Rising trends on folic acid test requests in a middle-income large academic hospital: A low-value care target for improvement

Abstract

Objectives: To evaluate the trends in serum folate test ordering and their abnormal results.

Methods: The authors retrieved data from an anonymized laboratory database from a single, large, academic hospital from Brazil. The authors retrieved serum folate test results, the number of repetitions and other laboratory measurements obtained in the same time window, ordering setting and clinic. The authors then evaluated the trends in test ordering, and prevalence of low (< 3 ng/dL) results, and assessed targets for improvement in test ordering.

Results: From January 1st, 2018, to December 31st, 2022, 181,379 folate tests were ordered from 82,052 patients, with 0.7 % of low results, rising from 33,988 in 2018 to 44,187 in 2022. The outpatient setting was the most frequent (89.5 %). The clinics that most frequently ordered folate tests were Gastroenterology (33 %) and Nephrology (9.8 %). Most patients had more than one test ordered (74.8 %). The 135,787 re-tests were performed in 36,300 patients. Many exams were repeated within three (22,570) or six months (46,881). Only 24,243 repetitions were made more than a year after the prior exam.

Conclusions: Folate test ordering is an increasing trend in this large academic hospital, suggestive of non-clinical guided test ordering and low-value testing.

Keywords: Clinical pathology; Low-value care; Quality; Rational use; Serum folate.

Fig. 1

Temporal trend of the number of folate exams/month. The blue line depicts the number of folate exams per month, while the red line describes the linear trend. The darker dashed gray lines depict the 1st wave of the pandemic.

Fig. 2

Bar graph of the most common ordering clinics of folate exams and their proportion of exams with low results.

Fig. 3

Temporal trend of the number of folate exams/month stratified by ordering clinic.

Fig. 4

Violin plot for serum folate test results. The dashed line depicts the reference value for low values of folate (≤2.99 ng/mL).

Fig. 5

Histogram of the timing of serum folate exams repetitions. The dashed line depicts 90 days from a first test to a repeated test.

Fig. 6

Order setting of exams with repetitions and without repetitions. ICU, Intensive Care Unit; ED, Emergency Department; inpatient refers to patients admitted to hospital, but not on ED or ICUs.