Tuesday, April 24, 2007

Follow-up, and continuity of care important in ensuring medication adherence

Follow-up, and continuity of care important in ensuring medication adherence

Patients who stop taking statins are more likely to re-start if they have good follow-up and they see the same doctor who originally prescribed for them, according to a study published today. The authors note that adherence to prescribed statins is relatively poor, with many patients stopping them within a year of initiation. They therefore attempted to determine some of the factors that result in patients re-starting treatment using a case-crossover study design.

Data on new users of a statin were obtained from healthcare databases in British Columbia, Canada, Medication dispensing for these individuals was then followed to determine those who became non-adherent, defined as 90 days from finishing one supply to having a new one dispensed. These individuals were then followed to determine what factors prompted re-starting statin use.

Between January 1997 and June 2004, a total of 253,951 patients were started on a statin. After exclusions (mainly those started on cerivastatin), there were 239,911 studied. Of these, over half had (129,167, 53.8%) had a period of non-adherence that lasted for at least 90 days. About half of these (48%) restarted within a year of stopping, and 60% within two years. The factor most strongly associated with re-starting was, perhaps not surprisingly, incident MI - the odds ratio for re-starting after MI was 12.2 (95% CI, 8.9-16.9) - although the number of actual events was small. Numerically, the most frequent factor was visiting any doctor (OR, 2.9; 95% CI, 2.8-3.0), and visiting the doctor who started the statin was the second-strongest factor (OR 6.1; 95% CI, 5.9-6.3). Having a cholesterol test and hospital admission for any other cardiovascular condition were also factors.

The authors conclude that patients frequently interrupt statin use, with long periods of non-adherence. The most important factor in re-starting use is visiting the doctor who originally started the therapy, especially when the visit is combined with a cholesterol test. The message therefore, is that regular follow-up and continuity of care are major factors likely to improve long-term adherence to statins.

Arch Intern Med 2007; 167: 847-52 (link to abstract)

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