?

6. Pay attention to your system’s capacity, stability, and resilience (e.g., update capacity and adjustment to changing data needs) and reliability. Consistently reliable information about the condition under surveillance is an aspect of data quality.

  • Is the IS consistently operating?
  • What is the frequency of outages?
  • What downtime is needed for servicing/updating?
  • What is the downtime for users (program staff as well as end-users)?

7. Determine your system’s sustainability.

  • Is there adequate funding for what you want your system to be able to do?
  • Is the investment of resources for your EHDI-IS commensurate with the relative value of the results/tracking/surveillance it produces?

Being able to demonstrate the usefulness of your system is key to achieving support for your program. This requires monitoring and evaluation, which are discussed in detail in Chapter 6.

You would be well advised to consult the multiple tools available to plan and implement your program's sustainability, some of which are referenced in CDC's health equity resource toolkit. [PDF – 3.77MB]1 (For example, one which addresses estimating a program's public health impact is the RE-AIM [Reach, Effectiveness, Adoption, Implementation, Maintenance] planning and evaluation framework.)

Make use of available CDC tools

EHDI System Self Evaluation Tool (ESSET)

As discussed in Chapter 1, the EHDI Functional Standards provide a framework for determining the operational, programmatic, and technical functional requirements for a complete EHDI-IS.

  • The ESSET is a self-assessment tool that helps you identify the strengths and weaknesses of your EHDI-IS. The tool is NOT intended to be used as a roadmap in that it does not tell you where to start or what to do. Rather, it enables you to evaluate your EHDI-IS as it relates to the Functional Standards.
  • Evaluation of your IS program is discussed in Chapter 6 and a thorough discussion of public health surveillance, including its evaluation framework, can be found here.2 Although this paper addresses disease outbreaks, it is just as applicable to EHDI programs.

Realizing the potential of your EHDI-IS

Once built and implemented, the EHDI-IS can be a powerful tool as you collect and then begin to use the screening, diagnostic and early intervention data that is now available. With proper planning and foresight, your system can help you in your work to serve infants and families, in tracking and surveillance and in the quality assurance and program improvement described in Chapter 6.

Tracking and surveillance

What is the difference between tracking and surveillance?

  • Tracking is often thought of as following a group to document events or outcomes of interest. In the EHDI program, infants are tracked from screening through referral to early intervention. If infants are not tracked accurately, they may be lost to follow-up, or their information may be missing in the program (loss to documentation).
  • "Surveillance is often defined as the ongoing, systematic collection, analysis, and interpretation of data."3 The EHDI-IS is a mechanism to enable states to capture information on live, occurrent births that should have received a newborn hearing screening and received follow-up services if needed. The data collected in the system can be used to guide the activities of your public health program, describing patterns related to hearing loss, diagnostics, early intervention, and loss to follow-up/loss to documentation-related issues. Results from the data analysis can be used to make improvements in the EHDI-IS, the state data collection procedures, and/or inform state-based policies. Additionally, EHDI surveillance data can be used to monitor progress toward the achievement of national priorities, including the EHDI 1-3-6 benchmarks and the Healthy People objectives.

What is the difference between active and passive surveillance?

  • Active surveillance means that the organization/program conducting surveillance initiates procedures to get reports. It occurs when healthcare workers or public health officers proactively collect data on patients or participants from the general public. In general, a search is conducted to find cases.
  • Passive surveillance means that the organization/program does not contact potential reporters (healthcare workers, public health officials, etc.), but instead waits for the reports to be submitted to them.


There is no way to investigate problems, identify their causes, and implement control measures if they are not detected. That is the rationale for tracking and surveillance. And, once hearing loss is detected through screening and diagnosis and addressed through early intervention, tracking continues to monitor the effects of a particular intervention or prevention program on the prevalence of hearing loss and use of special education services over time.

