How to Take a Best Possible Medication History

Taking a best possible medication history (BPMH) has been shown to reduce and prevent the incidence of adverse medication events and patient harm. Studies demonstrate that up to 67% of prescription medication histories contain an error. It is for this reason that a BPMH should be taken as soon as practicable once a decision has been made to admit a patient to the hospital.

What is a BPMH?

A BPMH is a list of all current and relevant past medications, including prescription, non-prescription, and complementary, or alternative, medications.

A number of different sources of information may be used to compile the BPMH list, including:

• Patient’s own medication list;
• Patient recollection;
• Patient’s community pharmacy;
• General practitioner;
• Specialist doctor;
• Webster pack;
• Patient’s own medicine packaging;
• Family member or caregiver;
• Nursing home or primary care provider; or
• Previous patient health records.

Patients and carers should be actively involved in providing medicines information, if practical. To further support the medication reconciliation process, patients should also be encouraged to bring their medications in their original containers when being admitted to the hospital, along with a current medicines list.

BPMHs can be conducted either proactively or retroactively. Ideally, a BPMH should be conducted proactively before admission, occurring in the emergency department or the pre-admission clinic. Proactive BPMHs are most beneficial as they can be used to ensure that medicines are charted correctly in the first instance, rather than trying to resolve discrepancies after the patient has been admitted. Retroactive BPMHs are still useful, and should ideally be completed within 24 hours of admission. A retroactive BPMH is completed after the inpatient chart has been written. The resulting BPMH is then compared with the inpatient chart to identify any discrepancies from usual medicine use.

A BPMH is not ‘prescribing’. It is simply documenting an accurate list of the medicines a patient usually takes at home, and how they would take them. The attending prescribers can then consider this list when making prescribing decisions. It is important to note that discrepancies between the charted medicines and the BPMH may, or may not, be intentional. However, identifying discrepancies makes it more likely that unintentional medication changes can be rectified.

How should a BPMH be compiled?

A BPMH can be completed by any healthcare provider including doctors, pharmacists, and nursing staff. When obtaining and documenting a BPMH, a systematic interview approach should be used to ensure that vital pieces of information are not overlooked. For example, a patient may not consider a complementary medicine (such as St John’s wort) as a ‘medication’ since it is not a prescription item. A patient may also need to be prompted to tell you about the Norspan^® patch they are wearing under their shirt, or the glaucoma eye drop they use at night.

There are tools available to assist with approaching a BPMH systematically. The Medication Management Plan (MMP), for example, includes a check box list of possible medicines a patient may take (Figure 1). Running through a thorough list such as this with a patient can help to identify medicines that may be overlooked, such as inhalers or sleeping aids.

Figure 1. Medication Management Plan Checklist (reproduced with permission from the Australian Commission on Safety and Quality in Health Care)

 A suggested interview structure for compiling a BPMH is as follows:

1. 1. Ask the patient if they look after their own medications at home and if they know what they usually take.
   2. Double check the patient’s response with the medicines or medicines list they have brought in with them. The medicines or medicines list may be used as a prompt to assist with patient recollection.
   3. Go through each medicine with the patient and confirm the following aspects of each medicine:
      a. Is this medicine current? Were you still taking it before you were admitted to the hospital?

1. 1. b. How would you usually take the medicine (including dose, frequency, and regularity)?

1. c. Why do you take the medicine and how long have you been taking it for?
2. Check if there are any other medicines that would normally be taken that have not been brought in to the hospital, including ones that have recently been ceased. This is a useful point at which to run through a checklist such as that found on the MMP.
3. Ask if the patient has any allergies or has had any adverse effects from medicines in the past.
4. Document BPMH and reconcile against currently charted medicines.

A BPMH can be documented on the medication chart in the section titled ‘Medicines taken prior to presentation to hospital’. Documentation can also be entered into the patient’s medical record, or on an MMP.

If a discrepancy is identified between the BPMH and medicines on the medication chart, a medical officer or pharmacist should be informed.

When using a patient’s own medicines to assist with compiling a BPMH, it is important to consider that patients may take their medicines differently to the instructions printed on the label. A prescription for 30 tablets with five repeats is likely to last a patient six months. If the dosage changes during that time, the information on the label may not be current. For this reason, it is important to involve the patient in the BPMH process.

Training tools exist to help with the BPMH process. An online module is available from the National Prescribing Service titled ‘Get it Right! Taking a Best Possible Medication History’. This module may be useful if you are unsure, or would like to improve your confidence in taking a BPMH.