remote therapeutic drug monitoring (TDM): how much money can it save?

Volumetric microsampling technology is the next logical step after conventional dried blood spot (DBS). With volumetric microsampling devices, end-users have a simplified method for drawing blood samples for analysis. The sample collection can be self-administered from any location using a simple finger-stick method.

This remote approach supports remote therapeutic drug monitoring, or TDM. Additionally, the transport and storage of remote dried blood microsamples for TDM is generally simpler and less expensive than working with conventional venous blood samples.

Cost Isn't the Only Advantage of Remote TDM

Another advantage of conducting therapeutic drug monitoring remotely is that it improves the patient experience. A simple finger-prick is far less stressful for many patients who may fear the needles and pain associated with venous blood draws. In many cases, sample collection kits can be shipped out to patients at home, so they can follow the instructions and use the supplies in the kits to collect their own samples.

Microsampling devices like the Mitra^® device based on VAMS^® technology, or the hemaPEN^® based on capillary and DBS technology, are designed to deliver dried blood samples. The samples dry in the devices during transit to a lab, so there is no need for cold shipping to preserve the viability of the specimens.

The person sampling at home, or assisting with sampling in a remote location, can simply put the sampled device back into its specimen bag, seal that inside the provided pre-paid mailing envelope, and send it back to the lab via standard mail. When the lab receives the samples, they will process and analyze them using a dried blood spot (DBS) workflow.

In some areas of the world, where travel is simply not possible, remote microsampling technology can significantly improve field research studies and access to healthcare.

These benefits come together in one key focus area: therapeutic drug monitoring.

Therapeutic Drug Monitoring & Remote Specimen Collection

For many patients, frequent blood testing is crucial for monitoring their progress on prescribed medications over time. Therapeutic drug monitoring (TDM) is the continued measurement of specific blood levels at defined intervals to ensure a consistent drug level concentration in a person's bloodstream.

The burden of frequent blood testing (sampling) for TDM is especially difficult when it requires cooperation from children. For example, after children undergo certain procedures, such as renal transplants, their physician must be able to monitor their condition frequently through blood analysis. Frequent blood tests and clinic visits can be stressful for pediatric patients, and burdensome for their families. An at-home sampling approach to routine blood testing can help reduce the burden and stress of follow-up care.

Savings When Using DBS for Therapeutic Drug Monitoring

A December 2016 issue of The Public Library of Science (PLOS), a peer-reviewed international scientific journal, featured a Netherlands cost analysis of the savings potential for using DBS rather than conventional blood testing. The case studies involved recovering children who required TDM. The analysis considered several variables with regard to both patients or family caregivers and labs or medical facilities, such as:

• Travel expenses: transportation, parking
  
  
• Loss of productivity: calculation of journey time, plus time spent at the hospital, versus time spent on home sampling and mailing the samples from a nearby mailbox
  
  
• Healthcare costs: nurse sampling and supplies versus home sampling and supplies
  
  
• Laboratory costs: Comparison of laboratory costs and overhead for clinic-venous samples versus mail-in samples. (Analysis costs were assumed to be similar)
  
  
• Doctor’s follow-up/feedback time would be the same in both scenarios

The travel expense portion included a distance factor of 145 minutes round trip and a total time in the hospital of 45 minutes.

Result of the Comparisons: Remote vs. Hospital Sampling

In the study, the remote (at-home) DBS sampling was calculated to be just 39.4% of the total cost of in-hospital sampling. The study showed that the major contributors to the higher costs of hospital-based sampling were:

• The additional costs of travel for the patients
• Lost productivity for the patients or caregivers
• The nurse’s or phlebotomist's time to draw blood samples

If weekly sampling were required over a six-month period, the total expenditure and lost time differentials would mount up substantially.

Remote TDM: DBS vs. Volumetric Microsampling Devices

The Mitra and hemaPEN devices provide the key benefits of working with dried blood samples, but with a volumetrically accurate and stable dried blood spot that reduces the incidence of poor sample quality and/or the need to re-sample.

Volumetric microsampling technologies eliminate many of the practical challenges associated with dried blood spot (DBS):

• Gather a fixed volume (10, 20 or 30 μl), every time
• Eliminate unnecessary sampling steps
• Track samples from end-user to lab with native bar coding
• Use as a sample collection device in remote/at-home Sample Collection Kits
• Reduce costs, travel, and wait times in hospital - just sample and ship!

Find out more about remote microsampling applications for Therapeutic Drug Monitoring by visiting our Therapeutic Drug Monitoring (TDM) Resource Page:
 

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