Chickenpox Case Estimation in Acyclovir Pharmacy Survey and Early Bioterrorism Detection

Prescription surveillance for early detection system of emerging and reemerging infectious disease outbreaks

Based on prescriptions filled at external pharmacies, prescription surveillance (PS) in Japan has been reporting the estimated numbers of influenza and varicella patients and people prescribed certain drugs since 2009. Every morning, this system estimates the numbers of patients from the numbers of prescriptions filled nationwide for neuraminidase inhibitors, anti-herpes virus drugs, antibiotic drugs, antipyretic analgesics, and multi-ingredient cold medications. Moreover, it can detect "unexplained" infectious diseases that are not explained as infectious diseases monitored by other surveillance systems. Such "unexplained" infectious diseases might be emerging and re-emerging infectious diseases including bioterrorism attacks, which are reportedly difficult to diagnose, at least in early outbreak stages. To ascertain the system's potential benefits, this study examined schemes to detect "unexplained" infectious diseases using PS information. The numbers of patients prescribed the respective drugs are first regressed on the known infectious diseases, time trends, and dummies for day-of-the-week, holidays, and days following a holiday. Known infectious diseases are defined as covered by the National Official Sentinel Surveillance for Infectious Diseases under the Infection Control Law. After the numbers of patients from PS are compared with the predicted numbers of patients, their probabilities of occurrence are calculated. We examined the system's prospective operation from January 2017 through July 2018. The criterion we used to define aberrations varied, from 0.01 to 10^-7. For criteria of 0.01 and 10^-7 we found 254 and 15 aberrations, respectively. We confirmed its feasibility and effectiveness.

Evaluation of the global action plan on antimicrobial resistance in Japan during its first eighteen months

Antimicrobial resistance (AMR) has garnered the most attention among public health concerns worldwide. Japan formulated a national action plan for AMR in April 2016. The plan seeks to reduce the amount of antimicrobials used in 2020 to two-thirds of the use recorded in 2013. Prescription surveillance (PS) is being used to monitor trends in the amount of antimicrobials used. PS estimates the number of patients prescribed an antimicrobial each day. The number of patients who were prescribed an antimicrobial under the action plan was analyzed by including dummy variables with other control variables. Data from April 1, 2011 to 30 September 30, 2017 were analyzed. When the number of patients with an infectious disease (1 of 13 specified diseases) served as a dummy variable, estimates indicated that the coefficient of that dummy variable was not significant. If the number of patients with an infectious disease (1 of 13 specified diseases) was excluded as an explanatory variable, then the estimated coefficient was significant. The global action plan in Japan might not reduce the amount of antimicrobials used. The current results indicated that the number of patients who were prescribed an antimicrobial did not decrease significantly after initiation of the action plan. This finding does not exclude the possibility that the average amount of antimicrobials used per patient has decreased.

Proposition of real-time precise prediction model of infectious disease patients from Prescription Surveillance using the National Database of Electronic Medical Claims

The incidence of common pediatric infectious diseases has been monitored officially at sentinel medical institutions in Japan. However, the numbers of affected patients are not provided. Prescription Surveillance (PS), which infers the number of patients with influenza, varicella, and gastrointestinal infections from data related to prescriptions at external pharmacies, provides estimates to the public the following morning. This study assessed the prediction ability of the incidence of common pediatric infectious diseases from PS information using the National Database of Electronic Medical Claims (NDBEMC): the number of patients prescribed neuraminidase inhibitors, anti-herpes virus drugs, antibiotic drugs, antipyretic analgesics, and multi-ingredient cold medications. The diseases include RS virus infection, pharyngoconjunctival fever, hand, foot and mouth disease, erythema infectiosum, exanthem subitum, pertussis, herpangina, influenza, varicella, and gastrointestinal infection. For comparison, we used the estimated number of patients who were prescribed neuraminidase inhibitor in PS, which had been confirmed already for precision, and provided estimates to the general public via the internet. The discrepancy rates of all considered diseases between the reported number in NDBEMC and the predicted numbers of patients from PS were less than the value in NI counts and the coefficients of determination in the estimation were from .8109 to .9825. These predictions were sufficiently precise to provide to the general public.