For the patient, knowledge of therapeutic
coverage heightens the understanding of the impact
of a particular level of compliance. For the doctor
and the pharmacist, instruction of the patient is
facilitated and the possibility is provided to praise
patients with good compliance and to increase
motivation in patients with poor compliance.
Calculation of the shortest and longest intervals
between two doses, the percentage of days with
correct number of doses taken and the distribution
of intervals between doses complete the compli-
ance report.
27.9 How is compliance
classified: typical patternFull Compliance
The patient executes the prescribed dosing regimen
to a high degree of punctuality. The limits of devia-
tion from strict punctuality vary from one pharma-
ceutical product to another depending on the
forgiveness of each (Urquhart, 1998). Thus, there
are no fixed percentages of prescribed doses taken
that can realistically provide a blanket definition of
‘full’ vis ‘partial’ compliance. Moreover, as dis-
cussed above, some pharmaceutical products enter
the market with the prescribed drug-dosing regi-
men calling for considerably more drug to taken
than is necessary. With such products, patients may
omit half or more of prescribed doses and still end
up with a good outcome of treatment. Of course,
from a strictly behavioral point of view, patients
can stray quite far from the prescribed dosing regi-
men, but the over-riding consideration is whether
the pharmaceutical in question provides enough
forgiveness to allow the patients to have good
clinical outcomes, despite the omission or delay
of many doses.
Partial compliance
The best definition of ‘partial compliance’ is
a dosing history that provides a level of drug
exposure that is sufficient only to elicit a partial
therapeutic response. With exceptionally unforgiv-
ing drugs, a patient can take 100% of prescribed
doses, but nevertheless have an inadequate
therapeutic response simply because of erratic tim-
ing of doses taken. It is a product-specific matter,
dependent on the forgiveness of the product in
question. Note that we use the term ‘product’
instead of ‘drug’, because the formulation of
some drugs can make a big difference in forgive-
ness, based on the use of controlled-release
formulations.Noncompliance
It is useful to recognize a level of drug exposure
that could properly be called ‘de minimis’, that is,
too little to matter. Again this is a product-specific
matter. In the absence of reliable data on forgive-
ness, one might reasonably assume that an intake
that, over time, averaged less than 50% of what was
prescribed could be called ‘noncompliance’.
Obviously, one level of noncompliance that is
quite clear is zero intake.Overcompliance
This term is used when there is evidence that the
patient has taken more than the prescribed amount
of medication. The outcomes of overcompliance
are product specific, but can be expected to include
increased numbers and severity of adverse effects,
with or without increased levels of therapeutic
action.Bottom line
From the perspective of treatment outcomes,
questions of how much compliance is enough,
not enough and too much are product specific.
From the behavioral perspective, one might set
up arbitrary bounds, based simply on how far one
strays from the instructions given. A common
error made by many clinical researchers is to
confuse the two, and mistakenly use the beha-
vioral limits as determinants of treatment out-
comes.362 CH27 PATIENT COMPLIANCE: PHARMIONICS, A NEW DISCIPLINE