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Poor Adherence to Opioid Pain Management Regimens

Patient non-adherence to commonly used prescription protocols is a growing concern.
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How well do patients understand common prescription instructions? Does twice a day mean the same thing to all patients? What about three times a day—does that mean breakfast, lunch, and dinner? Not surprisingly, a large proportion of patients do not comprehend common prescription instructions, leading to possible over- or underuse of medication.

This concern led the authors to evaluate comprehension of commonly used prescription terms. The following article reviews their results and recommendations.

Reason for Concern

Most clinicians are aware of the increasing rates of opioid prescribing over the past decade.1 Although opioids have long been used as pain management tools, this increase in prescription rates has been accompanied by concerns regarding potential adverse reactions, iatrogenic illnesses, substance abuse, and even death.2,3

More recently, some researchers have also pointed to the flip side of increased opioid prescribing—underuse of these medications. One study found that approximately 50% of patients do not take their medications as prescribed.4 Underuse, for whatever reason, can undermine the effectiveness of treatment, inflate health care costs, and result in aberrant medication behaviors such as hoarding, supplementing prescribed pain medications with other drugs that are perceived to be less risky, and poor adherence to medical treatment in general. Indeed, a team of investigators recently found that some perceived medication failures maybe a function of poor adherence rather than the value of the medication per se.5

Rates of Non-Adherence

In general, a review of the current medical literature on adherence found that published estimates of non-adherence to medications ranged from 15% to 93%. When pain management was examined specifically, the investigators found non-adherence rates ranging from 9.2% to 77.8% among cancer patients.6

Studies examining patient self-reported adherence reveal similar trends. Broekmans et al examined self-report adherence in a sample of 281 patients at a pain treatment center.7 They found a total non-adherence rate of 48%, with 14% reporting overuse, 34% reporting underuse, and 2% reporting both overuse and underuse. In a study of attitudes toward pain medications, Rosser et al found 47.6% reported underuse, 52% reported that they often skipped doses, and 23.5% to 30.4% described overuse.8

Although there clearly is a great deal of concern about overuse both in the health care arena and the public, the literature strongly suggests that underuse is much more common.

Factors Contributing To Non-Adherence


Several studies have pointed to elevated risk of overuse of opioid medications among patients with a history of substance abuse in general.9 A relationship between overuse of opioid medications and smoking cigarettes, for example, has been noted.8 Other factors noted to play a role in overuse of opioid medications include severe somatization,10 psychiatric comorbidities (substance use disorder), younger age,11 and alcohol-related arrests.12


Lewis et al identified 10 explanations patients endorsed for underusing medications13:

  • Desire to minimize medication intake in general
  • Concerns about adverse side effects and addiction
  • Desire to make the medication regimen more “acceptable”
  • Cost of medications
  • Using medications symptomatically
  • Using medications strategically (such as skipping doses in anticipation of driving)
  • Substituting or supplementing medications (using over-the-counter medications, etc.)
  • Problems with doctor-patient communication
  • Perceived medication ineffect-iveness
  • Pressure from family and friends

Complexity of Treatment

Some research suggests that the complexity of treatment is negatively correlated with treatment adherence. A review of literature on the relationship between dose regimen and medication compliance using electronic monitoring devices suggests that simpler regimens requiring fewer doses are associated with greater compliance rates.5

Type of Dosing Schedule.

One variable that appears to be associated with opioid adherence is the type of dosing schedule. Research in this area has tended to focus on time-scheduled dosing compared with pain contingent dosing. A study of cancer patients prescribed opioid analgesic medications found that those placed on time-scheduled dosing adhered 84.5% to 90.8% of the time, while those prescribed medications PRN (as needed), only adhered to medication guidelines 22.2% to 26.7% of the time.6 Time-scheduled dosing also played a role in better adherence among pediatric patients. In a study of children receiving short-term opioid treatment following tonsillectomy, investigators found that children placed on time-scheduled dosing were more adherent and achieved significantly greater pain attenuation than those receiving PRN dosing.14

Patient Comprehension of Common Prescription Instructions

Clearly, several complex factors affect treatment adherence. One obvious and commonly discussed factor is the extent to which patients comprehend the instructions provided. Although recent studies suggest that patients report feeling poorly educated and cite problems communicating with physicians, little research has examined patient comprehension of common prescription instructions. The authors conducted a study examining the extent to which patients in an outpatient pain management clinic comprehend commonly used prescription instructions.

A random sample of 300 patients with established treatment at an outpatient pain management clinic were administered a researcher-derived questionnaire during a routine follow-up visit. Participation in the study was voluntary and anonymous. A simple questionnaire developed by the researchers consisted of 6 questions designed to assess patient comprehension of some commonly used prescription instructions (Table 1). The questionnaire could easily be divided into 3 types of instructions:

  • Number of doses per day (eg, twice daily).
  • Time-scheduled dosing (eg, every 8 hours).
  • Latin abbreviation medical terms describing number of doses per day (eg, tid).

The setting of the data collection included 2 prescribing pain doctors and 3 prescribing nurse practitioners. Since the questionnaires were administered randomly and anonymously, it was not possible to examine differences in patient responses as a function of characteristics of individual prescribers.

Simple descriptive statistics were deemed sufficient to examine the extent to which participants responded accurately to each item. Inter-item comparisons were conducted using a chi square (χ2). Further, ANOVA was used to analyze the effect of complexity of treatment across item types.

Last updated on: April 14, 2015
First published on: December 1, 2013