So, the effectiveness of your EHDI program is dependent on your ability to track the population for which you are responsible. Your EHDI-IS can support your program by serving as the tool that enables you to track all occurrent births in your jurisdiction and promote the infants' receipt of

  • Screening before 1 month. And if necessary,
  • Diagnostic assessment before 3 months. And if necessary,
  • Enrollment in early intervention before 6 months.

For EHDI-IS to be usable to support program improvement and policy decisions, it will be important to capture the information above as described in Chapter 2. Clearly defined data elements will be necessary.

  • The Joint Committee on Infant Hearing (JCIH) recognized the need for standardization of definitions and data reporting, and recommended "the development of uniform state registries and national information databases incorporating standardized methodology, reporting and system evaluation". The JCIH also expressed the need for federal and state agencies to standardize data definitions to ensure the value of state registries and federal data sets, and to prevent misleading or unreliable information. The adoption of standardized data definitions and reporting practices can help public health officials to better evaluate the delivery of recommended hearing-related services, to generate more accurate data, and to assess actual progress towards national goals.
  • By implementing the EHDI Functional Standards and clearly defined data definitions, your system should enable you to track all infants through the EHDI process.

What is the difference between "loss to follow-up" and "loss to documentation"?

Ideally, ensuring that all infants receive recommended follow-up screening, diagnostic, and intervention services is a key part of every EHDI program's mission. Being able to accurately assess and monitor how many infants are and are not receiving follow-up services is an important part of accomplishing this mission, which is why loss to follow-up (LFU) and loss to documentation (LTD) rates are relevant metrics for programs.

  • There are multiple ways to calculate and report rates of LFU/LTD and, depending on the definitions and formulas used, the rates can vary widely and represent different aspects of LFU/LTD. Jurisdictions can consider what, if any, other definitions of LFU/LTD may be beneficial to use for their own tracking and surveillance activities.
    • There are multiple definitions, each with their own advantages and disadvantages. Consider carefully these advantages and disadvantages when using alternate definitions.
    • Ideally, your EHDI-IS will enable programs to calculate rates using different data definitions when needed by the program.
  • CDC has developed a standard definition and formula for reporting and calculating national rates of LFU/LTD that are used for the annual Hearing Screening and Follow-up Survey (HSFS). Infants reported in any one of the following three categories are considered to be LFU/LTD: unable to contact the family, the family was contacted but unresponsive, or reason unknown.
    • The formula used by CDC for LFU / LTD for Diagnosis is: # LFU/LTD (#Unable to Contact + #Unresponsive + #Unknown) / Total Not Pass * 100
    • The formula used by CDC for LFU / LTD for Intervention is: # LFU/LTD (#Unable to Contact + #Unresponsive + #Unknown) / Total w. Permanent Hearing Loss * 100

When analyzing and reporting data about LFU/LTD, the definition(s) and formula(s) being used to calculate LFU/LTD clearly state what the rates represent. The results of using different definitions are illustrated in this fictional example adapted from the article Importance and Progress in the Standardization of the Reporting and Analysis of EHDI Data.4

Table 1. Adopting Different Definitions of Loss to Follow-Up/Loss to Documentation

Total Not Pass = 800


In process




Moved out of jurisdiction


Medical reason


Physician did not refer


Infant died


Parents / family declined


Parents contacted but unresponsive


Unable to contact




Percentage of LFU/LTD, according to the CDC

39.1% or (295+4+14)/800

(Equation 1)

Percentage of LFU/LTD, according to Jurisdiction A

48.1% or (5+29+15+0+1+22+295+4+14)/800

(Equation 2)

Percentage of LFU/LTD, according to Jurisdiction B

2.3% or (4+14)/800

(Equation 3)

Table 1 reflects variation in calculating LFU/LTD for diagnosis, using a hypothetical cohort of 800 infants who did not pass the hearing screening and needed a diagnostic evaluation. For this scenario, according to the CDC guidance, the LFU/LTD for diagnosis would be 39.1% (Equation 1). Jurisdiction A, however, may calculate and report LFU/LTD differently in their reports and include all reasons except infant death, arriving at 48.1% (Equation 2). In contrast, Jurisdiction B may exclude from the LFU/LTD category infants whose families were unresponsive. This would bring their LFU/LTD estimate to 2.3% (Equation 3), an underestimate in comparison to the CDC’s formula of 39.1%. If each of these different rates is reported without stating what definition is being used, it will be unclear what the rates actually mean.

