Table 1.
Distribution by discrepancy class and examples of conflicting information
| Discrepancy Class | Examples | Occurrence | |||
| Sig fragment | Free-text instructions | N | % of examined | % with discrepancies | |
| Complex regimen | TID | TID ×1 week and then as needed | 137 | 4.70 | 29.15 |
| Q6–8H | 1 po tid×7d, then 1 po bid×7d, then q6–8 h PRN pain; take with food | ||||
| QHS | Start with 40 mg a day for a week, if no muscle pain increase to 80 mg | ||||
| QD | Take 2 tablets in AM and 1 tablet in PM | ||||
| QD | 80 mg po qod alternating with 40 mg | ||||
| QD | Take 1 tab qd, except on monday and friday. Take 120 mg on monday and friday | ||||
| QD | 1 qd except sunday | ||||
| Dosage range expanded inappropriately | 5MG take 1 tab Q4H PRN pain | Take 1–2 tablets every 4 h as needed for pain | 76 | 2.61 | 16.17 |
| Coumadin 5MG take 1 tab QPM | 1–3 tabs…adjusted as necessary for PT levels | ||||
| Frequency mismatch | Q8H | May take 1–2 q 4 h PRN pain | 66 | 2.26 | 14.04 |
| TID | Take 30cc every 6 h as needed for pain | ||||
| ×1 | 1 daily | ||||
| PRN mismatch | 10MG take 1 QHS | As needed for sleep short term only | 58 | 1.99 | 12.34 |
| 1 Application QD | Apply as often as needed for itching | ||||
| 5MG take 1 tab QHS | Take one tablet by mouth every night at bedtime as needed for sleep | ||||
| Dose mismatch | 50MG take 1 tab QD | Take 1 1/2 tablets daily | 58 | 1.99 | 12.34 |
| 500MG take 1 tab as directed | Take 2 g (4 tablets) 1 h prior to your dental procedure | ||||
| 30 units QHS | Inject 25 units every night at bedtime | ||||
| Imprecise conversion of daytime and around-the-clock frequencies | TID | Take one tablet every 8 h as needed. Do not exceed 4 tablets in a day | 22 | 0.75 | 4.68 |
| Q8H | Take 3× per day with meals | ||||
| QID | Take every 6 h (with food) for 4 days. After that may take only as needed | ||||
| Frequency range extended inappropriately | 2 Puffs Q4H | 2 Puffs every 1–4 h as needed | 19 | 0.65 | 4.04 |
| 1 Application BID | Apply to affected area of legs qd–bid | ||||
| QD | May use up to 5 times a day, PRN to affected area | ||||
| Route mismatch | OD | For left eye/use as directed | 17 | 0.58 | 3.62 |
| JTUBE | Take PO not Jtube | ||||
| PO | 2 Drops in the ear four times a day for earwax | ||||
| PO | Apply to scalp lesions for 15 min QD | ||||
| Dosage form mismatch | Lotion | Pt needs liquid version, NOT lotion | 10 | 0.34 | 2.13 |
| Tablet | Swallow capsule whole | ||||
| Tablet | 20 cc bid for 10 days | ||||
| Duration mismatch | 10 days | One tab po bid×7 days | 4 | 0.14 | 0.85 |
| 5 days | Apply to affected eye/s three times a day for 5–7 days | ||||
| Quantity mismatch | Dispense 250 MG | Dispense 10 pills | 2 | 0.07 | 0.43 |
| Drug name mismatch | Procardia | Procardia XL | 1 | 0.03 | 0.21 |
Percentages represent a fraction of total prescriptions examined (n=2914) and a fraction of prescriptions with discrepancies (n=470).