Warning labels on outpatient prescription vials not so great after all

Everyone has seen them, I know you have. Those little colored labels that the pharmacy slaps on your bottle when you get a prescription: “May cause drowsiness”, “Avoid excess sun”, “Do not take aspirin products without doctor approval” and so on. There are a ton of them. I remember seeing them lined up in front of me when I was working retail. Sometimes it became a game to see how many you could fit on the bottle without covering up valuable information for the patient. I’ve also been in pharmacies where the warning labels were simply printed alongside the medication label.

Well, it appears that this tradition may not be the best way to warn patients about potential issues with their medication. I mean, who really reads those things anyway?

A small study recently published in the journal PLoS ONE took a look at these warning labels and determined that people really don’t pay attention. Not surprising.

Some “researchers” tracked the eye movement of 32 participants – 15 in their 20s and 17 aged 50 or older – as they looked at 5 prescription vials. Then they asked the participants to pick the warning labels out of a lineup of 10 labels of different color combinations, of which 5 were the same as the ones on the bottle the viewed.

Turns out that older people were less likely than younger people to remember the warning labels they examined. “More specifically, the probability of noticing a PWL was lower for the older (Estimated LSM ± SEM 54.0%±17.6%) relative to the younger population (91.8%±6.1%; P = 0.0396); yet, no evidence for age differences were apparent on the probability of noticing the white prescription label (100.0%±8.6E−7% for the older population and 100.0%±3.3E−7 for the younger population).” In other words they had no problem with the actual prescription label, just the warning labels.

The study concluded that it had more to do with attention span than memory. “This serial process suggests that the older participants may have done worse in the recognition task, not because of problems with memory, but simply because they were less likely to attend to the PWLs [Prescription Warning Label] during the initial viewing.”

Most interesting though might be the fact that color may have little to do with remembering the warning. “Across a variety of colors, we found that PWL  color did little to increase the probability of it being noticed (P>0.70), or recognition of, the PWL.” This is definitely contrary to what I thought about color and recognition.

So what’s the recommendation? “All participants viewed the white pharmacy label, indicating that people’s expectation was that goal relevant information would be presented at that location. This interpretation suggests that the placement of the PWLs as a separate label that is spatially distinct from the white pharmacy label may actually hinder the label’s ability to garner attention.” Yep, dump the PWLs and put the information on the actual label. Interesting concept.

I wouldn’t put too much stock in the study as it was really quite small, but it’s worth talking about and spending some time looking at our labeling practices. With that said, one thing to remember is that the best way to warn patients about potential harm from their prescriptions is to talk to them. Yeah, actually spend a little face time with the patient discussing their medications. Go figure.


Sundar RP, Becker MW, Bello NM, Bix L (2012) Quantifying Age-Related Differences in Information Processing Behaviors When Viewing Prescription Drug Labels. PLoS ONE 7(6): e38819. doi:10.1371/journal.pone.0038819

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