Impact of an Interprofessional Collaborative Quality Improvement Initiative to Decrease Inappropriate Thyroid Function Testing

Abstract

Background: Published data show that thyroid function laboratory tests are often ordered inappropriately in the acute care setting, which leads to unnecessary costs and inappropriate therapy decisions. Pilot data at our institution indicated that approximately two-thirds of the thyroid-stimulating hormone (TSH) laboratories were unnecessary, correlating to a potential cost avoidance of more than $20,000 annually. The purpose of this study was to improve the appropriateness of thyroid function test ordering with a multipronged initiative. Methodology: This controlled, single-center, before and after study included inpatients or emergency department (ED) patients at Wake Forest Baptist Medical Center who were at least 18 years of age and had a TSH level ordered during the study period. Patients with a history of thyroid cancer were excluded. The initiative included an electronic ordering intervention, direct education of providers (medical residents, attendings, and clinical pharmacists), and distribution of pocket information cards with appropriate ordering criteria. The primary outcome was the number and percentage of inappropriate TSH tests ordered before and after implementing the 3 interventions. Secondary outcomes included cost savings, inappropriate changes in thyroid therapy based on improperly ordered tests, and the number of free T4 lab tests ordered on patients with a TSH within the therapeutic range. Results: All 3 interventions were implemented, except for education of ED residents and faculty, who chose to forgo the direct education component. Inappropriate ordering of TSH levels decreased from 63 to 50 (13% reduction, P = .062) after implementation. Inappropriate TSH ordering decreased across all services, except in the ED. Inappropriate Free T4 orders decreased from 191 to 133 (30% reduction, P = .01). There were no therapy changes based on inappropriate TSH orders. Extrapolated annual cost savings were approximately $6,000. Conclusion: This multipronged interprofessional collaborative quality improvement initiative was associated with a nonstatistically significant reduction in inappropriate TSH orders, statistically significant reduction in inappropriate free T4 orders, and cost savings. There was a reduction in inappropriate ordering across all services except the ED, which may have been due the ED not participating in the direct education component of the initiative.

Introduction

Laboratory testing is a fundamental aspect of a health care system which, when inappropriate, contributes to the high cost of care and use of resources. ¹ Overutilization of lab testing is prevalent in hospital practice, including academic medical centers.^2,3 Reasons for inappropriate ordering that are especially applicable to teaching hospitals include a lack of certainty and experience among prescribers, desire for more information in anticipation of questioning from upper-level residents and attending physicians, and lack of awareness of the cost of tests. This overutilization can lead to unnecessary costs, unwarranted consults, and inappropriate therapy decisions.^1,2 Interventions focused on inappropriate testing aim to reduce cost and improve the quality of patient care. ⁴

A systematic review evaluating the effectiveness of interventions to reduce inappropriate ordering of thyroid function tests (TFTs) was published in 2016. ⁵ The studies in this review used a variety of interventions with education, protocols, and feedback being the most common. Of the 27 studies included, 14 were conducted in a hospital setting. Only 3 studies reported evaluation of computer-based test ordering, 2 of which were published over 2 decades ago (1988 and 1994). The more recent study was limited because the only intervention implemented was displaying the cost of the test being ordered. In addition, over the years, studies have seen the number of TFT orders increase substantially and vary widely across different institutions and services. In 2013, it was reported that the annual rate for thyroid-stimulating hormone (TSH) test orders ranged from 6 to 356 per 1,000 patients. ⁶ The landscape regarding laboratory test ordering has changed dramatically over the years, warranting additional studies that include interventions targeting electronic ordering. To address this concern at our institution, members of the Pharmacy Department and Endocrine Section designed and implemented a multifaceted intervention to improve the ordering of TFTs and conducted this study to evaluate its effectiveness.

Methods

Study Design and Patient Population

This retrospective, single-center, preintervention and postintervention study was performed at Wake Forest Baptist Medical Center (WFBMC), an 885-bed academic medical center with over 40,000 admissions and 100,000 emergency department (ED) visits annually. This study was reviewed and approved by the Institutional Review Board at Wake Forest University (IRB00054289), and informed consent was not required.

