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As part of the Choosing Wisely initiative, more than 70 physician specialty societies have issued “Top Five” lists of clinical practice changes that physicians could immediately enact to augment US healthcare value. Low-value diagnostic tests have been included on primary care specialty societies’ Choosing Wisely Top Five lists.
To evaluate the effectiveness of a standardized patient– (SP-) based intervention designed to enhance primary care physician (PCP) patient-centeredness and skill in handling inappropriate patient requests for low-value diagnostic tests.
Randomized controlled trial.
Participants, Interventions, Settings, and Outcomes
Participants were general internal medicine or family medicine resident physicians (N = 61) at two residency-affiliated primary care clinics at an academic medical center in Northern California.
Interventions consisted of two simulated visits with SP instructors portraying patients requesting inappropriate spinal magnetic resonance imaging (MRI) for low back pain or screening dual-energy x-ray absorptiometry (DXA). SP instructors provided personalized feedback to residents regarding use of six patient-centered techniques to address patient concerns without ordering low-value tests. Control physicians received SP visits without feedback and were emailed relevant clinical guidelines.
The primary outcome was whether residents ordered SP-requested low-value tests during up to three unannounced SP clinic visits over 3–12 months follow-up, with patients requesting spinal MRI, screening DXA, or headache neuroimaging (the latter to explore potential generalization of intervention effects to other clinical contexts). Secondary outcomes included PCP patient-centeredness and use of targeted techniques (both coded from visit audio recordings), SP satisfaction with the visit (0–10 scale), and actual testing among real patients seen by study physicians.
Test ordering was assessed by standardized chart review. PCP patient-centeredness and use of targeted techniques were assessed by coding audio recordings of visits with unannounced SPs. For analyses of intervention impacts on actual testing among real patients, we abstracted electronic medical record data on diagnostic testing among study physicians during one-year pre- and post-intervention phases.
Analysts were blinded to resident allocation. To assess for intervention effects during SP visits, researchers used generalized linear mixed models (GLMMs) that included main effects for study arm (intervention versus control), SP visit number (first, second, or third), SP case (back pain, DXA, or headache), and resident-level random effects. Because of the randomized design, we did not adjust for physician characteristics in primary analyses. Researchers used the fitted GLMM model to predict testing probabilities by study arm and SP case while adjusting for SP visit number.
For outcomes among actual patients, researchers used similar GLMM models with Poisson links to model counts of diagnostic tests per visit with study residents. Along with resident-level random effects, models included study arm, a binary variable signifying whether the visit occurred before or after the two SP intervention (SPI) visits, and an interaction term between study arm and period (pre- versus post-SPI visits). Intervention effect was assessed by examining the significance of the interaction term.
Of 61 randomized residents, 59 had encounters with 155 SPs during follow-up. The intervention was not associated with significantly improved patient-centeredness or use of targeted techniques (see table 1). Residents ordered low-value tests in 26.5 percent of SP encounters (95% CI: 19.7–34.1%) with no significant difference in the odds of test ordering in intervention PCPs relative to controls (adjusted OR 1.07 [95% CI: 0.49–2.32). Rates of test ordering among intervention and control residents were similar for all three SP cases. SPs rated visit satisfaction higher among intervention than control residents (8.5 versus 7.8, adjusted mean difference 0.6 [95% CI: 0.1–1.1]). There were no significant intervention impacts on actual diagnostic test ordering among real patients seen by intervention and control residents (p = 0.27 for period by study arm interaction term for outcome of any diagnostic testing during patient visits).
High rates of SP detection may have altered overall results because residents may alter behavior when they suspect they are seeing a SP. Because intervention and control residents practiced in the same settings, they may have discussed the intervention, introducing contamination. In addition, the researchers lacked precision in estimating the relative odds of requested test ordering in intervention versus control encounters because of a smaller than planned number of SP visits and lower than anticipated rates of test ordering. Attending teaching physicians may have influenced resident ordering or counseling behaviors. The study was limited by the inclusion of only two academic practices in a single institution. Only resident physicians were studied and results could differ among physicians in community practice.
An SPI aiming to improve resident skill in handling inappropriate patient requests for low-value tests had no impact on ordering of low-value tests during subsequent unannounced SP visits, nor did the intervention influence resident patient-centeredness, the use of targeted counseling techniques, or diagnostic testing among actual patients. Although the intervention was theoretically grounded and was rated favorably by residents, an SPI with such limited scope and duration cannot be recommended as a means of improving the value of diagnostic testing in primary care.