RETRACTED ARTICLE: Seasonal and Secular Periodicities Identified in the Dynamics of US FDA Medical Devices (1976–2020): Portends Intrinsic Industrial Transformation and Independence of Certain Crises

Background: The US Food and Drug Administration (FDA) regulates medical devices (MD), which are predicated on a concoction of economic and policy forces (e.g., supply/demand, crises, patents). Assuming that the number of FDA MD (Premarketing Notifications (PMN), Approvals (PMAs), and their sum) Applications behaves similarly to those of other econometrics, this work explores the hypothesis of the existence (and, if so, the length scale(s)) of economic cycles (periodicities). Methods: Beyond summary statistics, the monthly (May, 1976 to December, 2020) number of observed FDA MD Applications are investigated via an assortment of time series techniques (including: Discrete Wavelet Transform, Running Moving Average Filter (RMAF), Complete Ensemble Empirical Mode with Adaptive Noise decomposition (CEEMDAN), and Seasonal Trend Loess (STL) decomposition) to exhaustively search and characterize such periodicities. Results: The data were found to be non-normal, non-stationary (fractional order of integration < 1), non-linear, and strongly persistent (Hurst > 0.5). Importantly, periodicities exist and follow seasonal, 1 year short-term, 5-6 year (Juglar), and a single 24-year medium-term (Kuznets) period (when considering the total number of MD Applications). Economic crises (e.g., COVID-19) do not seem to affect the evolution of the periodicities. Conclusions: This work concludes that (1) PMA and PMN data may be viewed as a proxy measure of the MD industry; (2) periodicities exists in the data with time lengths associated with seasonal/1-year, Juglar and Kuznets affects; (4) these metrics do not seem affected by specific crises (such as COVID-19) (similarly with other econometrics used in periodicity assessments); (5) PMNs and PMAs evolve inversely and suggest a structural industrial transformation; (6) Total MDs are predicted to continue their decline into the mid-2020s prior to recovery.
5 figures, 4 tables. Ther Innov Regul Sci (2021)