Eligible patients were 18 years of age or older, were admitted to the hospital or seen in the ED of WFBMC, and had a TSH ordered during the study periods, which were January to March of 2018 (preintervention) and 2019 (postintervention). Patients were excluded if they had a history of thyroid cancer. One full week (designated the “study week”) in each of these months was selected for further analysis of TSH orders. Corresponding months of each year were selected in order to capture residents and other learners during the same stage of their training. One week per month was selected with the intention of assessing the intervention on many different medical teams. Resident rotations are typically 4 weeks in length, so evaluating 3 consecutive weeks would limit the assessment to only 1 team per service.

To evaluate the impact on TSH ordering, patients with a TSH test result during the study weeks were identified by running a query of our electronic medical record (EMR) database. Charts were then reviewed in random order until 33 patients per study week were identified for inclusion, totaling 99 patients per group. Patients were included only once per study period. To evaluate the impact on the ordering of free T4 levels, a second query was run to identify inappropriately ordered free T4 levels (defined as a free T4 ordered on a patient who had an existing TSH in the reference range) during the full 3-month study period in each group. Due to a relatively low number of baseline T3 orders, the impact of the intervention on the ordering of free T3 tests was not assessed.

Interventions

The study team hypothesized that educating residents, faculty, and advanced practice providers would influence behavior and decrease inappropriate ordering of TFTs. Criteria for the appropriate ordering of TSH, free T4, and free T3 were developed by endocrinology faculty based on available guidelines and evidence. Clinical scenarios in which it was deemed appropriate to order a TSH level in an acutely ill patient (in the hospital or ED) were: an unexplained heart rate of <60 bpm or >100 bpm, unexplained hypothermia or hyperthermia, unexplained tachyarrhythmia or heart block, or seizure, coma, or delirium without a clear etiology. These criteria were incorporated into all educational interventions and used to assess outcomes. The initiative had 3 discrete interventions: direct education with content delivered in a large group setting, pocket card distribution, and an order screen alert in the EMR (Appendix A). An endocrinology fellow and a pharmacist provided face-to-face presentations to internal medicine interns and residents who rotate through various services such as general medicine, cardiology, oncology, neurology, psychiatry, and critical care units. Education was also provided to selected hospitalists, general medicine attendings, and clinical pharmacists. At the completion of the face-to-face presentations, pocket cards were distributed to all in attendance. These pocket cards detailed the clinical scenarios in which it would be appropriate to order a TSH, free T4, and free T3 in the inpatient and ED settings.

The EMR order screen alert appeared when providers placed an order for a TSH, free T4, or free T3 laboratory test (unique alert for each individual test; Appendix A Figure 1, Figure 2, and Figure 3 respectively). The alert encouraged the clinician to stop and assess whether it was appropriate to order the specific TFT for this particular patient. The alert detailed the criteria for the appropriate ordering of the respective TFT. The TSH alert also noted,

Non-Thyroidal Illness Syndrome (euthyroid sick syndrome) is common in hospitalized patients due to numerous factors that affect thyroid test results in acutely ill euthyroid patients. To avoid clinically uninterpretable results, assess TSH only when clinical suspicion of thyroid dysfunction is high and there are objective signs of thyroid dysfunction.

Initial chart review was performed by the first listed author and all questionable scenarios were subsequently reviewed by endocrinology physicians.

Objectives

The primary outcome was to measure the impact of the initiative on the number and percentage of inappropriate TSH levels ordered. Secondary outcomes included cost savings associated with the initiative, reduction in inappropriate free T4 orders, and therapy decisions associated with inappropriate TSH orders.

Statistical Analysis

Assuming a difference in inappropriate TSH ordering of 15%, statistical power of 80%, and a 2-sided alpha of .05, a minimum of 95 patients in each group were required to show statistical significance. Nominal data were compared using a chi-square test.

Results

The study team provided face-to-face educational sessions during November of 2018. All services participated in direct education and received the pocket cards, except the ED who declined the education. The order screen intervention went live in the EMR in January of 2019 throughout the institution, so the ED was exposed to this intervention.

Of 1,825 TSH levels ordered January through March of 2018, 450 were ordered during the prespecified study weeks and 99 charts were randomly selected for study inclusion. Of 1,679 TSH ordered January through March of 2019, 442 were ordered during the prespecified study weeks and 99 randomly selected for study inclusion. This represents an 8% reduction in the total number of TSH orders after initiative implementation. The proportion of tests ordered by the ED increased dramatically, while the proportion of tests ordered by all other services decreased or stayed relatively constant (Table 1).