In process for diagnostic testing

However, some infants are not "lost," but rather are considered "In Process." In 2008 CDC revised the definition of the In Process category to specifically include only infants who had been seen by an audiologist at least once and who had a follow-up appointment already scheduled. An explanation of the definitions involved in the 2014 CDC EHDI HSFS can be found on the EHDI HSFS Explanations [PDF – 524 KB] document, with "In Process" described on page 10.5

"In Process" refers only to infants who

  1. Did not pass a hearing screening;
  2. Have been seen by an audiologist or other approved provider; and
  3. Do not yet have a diagnosis.
  • If an infant has not been seen by an audiologist or other approved provider within 6 months of the last appointment for diagnostic testing and still does not have a documented diagnosis, they should be reported in the "Unknown" or other appropriate "No Documented Diagnosis / Undetermined" category.
  • If an infant has received a documented diagnosis of either hearing loss or no hearing loss, they should not be reported as being "In Process."

The number of infants reported as being In Process ought to be small, as this should be a relatively rare event.

Additional "In Process" concepts in the EHDI HSFS Explanation document to consider include:

  • Only scheduling an appointment for an initial diagnostic evaluation or making a referral to an audiologist or clinic is not considered "In Process" and should not be reported in this field.
  • If a case is considered "Open" by the respondent that does not automatically mean that it should be reported as "In Process." Cases considered as "Open" should only be reported as being "In Process" if they meet the above stated criteria for this field.
  • If an infant has actually been seen by an audiologist and a permanent hearing loss has been established, it should be reported in the appropriate "Total Hearing Loss" field.
  • If a permanent hearing loss has been diagnosed but the degree has not been determined, the HSFS guidance document states that the case should not be reported as "In Process" for the purposes of the EHDI survey.

Case closed

  • Although this data category is not a CDC standard field, several states have used this data field to capture data on some infants who are categorized as lost to follow-up or lost to contact, or who have moved out of the jurisdiction.
  • The definition varies by state. In some states, closed cases and lost to follow-up cases are identified in separate data fields. In other states, closed cases are considered a subset of lost to follow-up.

Both options, "In Process" and "Case Closed," can complicate the accurate assessment of EHDI program effectiveness and performance if care is not taken to clearly define what your jurisdiction intends to measure.

Handling "transfers"

Some infants are transferred from their birth hospital to another hospital for additional/extended care. Optimally, an infant is screened for hearing loss just prior to discharge and going home. State-based EHDI programs can track infants who have been transferred in order to ensure that they also undergo hearing screening.

The EHDI-IS Functional Standards contain information and recommendations for configuring your EHDI-IS to handle tracking of infants transferred from their birth hospital to another hospital for additional/extended care.


Your EHDI-IS can enable you to conduct surveillance of the newborn population in your jurisdiction.

Surveillance goes beyond mere tracking. It is the active, systematic collection (this is why Chapter 2 is important), analysis, and interpretation of data about selected health conditions, closely integrated with the timely dissemination of results to providers and other stakeholders in the EHDI process.

  • In the case of EHDI, the goal is early identification of hearing loss in order to lessen the effects on the newborn.
  • Surveillance programs typically use a variety of data sources to provide a complete understanding of a particular disease in the community and insight into its control.

At a minimum, your EHDI-IS ought to be able to capture the individual level data needed to conduct active follow-up on the screening, diagnostic assessment and early intervention enrollment done. In addition to documenting the receipt of services, it can be beneficial for your EHDI-IS to include data regarding early intervention outcomes. The availability of data about outcomes among deaf and hard of hearing (D/HH) infants can make it possible to conduct additional surveillance that can support

  • Evidence-based interventions;
  • Data-driven policy decisions and/or changes; and
  • Assessment of your EHDI program's impact.
  • For example, outcomes data can address the question "How are D/HH children identified and enrolled in early intervention performing compared to children without hearing loss?"

