NFIRSGram: Data quality

This NFIRSGram highlights internal data quality checks performed by the National Fire Data Center (NFDC) to identify data errors and to assist states and fire departments in fixing them.

Important points

  • Accurate data is essential for organizational decision-making.
  • Data entry errors are common and should be fixed when identified.
  • Regular data quality checks increase information accuracy and ensure that the best overall data is recorded and used.
 
 
 
 
 
 
 

What is as true in a fire department as in a Fortune 500 corporation?

Data drives decision-making.

For the fire service, this data is collected in the National Fire Incident Reporting System (NFIRS). It is critical to make sure the data collected is complete and accurate because this information is used at all levels — from local budget development to the identification of national preparedness initiatives.

Accurate fire incident reports are really important and they can impact your department just as much as the entire United States. When incidents are documented for the NFIRS, there is the potential for data entry errors — mistakes that can alter the intended meaning of the information. Several mistakes across a region may not be significant, but many mistakes in the same region — or worse, across the entire country — can dramatically affect the meaning of the data. The same result occurs when data is generalized, such as the overuse of the codes for unknown, none or other.

Since the goal is to provide the best data possible, the NFDC developed a series of internal data quality reports to identify some of these data errors and assist the states and fire departments in resolving them. Below are three identified trends in the data, along with a brief discussion of each.

Trend High dollar loss

Section G2 of the Basic Module collects information about the estimated dollar losses and values of property and contents. This is a crucial component of data collection since it is an indicator of fire impact within the U.S. It is important to note that these are only estimations, and the best estimate of the fire department is acceptable. Each field allows a dollar value up to $999,999,999.

What the NFDC looks for: Every incident with a dollar loss value greater than $10,000,000.

Issues identified: Extremely high values and negative dollar values.

How to resolve: Data entry should be made carefully and checked to ensure accuracy.

Trend Duplication of information when using plus-one codes

Plus-one codes are codes that the local or state levels can use to record incident information in regionally-specific detail. More information about these codes can be found in this NFIRSGram: The use of plus-one codes.

Since the plus-one (extra character) is not used in national level analyses, it can appear as if there is a duplicate Actions Taken code (Section F) in the Basic Module.

What the NFDC looks for: Plus-one codes that duplicate the NFIRS code or base code. In this case, the base code length for Actions Taken is two characters, e.g., 86 (investigate). This occurs in multiple-coded fields, most often in the Actions Taken section (since up to three actions can be added per incident).

Issues identified: Nearly every example of a duplicate Actions Taken code was due to using a base code and a plus-one code based on the same NFIRS or base code.

Example: The first Actions Taken code is 11 (extinguishment by fire service personnel) and the second Actions Taken code is 112 (extinguishment with Compressed Air Foam System). This will be viewed at the national level as Actions Taken codes 11 and 11.

How to resolve: Refrain from using a plus-one code in the same field along with its base code.

Trend Incorrect building stories

Section I3 of the Structure Fire Module looks at building height (i.e., the number of stories above and below grade). This data element is required within the Structure Fire Module.

What the NFDC looks for: Stories greater than 30 above grade and greater than five below grade.

Issues identified: Unusually high values for both above grade and below grade stories.

How to resolve: Data entry should be made carefully and checked to ensure accuracy.

Have questions about how to improve the quality of your NFIRS data? Please contact the NFIRS Support Center: Monday – Friday between 8 a.m. – 4:30 p.m. ET, at 888-382-3827 or by email at fema-nfirshelp@fema.dhs.gov.