Feasibility of laboratory monitoring in community pharmacy by point of care testing of creatinine and potassium in ambulatory elderly at risk for impaired renal function

The prevalence of impaired renal function is high in the Netherlands: 4-5%.
Important risk factors for impaired renal function are age, diabetes, and
cardiovascular diseases. In patients with impaired renal function it is
sometimes necessary to adjust the therapy to prevent medication errors. Without
adjustment, the drug can accumulate in patients at risk and adverse drug
reactions will become manifest. In a study done by Van Dijk et al. dose
adjustments did not take place in 40% of the patients with impaired renal
function at disposal. In the HARM-study 5.6% of the acute hospital admissions
were related to medication and half of the admissions were potentially
preventable. Impaired renal function was one of the potential risk factors for
medication-related hospital admissions. In addition, these preventable hospital
admissions harm individual patients and give high costs, which are an
unnecessary burden for community. According to the Dutch medical guidelines for
diabetes, and cardiovascular diseases, at least once a year renal function has
to be monitored, and if necessary also potassium. It is unknown how often
general practitioners monitor renal function or potassium in these patients and
how often therapy adjustments were performed in the Netherlands. The pharmacist
has a legal treatment responsibility for the patient and therefore information
about laboratory monitoring is essential to assess this responsibility.

Feasibility of laboratory monitoring in community pharmacies by Point-Of-Care
testing creatinine and potassium in ambulatory elderly at risk for impaired
renal function.

Feasibility study:
The pharmacist selects the population at risk for impaired renal function in
the pharmacy computer system for each GP based on the criteria for inclusion.
The GP identify subjects without an actual renal function. An informed consent
letter is send to subjects with unknown renal function to achieve a population
with consent. Eligible subjects with consent are flagged in the computer system
for identification when visiting the pharmacy. If 25-50% of the MDRDs is
unknown, we expect 1-2 patients per week for POC-testing for each GP. Including
subjects for POC-testing is stopped after reaching the desired number of
subjects (4-8 weeks). When one of the subjects visits the pharmacy in the study
period, the subject is asked to participate for POC-testing of creatinine and
potassium in the pharmacy.
For each pharmacy a pharmacist and technician will be trained by the UMC
Utrecht. The trained pharmacist or technician analyses creatinine and potassium
in a blood sample from a finger puncture with the Abbott I-stat 1 in a separate
consulting room. MDRD is calculated with the equation provided by National
Kidney Foundation
(http://www.kidney.org/professionals/kdoqi/gfr_calculator.cfm) If the MDRD is
below the critical value for a drug according the Dutch clinical guideline for
impaired renal function of the KNMP, the pharmacist assesses alerts associated
with impaired renal function for relevant drugs and will give a therapy advice.
All data are registered in the medical record and on the research document. The
pharmacist proposes therapy adjustments directly to GP and communicates these
with the subject. If direct communication with the GP is not possible, the
subject is send home and phoned by either the pharmacist or the GP as soon as
possible.
One week after intervention subjects will be send a questionnaire. After the
study is stopped, a questionnaire will be send to the pharmacy and GPs.

Subjects visiting the pharmacy will be asked to participate for POC-testing
creatinine and potassium by use of a finger prick. POC-testing is only done
when the MDRD is not known at the GP*s.
Based on the MDRD the pharmacist will give a therapy advice: dose adjustment,
frequency adjustment, stopping the drug or changing the drug. In concordance
with the patient and the GP, the pharmacist will effectuate the advice.

One finger prick per patient, if the MDRD is near a critical value (+/- 10%),
the POC-test will be repeated after 7 days. After the intervention the patients
will receive a questionnaire that will take 10 minutes to fill in. Further
constraint and risk for the patient will be minimal and justifies this study in
patients of which the MDRD should be known. Without knowing the MDRD the
pharmacist can not assess alerts for drugs related to impaired renal function
and show his professional responsibility. Taking a blood sample with the finger
prick method is part of routine in medical practice and can not be considered
as an additional risk.