Canadians who do not take their medications as prescribed cost the health care system an additional $4 billion. Failure to properly administer medicine accounts for 5% of Canadian hospital admissions, and 5% of physician visits. For employers, the problem results in increased benefit costs, lost productivity, temporary disability and increased absenteeism.

These findings come from "Take Your Pills," a recent paper published by Sun Life Financial that looks at the costs of medication non-adherence and considers some of the reasons why Canadians do not take their medications as they should.

Sun Life notes that many studies have found that people with mental illness are especially at risk, as they may deny or be unaware of their illnesses, they may suffer from drug-related side effects, or they may have a poor relationship with their mental health provider. For example, Sun Life points to one study conducted by Dr. Matthew S. Keene and published in Medscape Psychiatry in 2005 found that 62% of people with depression will relapse, and that one of the greatest predictors of relapse when treatment is pharmacological is non-compliance with medications.

There are other reasons patients may not take their medications, such as complicated packaging (e.g., elderly or arthritic people having difficulty with childproof caps), or because they either have no symptoms or symptom-free periods.

As part of its paper, Sun Life has included a number of strategies on how to increase drug adherence as well as a fact sheet with five steps to promote the importance of taking medication as prescribed.