Expert Recommendations on Frequency of Utilization of Common Laboratory Tests in Medical Inpatients: a Canadian Consensus Study.

BACKGROUND: Repetitive inpatient laboratory testing in the face of clinical stability is a marker of low-value care. However, for commonly encountered clinical scenarios on medical units, there are no guidelines defining appropriate use criteria for laboratory tests. OBJECTIVE: This study seeks to establish consensus-based recommendations for the utilization of common laboratory tests in medical inpatients. DESIGN: This study uses a modified Delphi method. Participants completed two rounds of an online survey to determine appropriate testing frequencies for selected laboratory tests in commonly encountered clinical scenarios. Consensus was defined as agreement by at least 80% of participants. PARTICIPANTS: Participants were 36 experts in internal medicine across Canada defined as internists in independent practice for ≥ 5 years with experience in medical education, quality improvement, or both. Experts represented 8 of the 10 Canadian provinces and 13 of 17 academic institutions. MAIN MEASURES: Laboratory tests and clinical scenarios included were those that were considered common on medical units. The final survey contained a total of 45 clinical scenarios looking at the utilization of six laboratory tests (complete blood count, electrolytes, creatinine, urea, international normalized ratio, and partial thromboplastin time). The possible frequency choices were every 2-4 h, 6-8 h, twice a day, daily, every 2-3 days, weekly, or none unless there was specific diagnostic suspicion. These scenarios were reviewed by two internists with training in quality improvement and survey methods. KEY RESULTS: Of the 45 initial clinical scenarios included, we reached consensus on 17 scenarios. We reached weak consensus on an additional 19 scenarios by combining two adjacent frequency categories. CONCLUSIONS: A Canadian expert panel of internists has provided frequency recommendations on the utilization of six common laboratory tests in medical inpatients. These recommendations need validation in prospective studies to assess whether restrictive versus liberal laboratory test ordering impacts patient outcomes.

Association between Leflunomide and Pulmonary Hypertension.

Rationale: Pulmonary hypertension (PH) has been described in patients treated with leflunomide. Objectives: To assess the association between leflunomide and PH. Methods: We identified incident cases of PH in patients treated with leflunomide from the French PH Registry and through the pharmacoVIGIlAnce in Pulmonary ArTerial Hypertension (VIGIAPATH) program between September 1999 to December 2019. PH etiology, clinical, functional, radiologic, and hemodynamic characteristics were reviewed at baseline and follow-up. A pharmacovigilance disproportionality analysis using the World Health Organization's global database was conducted. We then investigated the effect of leflunomide on human pulmonary endothelial cells. Data are expressed as median (min-max). Results: Twenty-eight patients treated with leflunomide before PH diagnosis was identified. A total of 21 (75%) had another risk factor for PH and 2 had two risk factors. The median time between leflunomide initiation and PH diagnosis was 32 months (1-120). Right heart catheterization confirmed precapillary PH with a cardiac index of 2.37 L⋅min-1 ⋅m-2 (1.19-3.1) and elevated pulmonary vascular resistance at 9.63 Wood Units (3.6-22.1) without nitric oxide reversibility. Five patients (17.9%) had no other risk factor for PH besides exposure to leflunomide. No significant hemodynamic improvement was observed after leflunomide withdrawal. The pharmacovigilance disproportionality analysis using the World Health Organization's database revealed a significant overrepresentation of leflunomide among reported pulmonary arterial hypertension-adverse drug reactions. In vitro studies showed the dose-dependent toxicity of leflunomide on human pulmonary endothelial cells. Conclusions: PH associated with leflunomide is rare and usually associated with other risk factors. The pharmacovigilance analysis suggests an association reinforced by experimental data.