Compliance (sometimes called adherence) is the extent to which patients follow treatment instructions. There are four types of noncompliance leading to medication errors.
1. The patient fails to obtain the medication. Some studies sug-gest that one third of patients never have their prescriptions filled. Some patients leave the hospital without obtaining their discharge medications, whereas others leave the hospital without having their prehospitalization medications resumed. Some patients cannot afford the medications prescribed.
2.The patient fails to take the medication as prescribed. Examples include wrong dosage, wrong frequency of administration, improper timing or sequencing of administration, wrong route or technique of administration, or taking medication for the wrong purpose. This usually results from inadequate communication between the patient and the prescriber and the pharmacist.
3. The patient prematurely discontinues the medication. This can occur, for instance, if the patient incorrectly assumes that the medication is no longer needed because the bottle is empty or symptomatic improvement has occurred.
4. The patient (or another person) takes medication inappropri-ately. For example, the patient may share a medication with others for any of several reasons.
Several factors encourage noncompliance. Some diseases cause no symptoms (eg, hypertension); patients with these diseases therefore have no symptoms to remind them to take their medica-tions. Patients with painful conditions such as arthritis may con-tinually change medications in the hope of finding a better one.Characteristics of the therapy itself can limit the degree of compliance; patients taking a drug once a day are much more likely to be compliant than those taking a drug four times a day. Various patient factors also play a role in compliance. Patients living alone are much less likely to be compliant than married patients of the same age. Packaging may also be a deterrent to compliance—elderly arthritic patients often have difficulty opening their medication containers. Lack of transportation as well as various social or personal beliefs about medications are like-wise barriers to compliance.
Strategies for improving compliance include enhanced com-munication between the patient and health care team members; assessment of personal, social, and economic conditions (often reflected in the patient’s lifestyle); development of a routine for taking medications (eg, at mealtimes if the patient has regular meals); provision of systems to assist taking medications (ie, containers that separate drug doses by day of the week, or medica-tion alarm clocks that remind patients to take their medications); and mailing of refill reminders by the pharmacist to patients tak-ing drugs chronically. The patient who is likely to discontinue a medication because of a perceived drug-related problem should receive instruction about how to monitor and understand the effects of the medication. Compliance can often be improved by enlisting the patient’s active participation in the treatment.