HI501 Unit 4 Decision Support Rule Design Example

Metformin and a Falling eGFR: A Unit 4 Decision Support Rule Design Tested Against Thirty Days of Orders and Cut From 212 Interruptions to 27

[Student Name]

Purdue University Global

HI501: Health Informatics

Unit 4 Decision Support Rule Design

[Instructor Name]

[Date]

Harlow Ridge Health, its orders and its counts are composite; the safety communication and studies cited are real.

Problem

Metformin is the most common first medicine for type 2 diabetes, and it is cleared by the kidneys. Federal labeling, revised in 2016, says it should not be used when the estimated glomerular filtration rate (eGFR) is below 30, should not be started when eGFR is between 30 and 45, and should be paused around iodinated contrast imaging in patients with an eGFR between 30 and 60 (U.S. Food and Drug Administration [FDA], 2016). A systematic review supported that more permissive approach, finding that the risk of lactic acidosis in patients with mild to moderate kidney disease was low (Inzucchi et al., 2014). At Harlow Ridge, inpatient pharmacists catch problem orders by scanning a daily report, which misses orders placed after it runs and patients whose kidney function falls during the stay.

Draft Specification

1. Rule name: Metformin and kidney function.

2. Purpose: prevent metformin use below eGFR 30, avoid new starts between 30 and 45, and pause metformin around contrast imaging between 30 and 60.

3. Triggers: signing a new metformin order, or a new eGFR result posting for a patient with an active metformin order, or a contrast imaging order for a patient with an active metformin order.

4. Data inputs: the most recent eGFR within 90 days, the active medication list, imaging orders and the dialysis flag.

5. Logic: compare the latest eGFR with 30, 45 and 60 according to the trigger.

6. Exclusions: patients flagged as on comfort-focused care; orders already marked for discontinuation.

7. Recipient: the ordering prescriber.

8. Format: interruptive alert at signing or on result posting.

9. Action offered: discontinue metformin in one click.

10. Override reasons: eGFR value believed erroneous; benefit outweighs risk per nephrology; patient on dialysis and order intended to stop; other, with text.

11. Owner: Pharmacy and Therapeutics Committee, reviewed every six months.

Retrospective Run

The draft logic was run against 30 days of composite past orders and results without firing anything. It would have fired 212 times:

1. New metformin order, latest eGFR below 30: 9 firings.

2. Active order, new eGFR result below 30 during the stay: 14 firings.

3. Active order continued, latest eGFR between 30 and 45: 121 firings.

4. New metformin order, latest eGFR between 30 and 45: 18 firings.

5. Contrast imaging ordered, active metformin, eGFR between 30 and 60: 50 firings.

More than half of the draft rule's firings, 121 of 212, would have interrupted prescribers about patients for whom the labeling allows metformin to continue.

Redesign

The first version of any rule tends to fire too often, and the remedy is to match each scenario to the right person, time and format, the core of effective decision support (Bates et al., 2003).

1. Scenario 1, new order with eGFR below 30: interruptive alert to the prescriber at signing, with discontinuation offered in one click. Expected about 9 a month.

2. Scenario 4, new start with eGFR between 30 and 45: interruptive alert at signing, since starting is not recommended in this range. Expected about 18 a month.

3. Scenario 2, eGFR falls below 30 during the stay: no interruption for the prescriber, who may not be in the chart; instead a task goes to the unit pharmacist's queue, who contacts the team. About 14 a month.

4. Scenario 3, continued therapy with eGFR between 30 and 45: no alert at all. The order screen and the medication list display the latest eGFR beside the metformin line, so anyone reviewing the order sees it.

5. Scenario 5, contrast imaging: a pharmacist task tied to the imaging order, prompting a hold order at the time of the study and an eGFR recheck at 48 hours. About 50 a month.

Interruptive firings fall from 212 to about 27 a month. The rest of the work moves to pharmacists, who already perform this check by hand, or becomes passive information on the screen.

Measures After Go-Live

1. Interruptive firings per month, expected about 27.

2. Override rate for each interruptive scenario, with a review if it exceeds 50 percent.

3. Pharmacist task completion within four hours.

4. Patients receiving metformin with a current eGFR below 30, measured from administration records, the outcome the rule exists to reduce.

Why Not a Hard Stop

A hard stop that blocks signing below eGFR 30 was considered and rejected. eGFR values can be wrong or outdated, and a patient whose kidney injury is resolving may be safe to resume metformin within days. A strong interruptive alert with a one-click discontinue action, plus required override reasons, keeps the decision with the prescriber while making the safe choice the easiest one. The override reasons are not a formality: they become the review material for the Pharmacy and Therapeutics Committee every six months, and a cluster of overrides citing an erroneous eGFR, for example, would point to a laboratory or interface problem rather than a prescribing one.

References

Bates, D. W., Kuperman, G. J., Wang, S., Gandhi, T., Kittler, A., Volk, L., Spurr, C., Khorasani, R., Tanasijevic, M., & Middleton, B. (2003). Ten commandments for effective clinical decision support: Making the practice of evidence-based medicine a reality. Journal of the American Medical Informatics Association, 10(6), 523-530. https://doi.org/10.1197/jamia.M1370

Inzucchi, S. E., Lipska, K. J., Mayo, H., Bailey, C. J., & McGuire, D. K. (2014). Metformin in patients with type 2 diabetes and kidney disease: A systematic review. JAMA, 312(24), 2668-2675. https://doi.org/10.1001/jama.2014.15298

U.S. Food and Drug Administration. (2016). FDA drug safety communication: FDA revises warnings regarding use of the diabetes medicine metformin in certain patients with reduced kidney function.