Monday, July 21, 2014

Limitations of e-Prescribing Standards

The following is an important guest post from Dr. Marvin Harper, CMIO at Boston Children's Hospital, identifying a gap in e-prescribing standards:

Why am I guest writing a blog post here?   As a practicing pediatrician and CMIO at Boston Children’s Hospital I am particularly sensitive to specific limitations of current e-prescribing standards.

Being able to write and route prescriptions electronically provides many advantages over the handwritten paper prescription process that inherently uses families as couriers.  Nonetheless the current standards for e-prescribing have created a void that permits limitations in certified vendor software on both the prescribing and pharmacy receiving side. The result is that our patients are not yet benefiting from the full potential of eprescribing. Additional national standards for electronic prescription transmission are needed to provide the common ground needed by software vendors at each stage of the prescription life cycle.

The core elements to consider when writing a prescription are the name of the medication, the dose form (e.g., capsules, tablets, extended release tablets, liquids), the amount of medication the patient should take at each dose, the dose frequency (e.g., once, twice or three times per day) and the duration of time for the patient to take this medication.

Currently there are no standards for provision, transmission, receipt or display of weight within electronic prescriptions. To prescribe the correct quantity per dose of the desired medication the weight based dose is converted to a finite dose using a recent, appropriate, and reliable patient weight.  This is then converted to an appropriate drug volume dose (e.g., one tablet, five milliliters) based on the drug product selected (e.g. amoxicillin 500 mg capsule or amoxicillin 250 mg/5 mL suspension).  Considering all of these manipulations, it is then obvious that in order for a pharmacist to review and verify that the correct dose is being dispensed, in addition to the medication and finite dose, the pharmacist needs to have the prescriber’s target weight based dose and the patient weight available at the time of review.   Stated another way, providing the weight is not fully sufficient for the pharmacist to verify the intended target weight based dose. With today’s standard the pharmacist only gets a volumetric dose  (e.g., 5 mL) which is then inferred into a strength dose (e.g., mg/kg) from the prescribed formulation. It is therefore impossible for a pharmacist to fully verify that prescribed doses are appropriate for their pediatric patients.

The current limitation for the entire prescription sig line within a prescription to be transmitted electronically is 140 characters.  Basically a tweet.  Not close to enough for many prescriptions.  As a result we must continue to provide some prescriptions on paper to the patient.

Many commonly prescribed medications require slowly increasing or decreasing the finite dose. These are commonly referred to as medication titrations or tapers and are therapeutically very important to avoid secondary complications.  It can be complex to transfer this information satisfactorily to patients and the pharmacist in the best of circumstances.  It is impossible with a 140 character limit to the sig.  In my experience within pediatrics this is most problematic for prescribing anticonvulsants, steroids, and immunosuppressive medications.

Did I mention the current limitation for the sig line within a prescription to be transmitted electronically is 140 characters.  Basically a tweet.  Not close to enough.  It is not possible to provide a compounding recipe within 140 characters.  Why do we need to write prescriptions for compounded medications? Not all patients can take medications in the dose forms available domestically from pharmaceutical companies.  As a result some medications must be compounded (typically crushed and mixed with other ingredients).  In pediatrics, compounding is most often required to make the medication available in a liquid form for patients unable to swallow a pill. This may also apply to adults, especially those needing to receive medications via feeding tubes.  Occasionally medications must be compounded for other reasons such as palatability or patient allergies.

As uses of medications expand beyond traditional indications, in order for a pharmacist to truly review and verify a prescription order, in addition to mathematical checking, it is critical for a pharmacist to know what the medication is being used for to ensure that the prescribed dose is within the recommended range for any particular indication.  Different indications often require vastly different doses of a medication.

Access to known allergies the patient may have to medications and increasingly access to patient genetic information relating to drug metabolism or adverse reactions can help assure that patients receive the safest medications and doses.

In summary it is important that additional standards for expected eprescribe capabilities are defined for vendors providing prescription writing software, the transmission of prescriptions and the software utilized by pharmacists receiving prescriptions. Most importantly, in my mind, are capabilities to transmit the weight, target weight based dose and more space for the electronic sig to accommodate information needed for medication tapers and compounding.


Chris Longhurst said...

Well said Dr. Harper. This is a huge safety and workflow issue for pediatric prescriptions, and needs to be addressed to improve healthcare for all children.

Laura Topor (NCPDP Sig Task Group Leader) said...

Thank you Dr. Harper. Many of the elements that you identify are available in NCPDP's SCRIPT v 10.6, which is the standard that the industry is primarily using (it is the CMS-named standard for e-prescribing. That said, users need to work with their vendors to ensure that the elements (like weight) and the Structured Sig segment are available for use and transmission. Interested parties should contact NCPDP ( for more information.

Michael Burger said...

There are several factors in play. The standards are largely in place, as Laura Topor points out. In order for those standards to be utilized, the EHR on the prescriber side needs to be updated to utilize the standards. At the same time, the pharmacy information system software on the pharmacy side also needs to be updated to utilize the data that has been received from the prescriber. The design concept of most ePrescribing applications today is to mimic the minimum required data for a paper prescription. Now that ePrescribing has passed the "tipping point" where more prescriptions are written electronically than on paper, the time is right for innovation to take ePrescribing to the next level. Making data fields such as patient weight and structured SIG "REQUIRED" versus optional as they are today will go a long way to achieving safer ePrescribing, but it takes consensus among all of the stakeholders to make that happen.

Sharon Wentz said...

Thank you Dr. Harper. I would like to add that this is critical for those of us administering medications. We need to see the weight in kg on the label in order to do a recalculation prior to administration. The character limitations can lead to a devastating medication error, particularly in pediatrics. I was witness to this years ago when working in a critical access hospital with a traveler nurse. The infants weight, and mg/kg were not fully printed out on the label, the nurse administered too much medication. Luckily the infant was ok. Root cause analysis revealed the character limitation. The pharmacy tech could only enter so much information. I agree with Michael Burger-- we have reached a tipping point.

Chris Tonozzi, MD said...

Another important addition to e-precribing is to be able to send stop or discontinuation orders to a pharmacy. When I increase the dose of a med previously prescribed, how can the pharmacist be sure that my new order replaces the old order rather than being an addition to my old order? Or if I send one prescription, and then realize it was incorrect and prescribe another med, how do I get the message to the pharmacist to ignore the first order? With current technology, I can put a comment with the new order, but it would be much clearer if I could stop the incorrect order.