The importance of meeting blood spot card transit standard times

The NSU is working with the screening lab and DHBs to improve transit times.
The NSU is working with the screening lab and DHBs to improve transit times.
The National Screening Unit (NSU) would like to remind practitioners how important it is for blood spot cards (Guthrie cards) to meet the transit time for reaching the laboratory for testing. The transit time is the time taken for cards to reach the laboratory from the date the blood sample was taken – with an expected standard of four days or less.

The laboratory tests the blood spots for over 20 metabolic disorders as part of the Newborn Metabolic Screening Programme (NMSP).

Even with the introduction of the supply of FastPost envelopes to practitioners in 2010, there is still room for improvement, with data showing 70 percent of cards from around New Zealand are reaching the laboratory within four days. The standard is 95 percent. The percentage of samples meeting the standard varies significantly between DHBs, from 90 percent to 50 percent.

For the approximately 45 babies who are diagnosed every year through the programme, an early result and treatment leads to reduced morbidity and mortality. These benefits can only occur if blood spot cards reach the laboratory in a timely manner.

The NSU is working with the screening laboratory and DHBs to improve transit times. National and local initiatives include:

  • testing NZ Post systems
  • testing internal DHB mailing systems
  • contacting practitioners whose samples are taking longer than 15 days to reach the laboratory
  • talking with DHB staff about processes to gain a better understanding of who is taking samples, how they are processed and how they enter the postal system
  • providing data to DHBs on newborns within their domicile.

These initiatives have shown there are transit delays when using internal DHB mail systems. As a result, some DHBs have changed their practice – for example, assigning a person to take the samples to a FastPost mailbox every day or using courier services.

The NZ Post system is not the reason for delays, in fact, FastPost performs better than other postal systems and posting samples as soon as they are dry into a FastPost box prior to the collection time will lead to improved transit times.

The issue affects samples taken within DHBs and in the community.

The key messages for practitioners and DHBs are:

  • perform the heel prick at 48 hours of age or as soon as possible after this, taking into account sample drying takes about two hours
  • post the sample as soon as it is dry
  • use the FastPost envelope provided by the NMSP
  • post the sample in a FastPost box (it is worth checking the daily collection time to ensure samples are posted before this time)
  • avoid internal DHB mailing systems
  • check that a screening result is received within 7-10 days of taking the sample.  

Thank you to all those who have given their time to provide advice and support to improve transit times. We welcome any further suggestions or comments by email: [email protected]

For further practitioner information on the NMSP, please see the Guidelines for practitioners on the NSU website. If you require more lancets, blood spot cards or FastPost envelopes, please email [email protected].

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Page last updated: 25 February 2015