NU673 Unit 10 PHQ-9 Measurement-Based Care Case Example

The Number Set the Next Step: A Measurement-Based Care Case Following Six PHQ-9 Scores Over Sixteen Weeks in a 36-Year-Old Commercial Electrician

[Student Name]

Purdue University Global

NU673: PMHNP Diagnosis and Management Across the Lifespan I

Unit 10 Measurement-Based Care Case

[Instructor Name]

[Date]

The patient is composite; scores, doses and dates are bracketed.

The Patient and the Rules

Mr. [K.] is a [36]-year-old commercial electrician who presented with [three] months of feeling down, no pleasure in his softball league, poor sleep, low energy, poor concentration on job sites and feelings of worthlessness after a divorce. He had one previous episode at [25] that resolved without treatment. He denied suicidal intent; his answer to the ninth PHQ-9 item was [1], "several days," and a safety assessment found no plan or intent. He drank [two] beers most evenings and agreed to reduce this.

The PHQ-9 is a nine-item self-report measure of depressive symptoms with severity bands from minimal to severe, validated in primary care (Kroenke et al., 2001). In a later study of its use for monitoring treatment, the minimal clinically important difference for an individual was estimated at [5] points (Löwe et al., 2004).

Rules agreed with him at intake, before any treatment:

1. The PHQ-9 is completed at every visit before he sees me.

2. A fall of less than [20] percent after [four] weeks on a dose leads to a dose increase if tolerated.

3. Response means a fall of at least [50] percent; remission means a score below [5].

4. Item 9 above [0] at any visit leads to a safety review that day.

These rules follow the principle of measurement-based care, in which treatment decisions are driven by repeated standardized measurement against predefined thresholds. In a randomized trial in outpatients with moderate to severe depression, measurement-based care produced higher rates of response and remission and shorter times to both than standard care, with more treatment adjustments and higher doses (Guo et al., 2015).

Visit 1: Intake, Week 0

Measured: PHQ-9 [21], severe. Item 9 [1]; safety plan written. Read: severe major depressive episode, recurrent. Decided: sertraline [50] mg daily; weekly supportive sessions with a plan for behavioral activation; reduce alcohol to weekends. Next measure: week [4].

Visit 2: Week 4

Measured: PHQ-9 [18]. Item 9 [0]. Read: a fall of [3] points, [14] percent, below the [20] percent threshold and below the [5]-point change that would indicate a meaningful individual improvement. Decided: increase sertraline to [100] mg; mild nausea had resolved by week two. Next measure: week [8].

Visit 3: Week 8

Measured: PHQ-9 [14]. Read: a fall of [7] points from intake, [33] percent. Meaningful change, but short of response. On [100] mg for four weeks, the fall from [18] to [14] was [22] percent, just above the threshold for keeping the dose. Decided: he preferred to try a higher dose rather than wait; the rules allowed either. Sertraline increased to [150] mg. Behavioral activation added: two softball practices a week. Next measure: week [12].

Visit 4: Week 12

Measured: PHQ-9 [9]. Read: a fall of [12] points from intake, [57] percent. Response achieved. Mild range. Decided: continue the current dose; continue behavioral activation; review sleep. Next measure: week [14].

Visit 5: Week 14

Measured: PHQ-9 [6]. Read: continued improvement; not yet remission. Decided: no change. He had returned to his league and slept better. Next measure: week [16].

Visit 6: Week 16

Measured: PHQ-9 [4]. Read: remission, a score below [5]. Remission was reached because each dose was judged against a number at a fixed time, not left to run because the patient seemed a little better. Decided: keep sertraline at [150] mg for a maintenance period agreed with him, at least half a year beyond remission and longer given this is his second episode; monthly PHQ-9 for three months, then every [three] months. Next measure: week [20].

How the Scores Were Shared With Him

At every visit the score was shown to him on a simple graph, with the thresholds for response and remission drawn in. This had three effects. It made the decisions transparent: when the dose went up at week four, he could see why, even though he felt a little better. It gave him a way to notice his own progress when his mood was still low, since the line was moving before he felt it. And it made the conversation about the next step a shared one; at week eight, he chose the higher dose himself after looking at the graph. He said at week sixteen that seeing the numbers fall had helped him "trust the medicine" when he had been skeptical at the start.

Item-Level Changes

The total score does not show which symptoms improved. At intake his highest items were sleep, energy and loss of interest, each scored [3]. By week twelve, sleep and energy had fallen to [1], but loss of interest was still [2], which is why behavioral activation was emphasized at that visit. By week sixteen all items were [1] or [0]. Item 9 was [0] from week four onward, and the safety plan was reviewed and kept in place until week twelve. Looking at items as well as totals allowed the plan to target the symptom that was lagging rather than simply waiting for the total to fall.

What Measurement Changed

Without measurement, the visit at week four would probably have ended with "give it more time," since he said he felt "a bit better." The score showed that the change was small. At week eight, his own sense was that he was "much better," but the score placed him short of response, and the dose was increased. Each adjustment came weeks earlier than it might have otherwise.

What Would Have Happened Under the Rules if He Had Not Improved

The rules were designed to act in both directions. Had his score stayed above [15] at week eight despite the dose increase, the next step would have been a switch to a different antidepressant or the addition of structured psychotherapy, chosen with him. Had item 9 risen at any visit, the safety review that day would have taken priority over any dose decision. Writing these branches down at intake meant that neither of us had to invent a response under pressure at a difficult visit.

Limitations

The PHQ-9 relies on self-report, and a patient who wants to please the clinician may underreport. His alcohol use, which fell over the period, may have contributed to improvement. And a single case cannot show that measurement-based care caused his recovery; the trial evidence shows that it helps on average.

References

Guo, T., Xiang, Y.-T., Xiao, L., Hu, C.-Q., Chiu, H. F. K., Ungvari, G. S., Correll, C. U., Lai, K. Y. C., Feng, L., Geng, Y., Feng, Y., & Wang, G. (2015). Measurement-based care versus standard care for major depression: A randomized controlled trial with blind raters. American Journal of Psychiatry, 172(10), 1004-1013. https://doi.org/10.1176/appi.ajp.2015.14050652

Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606-613. https://doi.org/10.1046/j.1525-1497.2001.016009606.x

Löwe, B., Unützer, J., Callahan, C. M., Perkins, A. J., & Kroenke, K. (2004). Monitoring depression treatment outcomes with the Patient Health Questionnaire-9. Medical Care, 42(12), 1194-1201. https://doi.org/10.1097/00005650-200412000-00006