Crowdsourced Asparagus Urinary Odor Population Kinetics

Abstract

The consumption of asparagus is associated with the production of malodorous urine with considerable interindividual variability (IIV). To characterize the urinary odor kinetics after consumption of asparagus spears, we conducted a study with consenting attendees from two American Society for Clinical Pharmacology and Therapeutics (ASCPT) meetings. Subjects were randomized to eat a specific number of asparagus spears, and then asked to report their urinary odor perception. Eighty‐seven subjects were included in the final analysis. A mixed effect proportional odds model was developed that adequately characterized the dose‐response relationship. We estimated the half‐life of the asparagus effect on malodorous urine to be 4.7 hours (relative standard error (RSE) = 13.2%), and identified a dose‐response slope term with good precision (24.3%). Age was found as the predictor of IIV in slope estimates. This study design and tools can be used as a demonstration “crowdsourcing” project for studying population kinetics in organizational and educational settings.

What Can Be Learned From Crowdsourced Population Asparagus Urinary Odor Kinetics?

“…As a starting point for data analysis, the previously developed ASCPT model was used . This model aimed to characterize the relationship between the number of asparagus spears consumed and the observed odor scores over time.…”

“…The odor score (pharmacodynamics) was then modeled as a multinomial logistic regression with A ( t ) as a dependent variable. Since A ( t ) was not observed, the model can be described as a kinetic‐pharmacodynamic model …”

“…We were inspired by the recent success of the crowdsourcing asparagus study conducted during the American Society for Clinical Pharmacology and Therapeutics (ASCPT) Annual Meeting and identified this study as an important tool (model) and opportunity to address both the educational and fun aspects of learning. The published crowdsourcing study also provided an opportunity to reemphasize the “Learn and Confirm” paradigm, which influenced our operational and scientific objectives.…”

“…The published crowdsourcing study also provided an opportunity to reemphasize the “Learn and Confirm” paradigm, which influenced our operational and scientific objectives. Consequently, the lessons learned from the previous study were used to alter selected design and operational aspects of our study. There was a need to redesign the data collection process by developing a web‐based application for topics related to the overall management of the study, from randomization to data recording and real‐time data exploration.…”

“…To execute the current study within the timeframe of the meeting (and a data collection period of 72 hours postingestion of asparagus), we decided to use the protocol from the original study at the ASCPT meeting but with some minor adaptations. The greatest operational difference from the ASCPT study was the development of the electronic case report form (eCRF) and the study management system that was implemented as an R‐Shiny app, which was installed on an Amazon cloud web server and made available to the study participants on smart phones and computers via the internet.…”