A more thorough discussion of data use and dissemination is found in Chapter 4 of this Guidance Manual.

EHDI-IS support of programmatic decision making

Your EHDI-IS can assist with programmatic decision-making (i.e., evaluation and program improvement).

Data-driven programmatic decision-making can help you to know if your EHDI program is serving its intended purpose. But data collection can do more than just support tracking and follow-up of infants in your jurisdiction. It can also support program improvement.

  • It can help you formulate and set health priorities;
  • It can assist with planning, implementing, monitoring, managing, and evaluating your program (as discussed in Chapter 6).

In order to make good data-driven decisions for your EHDI program, you will need to use the epidemiologic, economic, demographic, and other types of information that you collect from multiple sources, combined with your EHDI-IS data. At its most basic, you will need to measure the "problem" and the result of the intervention (again, see Chapter 6's discussion of Evaluation).

In making data-driven decisions, you will need to

  • Define your priorities and focus your data collection and analysis on these priorities. Make sure you understand what you hope to accomplish with your EHDI-IS. How can you best achieve your EHDI 1-3-6 benchmarks?
  • Invest effort into obtaining quality data.
  • Use the power of integrated databases, such as Vital Records and Part C Early Intervention. For example, integrating with Vital Records will enable a state EHDI program to ensure that all occurrent births are accounted for in the screening at birth hospitals.
  • Commit to rigorous data analysis to discover, diagnose, and explain problems. This will enable you to assess the following
    • Contributing factors;
    • Affected communities; and
    • Trends over time (Is the implementation of a solution effective?)

Importantly, consider a plan for disseminating your data findings and conclusions to advisory boards and other stakeholders. They can use your data to help with future planning and priority setting.

The importance of data sharing and reporting

Currently, most state EHDI programs routinely exchange information with hospitals, physicians, and audiologists. However, the collaboration between EHDI programs and early intervention services is not as consistent. An important role of the state EHDI program staff is to work collaboratively with medical professionals, audiology centers, and early intervention providers to establish a mechanism for data exchange.

Effective collaboration between partners can ensure that

  • Infants receive recommended services in a timely manner;
  • Information management is improved and support is provided to families; and
  • Evaluation of the effectiveness of services to children is maximized.

The loss-to-follow-up/loss-to-documentation rates can be greatly improved when providers report relevant data with standardized definitions to the state EHDI program. An established protocol for data exchange is essential to tracking and surveillance, and to determine the developmental outcomes for children who are deaf and hard of hearing.

The EHDI Advisory Committee may be helpful in generating ideas and developing memoranda of understanding or agreement (MOU/MOA), data exchange agreements, universal referrals and forms, and additional documents to facilitate the exchange of data.

Collaborate, collaborate, collaborate

Effective tracking and surveillance activities, to ensure the health and wellbeing of infants in your jurisdiction and to make the best data-driven decisions for program improvement, will often require additional data from other sources in your state. Implementation of electronic health records interoperability standards and technologies may be necessary, and suggests a need to be familiar with health information technology (HIT). These and other considerations are discussed in Chapter 7.

Linking with Other Systems to Collect Additional Data

Some of the data collected on newborns are duplicated because all reports include demographics of the infant and locator information for parents and pediatricians. Most state health departments receive the following information on each newborn.

  1. Birth certificate
    1. Pro: Includes information on birth defects, which is important as some birth defects are risk factors for progressive hearing loss.
    2. Con: Assigned days or even weeks after birth.
    3. Con: Birth certificate number is not used in the health record in many states.
  2. Metabolic (blood spot) screening results
    1. Pro: Since this number is assigned soon after birth, some state health departments have proposed to use this as a linking number for infant hearing reporting.
  3. Infant hearing screening results.