Table 1.

Number of TSH Orders Per Service.

Service	Preintervention (n = 99)	Postintervention (n = 99)
ED	31	55
Cardiology	19	8
Hospitalist	16	10
Neurology	14	6
General medicine	11	8
Psychiatry	4	5
Other a	4	7

Note. TSH = thyroid-stimulating hormone; ED = emergency department.

^aNeurosciences intensive care unit, medical intensive care unit, nephrology.

Inappropriately ordered TSH levels decreased from 63 to 50 (13% difference, P = .062) after implementing the initiative (Figure 1). The number and percentage of inappropriate TSH laboratory orders decreased across all services, except the ED and the “other” category of services (Figures 2 and 3).

Figure 1.

Number of inappropriate TSH tests.

Note. TSH = thyroid-stimulating hormone.

Figure 2.

Number of inappropriate TSH by service.

Note. TSH = thyroid-stimulating hormone; ED = emergency department.

Figure 3.

Percentage of inappropriate TSH by service.

Note. TSH = thyroid-stimulating hormone; ED = emergency department.

The secondary outcome of inappropriate free T4 levels ordered decreased from 191 to 133 (30% reduction, P = .01). There were no therapy changes based on inappropriate TSH tests. Extrapolated annual cost savings were approximately $5,000 for TSH and $800 for free T4, totaling an estimated cost savings of $5,800.

Since the ED chose to forgo the direct educational components of the initiative, the study team decided to conduct a non-a priori subgroup analysis of non-ED services. This subgroup analysis showed that 47 of 68 TSH orders (69%) in the preintervention group and 19 of 44 TSH orders (43%) in the postintervention group were ordered inappropriately (30% relative reduction; p < .01).

Discussion

Cost containment is an important concern for hospitals and health systems. Unnecessary laboratory orders increase health care costs. Diagnostic stewardship is a practical method of cost containment. Realizing this, the study team chose to evaluate the practical implementation of a multipronged quality improvement initiative to improve the TFT ordering behaviors of clinicians regarding various thyroid monitoring tests.

Direct education of residents, attending physicians, and pharmacists, plus display of appropriateness criteria on the ordering screens for TFTs were associated with an overall decrease in TSH orders, as well as a decrease in inappropriate ordering of TSH and free T4 levels. This resulted in cost savings equivalent to approximately $6,000 per year. If the rate of inappropriate TSH orders was reduced to 0%, it would correlate to an annual cost savings of approximately $20,000.

This study has certain limitations. Appropriateness of TSH orders was determined through chart review and therefore was dependent on accurate and complete documentation in the EMR. The sample size was based on an estimated reduction in inappropriate TSH tests of at least 15%; this hindered our ability to show a statistically significant difference in our primary outcome. Unfortunately, we were unable to implement all interventions in all services, since the ED declined to participate in our direct education presentations. However, when the ED data were removed from the analysis, there was a statistically significant reduction in inappropriate TSH orders of 30%, P < .01. The fact that the initiative was effective in all services except where it was not fully implemented may actually support its benefit. Furthermore, this study targeted clinicians at a single center, which potentially makes the findings not generalizable to other sites. However, since the interventions used education and a modification of electronic ordering screens, it would be feasible to implement this initiative at most institutions. Finally, the study team was unable to quantify the extent to which each individual intervention affected the outcomes. However, the results indicate that educational presentations had a substantial impact, given the difference in outcomes between the services that received education versus those that declined.

Conclusion

This multipronged quality improvement initiative was associated with a nonstatistically significant reduction in inappropriate TSH ordering, a statistically significant reduction in free T4 orders, and a definite cost savings. A reduction in inappropriate ordering occurred across all services except the ED, which may have been due to the inability to provide education to the ED physicians. This study shows the benefit of pharmacists working with physicians to improve diagnostic stewardship of laboratory tests used to diagnosis disease and monitor drug therapy.

Appendix A

Figure 1.

Electronic Medical Record Ordering Screen Alert for TSH.

Figure 2.

Electronic Medical Record Ordering Screen Alert for Free T4.

Figure 3.

Electronic Medical Record Ordering Screen Alert for Free T3.