pill appearance and medication adherence

sometimes it is nice to have a study reaffirming one of the (many) obstacles to delivering high-quality medical care, minimizing medication errors. The annals of internal medicine just had a study confirming the high rate of errors associated with prescribing generic drugs with ever-changing colors, sizes, shapes... (see medication errors with generics ann intern med 2014 in dropbox, or doi:10.7326/M13-2381).  the issue here, which i see almost on a daily basis, is that the patient goes to the pharmacy, gets a refill on a medication, sees it looks totally different from their prior pill, stops taking it because of fear that the new pill was given in error, then comes to me (and i often have to take the time from a busy primary care session to call the pharmacy to make sure it in fact was not an error). obviously, this takes a lot of time, creates angst in the patient, and poses a risk of adverse events by patients not taking their needed medication. and some meds may be really dangerous to stop (eg paroxetine, clonidine).

in this study, they looked at medication nonpersistence (ie not continuing to take meds) in patients with cardiovascular disease post-MI from a health insurance database, specifically looking at 3 classes of meds: b-blockers, ACE-I/ARBs,  and statins. compared case patients (those who discontinued meds) vs controls. they specifically assessed changes in pill color and shape in the year post-MI, noting when there were 2 refills preceding the nonpersistence to see if there were a change in the pill appearance. study sponsored by agency for healthcare research and quality (AHRQ) and the harvard program in therapeutic science. results:

    --29% of 11,513 patients (n=3286) had change in pill appearance, with statins (usually the most important of the meds) having the most changes and b-blockers the least.

    --4574 episodes of nonpersistence (!!!, esp for those within 1 year of MI) were compared to 19881 control episodes

    --AND: the odds of nonpersistence was 34% higher after change in pill color (OR 1.34 [1.12-1.59]) and 66% higher with change in pill shape (OR 1.66 [1.43-1.94]). this was no different if analyzed for 7 days or 60 days of medication nonpersistence.

clearly, it is important and necessary to use generic meds. the quality of these drugs are monitored and show equivalent clinical results when tested. but there is no regulation about the appearance of the pill (though that should be a pretty easy fix). one perspective on this study is that other studies of medication non-adherence have found significantly lower 1-year adherence rates overall in patients on primary prevention (eg statin), with increased adherence in secondary prevention (eg, with documented or high-risk coronary artery disease), and highest in those with an actual event (eg post-MI). so these rather dramatic results from the above study might be even more dramatic in those on meds for asymptomatic conditions (eg hypertension). again, this study speaks to the importance of a coherent medical system, which includes coordinated care in the different venues (outpatient, ER, inpatient...) as well as outside the traditionally-defined areas (including through team structures, which include pharmacy, etc). i would also add, per prior blogs, we should include social factors associated with illness (housing, employment, income inequality, social services...) as part of the mix. this approach/coordination, to variable degrees, is evident throughout the industrialized world (except the US).