The Impact of a Standardized Pre-visit Laboratory Testing Panel in the Internal Medicine Outpatient Clinic: a Controlled “On-Off” Trial

Background: In several settings, a shorter time to diagnosis has been shown to lead to improved clinical outcomes. The implementation of a rapid laboratory testing allows for a pre-visit testing in the outpatient clinic, meaning that test results are available during the first outpatient visit. Objective: To determine whether the pre-visit laboratory testing leads to a shorter time to diagnosis in the general internal medicine outpatient clinic. Design: An “on-off” trial, allocating subjects to one of two treatment arms in consecutive alternating blocks. Participants: All new referrals to the internal medicine outpatient clinic of a university hospital were included, excluding second opinions. A total of 595 patients were eligible; one person declined to participate, leaving data from 594 patients for analysis. Intervention: In the intervention group, patients had a standardized pre-visit laboratory testing before the first visit. Main Measures: The primary outcome was the time to diagnosis. Secondary outcomes were the correctness of the preliminary diagnosis on the first day, health care utilization, and patient and physician satisfaction. Key Results: There was no difference in time to diagnosis between the two groups (median 35 days vs 35 days; hazard ratio 1.03 [0.87–1.22]; p =.71). The pre-visit testing group had higher proportions of both correct preliminary diagnoses on day 1 (24% vs 14%; p =.003) and diagnostic workups being completed on day 1 (10% vs 3%; p <.001). The intervention group had more laboratory tests done (50.0 [interquartile range (IQR) 39.0–69.0] vs 43.0 [IQR 31.0–68.5]; p <.001). Otherwise, there were no differences between the groups. Conclusions: Pre-visit testing did not lead to a shorter overall time to diagnosis. However, a greater proportion of patients had a correct diagnosis on the first day. Further studies should focus on customizing pre-visit laboratory panels, to improve their efficacy. Trial Registration: NL500

Compliance with platelet count monitoring recommendations and management of possible heparin-induced thrombocytopenia in hospitalized patients receiving low-molecular-weight heparin

BACKGROUND: Summaries of product characteristics (SPCs) and clinical guideline recommendations are available for monitoring the platelet count for heparin-induced thrombocytopenia (HIT) in patients receiving low-molecular-weight heparin (LMWH). Testing for the presence of heparin-platelet factor 4 antibodies (HPF4-Ab) and starting alternative anticoagulation is recommended when HIT is suspected. OBJECTIVE: To investigate the frequency of compliance with recommendations for platelet count monitoring and management of possible HIT in hospitalized patients receiving prophylaxis and treatment dosing of LMWH for at least 5 consecutive days. METHODS: A retrospective cohort study within the Utrecht Patient Oriented Database (UPOD) was conducted. For all inpatients, all episodes of exposure to dalteparin or nadroparin for at least 5 consecutive days in 2004-2005 were selected. In 4 different nonexclusive groups of patients (all pts. receiving dalteparin, all pts. receiving nadroparin, surgical pts. with a prophylactic dose of either dalteparin or nadroparin, and pts. exposed to unfractionated heparin [UFH] within 100 days before receiving either dalteparin or nadroparin), compliance with recommendations for platelet count monitoring from SPCs and a clinical guideline was studied. The frequency of compliance with these recommendations was determined. In addition, it was determined whether patient and treatment characteristics were associated with regular platelet count monitoring. Finally, the frequency of testing for HPF4-Ab and the initiation of danaparoid treatment in patients with a drop of at least 50% in platelet count were investigated. RESULTS: A total of 6804 patients, with 7770 episodes of LMWH treatment, were included in the analysis. The frequency of compliance with platelet count monitoring recommendations was 26.3% for all patients receiving dalteparin, 35.6% for all patients receiving nadroparin, 23.0% for surgical patients receiving prophylactic dosing of either dalteparin or nadroparin, and 41.5% for patients exposed to UFH within 100 days before the start of either dalteparin or nadroparin treatment. Regular platelet count monitoring was strongly positively associated with medical patients (relative risk [RR] 2.33), surgical patients (RR 2.03), critically ill patients (RR 2.80), and those with recent exposure to UFH (RR 2.19). The frequency of testing for HPF4-Ab was 5.4% and the initiation of alternative anticoagulation with danaparoid in patients with a 50% drop in platelet count was 0%. CONCLUSIONS: The results suggest that compliance with recommendations for platelet count monitoring and management of possible HIT is low at our institution. Policies and tools to improve compliance with recommended laboratory monitoring should be developed to secure the safe use of LMWH and other medications

The role of antibody indexes in clinical virology

Background: Serological techniques are an essential part of the diagnostic tools used in clinical virology. Among these techniques, antibody indexes are not novel