Study Finds Kitchen Spoons Increase Risk of Medication Errors

Research published in the Annals of Internal Medicine warns against the common practice of using household spoons to estimate doses of liquid medicine.

Despite the availability of pharmacy-approved dosing cups, droppers, spoons, and syringes, some patients are still tempted to reach for the nearest kitchen spoon when administering liquid medicine. The FDA discourages the practice, and new research indicates that it may increase the chance of dosing errors by even practiced, confident caregivers.

The study, led by Brian Wansink, author of Mindless Eating: Why We Eat More Than We Think, examined the influence of spoon size on college students’ powers of estimation. A total of 195 subjects were first asked to pour exactly 1 teaspoon (5 mL) of liquid cold medicine into a regular teaspoon, then pour the exact same dose into a second medium-sized spoon, and then a third larger spoon. Researchers followed with a confidence assessment, asking subjects how secure they were in the accuracy and efficacy of the doses they poured.

Athough most reported high levels of confidence, researchers found that dosages varied directly with spoon size. When using the larger spoon, participants overdosed by 11.6%; when using the smaller spoon, they underdosed by 8.4%.

Since most cold medications are taken every 4 to 8 hours for the duration of a patient’s illness, frequent under- or overdosing, even by seemingly insignificant amounts, can have a cumulative impact of reduced efficacy or other consequences. The researchers also identify spoon dosing as a major cause of pediatric poisonings and emphasize the importance of patient education to increase awareness of the problem.

Pharmacists can play a key role in error prevention by ensuring access to accurate measuring devices and by reminding customers to faithfully use them when pouring liquid medicine for themselves or their families.