If the state health department has separate data reporting systems for the three data sources above, then one approach could be to try to link all the systems' records for each child. For example, if the state knows a child's birth certificate number and blood spot card number, then any data associated with either of these identifiers can be linked via a separate system to query and retrieve those disparate data. While there are well-known problems with linking data records (e.g., the names of the child and mother might change, or the date of birth might be missing or incorrect), this dynamic linkage of records could enable an integrated view of the child's medical history and provision of the composite information to healthcare providers.

Unique identifier(s) to link records and track each child

To track children over time efficiently and minimize errors, state health departments need a way to identify each child uniquely.

Some states have created a unique number for each child to facilitate data linkage. A set of labels with a unique number and bar code are printed on a page and the labels are assigned to each infant at birth. One of those labels is placed on each of the data report forms (metabolic screening, infant hearing screening, and birth certificate) for each patient, or the number is entered on an electronic report form. At the state health department, the data from the different report forms for each child are linked together using this unique identifier.

The problem is that most state health departments do not have such a set of identifiers for each child in a single database. A simple way to create such a set of identifiers for record linkage and infant tracking is to include these identifiers as part of the electronic birth certificate reporting. The following identifiers are recommended

  • Birth certificate number;
  • Blood spot card number;
  • Infant's birth hospital and medical record number;
  • Mother's medical record number; and
  • Newborn hearing screening test report number (if hearing test results are reported to the state health department independent of the electronic birth certificate or blood spot card).

Integration for data systems: master child index and "child profile"

Some states are planning to develop integrated online systems that will enable hospitals and healthcare providers to report and receive information in a uniform way based on the child, rather than the type of service provided. An integrated data system for newborns would include all the information shown on birth certificates, metabolic screening and hearing screening reports, as well as other information on health conditions and prevention services such as birth defects and immunizations. In an integrated system, it would be possible to have an up-to-date summary of health status and services received for each child. Such a summary, or "child profile," is what healthcare providers and case managers need to care for each child.

Of course, such integration has patient privacy implications and is subject to laws governing protected health information. These issues are discussed in great detail in Chapter 5.

There are many advantages of having an integrated online system, including

  • For hospitals and healthcare providers:
    • Less burden because of less duplication of data reported and a more uniform method of reporting;
    • Better healthcare delivery to patients because more accurate and more comprehensive data on each child are reported to the state health department; and
    • Potential of automating the reporting process by interfacing with the hospital information system.
  • For the state health department:
    • More timely data on each child;
    • Less burden on data capture, entry and validation;
    • Less chance of duplication or wrong information on a child because of mistaken identity;
    • Less burden in finding and locating children and families because different programs can share and update relevant information, and fewer infants and children will be "lost to follow-up"; and
    • Better healthcare delivery to infants because important information (such as risk factors) collected by one program can be used by another for case management.

Child-based integrated reminder system

Another benefit of an “integrated” data system (using an integrated database or dynamic linkage) is that it allows for an integrated reminder system. Instead of receiving numerous reminder messages about different healthcare needs, healthcare professionals and parents could be notified of hearing test, immunization, and other health services that the child needs—all in a single message.

Content Source:
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  2. Buehler JW, Hopkins RS, Overhage JM, Sosin DM, Tong V. (2007). Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks. MMWR, 53(RR05);1-11 Available at
  3. Thacker SB, Berkelman RL. History of public health surveillance. In: Halperin W, Baker EL (Eds.) Public Health Surveillance. New York: Van Norstrand Reinhold; 1992.
  4. Suhana A, Satterfield A, Mason CA. Importance and Progress in the Standardization of the Reporting and Analysis of EHDI Data. J Early Hear Detect Interv. 2016;1(2):2-7. PMCID: PMC5102258
  5. 2014 CDC EHDI Hearing Screening and Follow-up Survey (HSFS): Explanations [PDF – 524 KB]