The Tricky Nature of Medication Compliance
Review by Osterberg L, Blaschke T. Adherence to Medication. N Engl J Med. 2005;353:487-497.
Adherence to (or compliance with) a medication regimen is generally defined as the extent to which patients take medications as prescribed by their healthcare providers. Adherence rates are typically higher among patients with acute conditions, as compared with those with chronic conditions; persistence among patients with chronic conditions is disappointingly low, dropping most drastically after the first six months of therapy. Of all medication-related hospital admissions in the United States, 33% to 69% are because of poor medication adherence, with a resultant cost of approximately $100 billion a year.
Electronic medication-monitoring devices have provided very detailed information about the patterns of medication-taking behavior. Studies using these monitors have shown six general patterns of taking medication among patients treated for chronic illnesses who continue to take their medications. Approximately one-sixth come close to perfect adherence to a regimen; one-sixth take nearly all doses, but with some timing irregularity; one-sixth miss an occasional single day’s dose and have some timing inconsistency; one-sixth take drug holidays three to four times a year, with occasional omissions of doses; one-sixth have a drug holiday monthly or more often, with frequent omissions of doses; and one-sixth take few or no doses while giving the impression of good adherence.
Poor adherence to medication regimens is common, contributing to substantial worsening of disease, death, and increased healthcare costs. Practitioners should always look for poor adherence and can enhance adherence by emphasizing the value of a patient’s regimen, making the regimen simple, and customizing the regimen to the patient’s lifestyle. Asking patients nonjudgmentally about medication-taking behavior is a practical strategy for identifying poor adherence. A collaborative approach to care augments adherence. Patients who have difficulty maintaining adequate adherence need more intensive strategies than do patients who have less difficulty with adherence, a more forgiving medication regimen, or both. Innovative methods of managing chronic diseases have had some success in improving adherence when a regimen has been difficult to follow.
The New Clostridium Difficile—What Does It Mean?
McDonald LC, Killgore GE, Thompson A, et al. An epidemic, toxic gene-variant of Clostridium difficile. N Eng J Med. 2005;353;2433-2441.
Clostridium difficile is the only anaerobe that causes nosocomial infections. It colonizes the colon in 3% of the healthy population and about 20% to 40% of hospitalized patients.
This study was done in response to reports of increasing rate and severity of this infection. This study looked at healthcare facilities in Pennsylvania, Maine, Georgia, Oregon, Illinois, and New Jersey and did indeed find a new strain of Clostridium difficile isolate which showed 100% resistance to gatifloxacin and moxifloxacin, compared with no resistance in the historic strain.
Resistance to clindamycin was similar in both the groups, which was measured at 79%. This particular strain secretes 16 to 23 times more toxins A and B in vitro than other strains. And in this study the new strain accounted for 51% of the infections compared with 17% in the historic control isolates. Fluoroquinolones were implicated alone or in combination with other antibiotics in 52% of the cases. Those infected with the new strain were more likely to have higher rates of toxic megacolon, need for colectomy, leukemoid reaction, shock, and death. Like any disease, the interaction between host and pathogen is key to severity, thereby making patients who are chronically ill and elderly more susceptible.