An algorithm to simulate missing data for mixed meal tolerance test response curves.

BACKGROUND: Response curves formed by analyte concentrations measured at sampled time points after consuming a mixed meal are increasingly being used to characterize responses to differing diets. Unfortunately, owing to a variety of reasons, analyte concentrations for some of the time points may be missing. OBJECTIVES: This study aimed to develop an algorithm to estimate the missing values at sampled time points in the analyte response curve to a mixed meal tolerance test (MMTT). METHODS: We developed an algorithm to simulate the missing postprandial concentration values for an MMTT. The algorithm was developed to handle any number of missing values for 2 or less consecutive missing values. The algorithm was tested on MMTT response curve data for glucose and triglyceride measurements in data from 3 different studies with 2119 postprandial MMTT response curves. The algorithm was validated by removing concentration values that were not missing and replacing them with the algorithm simulated values. The AUC error between the actual curve and simulated curves were also calculated. A web-based application was developed to automatically simulate missing values for an uploaded MMTT data set. RESULTS: The algorithm was programmed in Python and the resulting web-based application and a video tutorial were provided. The validation indicated good agreement between actual and simulated values with error increasing for less frequently sampled time points. The study with the mean minimum error of glucose concentrations was 6.2 ± 2.1 mg/dL and study with the mean maximum error of glucose concentrations was 11.3 ± 4.7 mg/dL. Triglycerides had 16.1 ± 6.2 mg/dL mean error. The AUC error was small ranging between 0.01% and 0.28%. CONCLUSIONS: The presented algorithm reconstructs postprandial response curves with estimations of values that are missing.

A Survey Among Cadets at the United States Military Academy on Knowledge and Wearing of Permethrin-Treated Uniforms and the Risk of Tick-Borne Diseases.

INTRODUCTION: The Army uses permethrin-treated uniforms as the primary method to protect soldiers from tick-borne diseases. Permethrin binds strongly to fabric and provides long-term protection against many blood-feeding arthropods. However, protection decreases if the uniforms are not washed and cared for according to label instructions. This study was conducted among cadets at the United States Military Academy (USMA) at West Point, NY, to determine what the cadets know about permethrin and how they care for and wear their uniforms. West Point is in an area with high rates of tick-borne disease transmission. A survey was developed to determine what cadets know about the threat of tick-borne diseases and if they wear and maintain their uniforms in a manner that effectively maintains permethrin levels. MATERIALS AND METHODS: A 16-question survey was developed and submitted to the local review board for approval. The study was classified as human subjects research according to 32CFR219 and met the requirements for exempt status under 32CFR219.104(d)(2)(i). After receiving approval, a hard copy survey was distributed among cadets with efforts to sample at least 50 members from each cadet class. RESULTS: A total of 319 cadets provided responses to the survey questions, representing more than 7% of the cadet population at the USMA. The results showed most cadets knew their uniforms were treated with permethrin, but less than half knew there are specific instructions attached to their uniforms describing how the uniforms should be laundered. From the cadets who knew there were instructions, most admittedly did not follow the instructions. Sixteen percent of cadets said they had dry-cleaned their uniforms. This is a process known to remove most of the permethrin. The majority of cadets viewed the risk of tick-borne disease at West Point to be moderate or lower. CONCLUSIONS: This study provides a basic understanding of the wear patterns of permethrin-treated uniforms among cadets at the USMA. It is also one of the few studies to measure knowledge and uniform-wearing behavior among service members since the Army switched to factory-treated uniforms in 2013. The results indicate that compliance with uniform laundry and care instructions is low. This information is useful to develop training plans and educate cadets how they can wear and take care of their permethrin-treated uniforms to better protect themselves from tick-borne diseases.