Barriers to Ordering
Twelve ED patients with possible pulmonary embolism. For each, decide the next step. The ordering environment around each case (how long the scanner queue is, and what the order screen makes you do) is set at random. At the end you'll see whether those barriers changed what you ordered, and whether they changed it in the right patients.
Before you start
Treat each case as your patient on a normal shift. Read it, say how likely you are to order a CT pulmonary angiogram, then choose the next step. If the order screen gets in your way, do what you'd really do: push through, or cancel and pick something else.
About 10 minutes. There's no feedback until the end, so earlier cases don't shape later ones.
Group codes use lowercase letters, digits and dashes, up to 32 characters.
How the experiment works
This is a factorial vignette experiment. The clinical facts in each case are fixed, so the right answer is known: four cases need no CT, four need one after a positive D-dimer, and four need one outright. Four barriers are switched on or off independently for each case, balanced so that within each risk group, each barrier is on for exactly two of the four cases.
| Barrier | What happens | Kind |
|---|---|---|
| Wells hard stop | CT order won't release until you score Wells; it then says whether the CT fits the pathway. | Targeted friction |
| Justification | A required indication and a free-text reason of at least 25 characters. | Blunt friction |
| Radiology approval | Page the radiologist, wait for the callback, answer their question. | Blunt friction |
| Long CT queue | The scanner status says ~4 hours instead of ~30 minutes. | Context |
The callback wait is shortened to 12 seconds. The 4-hour queue can't be simulated, only shown.
Sources
- Wells PS, Anderson DR, Rodger M, et al. Derivation of a simple clinical model to categorize patients' probability of pulmonary embolism. Thromb Haemost 2000;83:416–20.
- Kline JA, Mitchell AM, Kabrhel C, Richman PB, Courtney DM. Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism. J Thromb Haemost 2004;2:1247–55.
- Righini M, Van Es J, Den Exter PL, et al. Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism: the ADJUST-PE study. JAMA 2014;311:1117–24.
- Raja AS, Ip IK, Prevedello LM, et al. Effect of computerized clinical decision support on the use and yield of CT pulmonary angiography in the emergency department. Radiology 2012;262:468–74.
- Atzmüller C, Steiner PM. Experimental vignette studies in survey research. Methodology 2010;6:128–38.
Cases are fictional teaching vignettes, not clinical guidance.