NURS 8730 Week 4 Operational Definition Example

Counting a Sitting-Up Day the Same Way Twice: An Operational Definition for the Mobilization Measure and Five Borderline Records Worked Through

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College of Nursing, Walden University

NURS 8730: Doctoral Seminar III

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Month Day, Year

Counting a Sitting-Up Day the Same Way Twice: An Operational Definition for the Mobilization Measure and Five Borderline Records Worked Through

Why a Definition Needs Edge Cases

A measure that two careful people count differently is two measures. The project's main measure, how often ventilated patients in the unit reach a seated position at the bedside, sounded clear when it was written as an aim. When two reviewers applied it independently to twenty records from the baseline period, they disagreed on five. This document fixes the numerator, denominator and interval in a few lines and then spends most of its length on those five records, because the definition is only as good as its handling of the cases that do not fit neatly. Improvement measurement guidance stresses that operational definitions must be precise enough that different people collecting data at different times get the same result (Provost & Murray, 2011).

The Definition

Unit. A qualifying ventilator day: a calendar day, midnight to midnight, on which an adult in the ICU received invasive mechanical ventilation at any time and had been ventilated continuously for at least 24 hours at 0000 that day.

Exclusions. Days on which, at 0700, the patient had comfort-care orders, an open abdomen, an unstable spinal injury or an active physician order for bed rest.

Numerator. Qualifying days whose recorded peak mobility level was 3 or above. Level 3 is sitting over the edge of the bed with the patient actively holding the position, with or without assistance (Hodgson et al., 2014).

Denominator. All qualifying days, including days on which the safety screen was failed and days with no scale level recorded.

Interval. Calendar week during the baseline and first eight weeks; calendar month afterward.

Source. The flowsheet field for the daily highest mobility level, entered by the bedside nurse at 1800 and editable until 2359.

Five Borderline Records

Record 1: Extubated at 1100, sat up at 1500. The patient was ventilated from 0000 to 1100, then sat at the edge of the bed after extubation. Reviewer A counted the day as a success; reviewer B did not, reasoning that the patient was no longer ventilated when mobilized. Ruling: the day qualifies, because the patient was ventilated during it, and it counts in the numerator, because the measure records the highest level reached that day. This will slightly favor days of extubation. The alternative, counting only activity while ventilated, would require time-stamped entries the flowsheet does not support. The ruling is recorded so the effect can be estimated: days of extubation will be flagged in the data.

Record 2: Passive transfer to a cardiac chair by lift. The patient was moved by ceiling lift to a chair and sat there for two hours, but did not hold the position actively. Reviewer A recorded level 3 or higher because the patient was out of bed; reviewer B recorded level 2. Ruling: level 2. The scale distinguishes passive transfer to a chair, which is a lower level, from active sitting over the edge of the bed. Being out of bed is not the same as being active.

Record 3: Sat at the edge of the bed for one minute, then became hypotensive. The session was stopped under the stopping rules. Ruling: level 3 for the day, because the patient reached and actively held the position; the stopping event is counted separately in the balancing measure. The measure records what was reached, not whether the session went well.

Record 4: Ventilated for 22 hours at midnight. The patient was intubated at 0200 the previous day, so at 0000 had been ventilated for 22 hours. Reviewer A counted the day; reviewer B did not. Ruling: not a qualifying day, because the 24-hour threshold is measured at 0000. The threshold exists so that patients in the first hours after intubation, who are rarely candidates for mobilization, do not dilute the measure. Checking it at a fixed time removes the need to judge.

Record 5: No level recorded, but a physical therapy note describes sitting at the edge of the bed. The nurse left the flowsheet field blank; the therapist's note describes active sitting for five minutes. Ruling: the definition puts such a day among the qualifying days but not among the successes. The source is the flowsheet field, and filling gaps from other notes would reintroduce the free-text reading the prospective measure was designed to avoid. The missing entry will be reported to the nurse the next morning, and the rate of blank fields will be tracked as a data-quality measure.

Checking the Definition

After the rulings were written into the definition, the two reviewers applied it independently to a fresh set of twenty baseline records. They agreed on nineteen. The disagreement was a record in which the nurse had written "dangled" in a free-text note, which the definition now treats as active sitting only if the note says the patient held the position. Agreement on nineteen of twenty is adequate for a unit-level measure, and the check will be repeated on ten records a month during the project, with any new disagreement resolved in writing and added to the definition.

A definition written this way is longer than the one-line version in the aim. That is the point. Run charts can only show real change if every point on them was counted the same way (Perla et al., 2011), and the cases that break a short definition are exactly the ones that appear on busy days.

The rulings also have consequences for the measure's trend that should be known in advance. Rulings 1 and 3 tend to raise the count slightly, because they credit days of extubation and days on which a session stopped early. Rulings 2 and 5 tend to lower it, because they exclude passive transfers and unrecorded activity. Because all four rulings apply equally in the baseline and project periods, they should not create a false shift on the run chart. But they mean the absolute level of the measure is a product of definitional choices, and the final report will say so when it compares the unit's figures with any published rate.

References

Hodgson, C., Needham, D., Haines, K., Bailey, M., Ward, A., Harrold, M., Young, P., Zanni, J., Buhr, H., Higgins, A., Presneill, J., & Berney, S. (2014). Feasibility and inter-rater reliability of the ICU Mobility Scale. Heart & Lung, 43(1), 19-24. https://doi.org/10.1016/j.hrtlng.2013.11.003

Perla, R. J., Provost, L. P., & Murray, S. K. (2011). The run chart: A simple analytical tool for learning from variation in healthcare processes. BMJ Quality & Safety, 20(1), 46-51. https://doi.org/10.1136/bmjqs.2009.037895

Provost, L. P., & Murray, S. K. (2011). The health care data guide: Learning from data for improvement. Jossey-Bass.