1to measure initiation and data that do exist, outside of a small number of integrated healthcare systems, are often insufficient to draw any valid conclusions. 5 Initiation is the first component in the taxonomy and the first step to understanding why patients do not take their prescribed medications. Measuring medication initiation provides important baseline rates of primary nonadherence in acute and chronic conditions. Reported rates of noninitiation have been shown to vary between 2.3% and 50% (weighed average [SD], 5.1% [1.3%]) across studies. 6 This large disparity in rates may reflect the multiple definitions of initiation and methods of measurement applied in studies, with different time frames used to identify prescribing and dispensing events. 5In this issue of Polish Archives of Internal Medicine (Pol Arch Intern Med), Kardas et al 7 aimed to address this lack of research on medication initiation and analyze the extent of primary nonadherence in Poland. The recent implementation of a nationwide eHealth system in Poland and the introduction of electronic prescriptions (e -prescriptions) enabled primary nonadherence (initiation) to be measured through the comparison of e -prescription rates to dispension rates for 47 drugs from 6 major therapeutic areas (diabetes, antithrombotic agents, cardiovascular system, lipid modifying agents, anti -invectives for systemic use, psychoanaleptics). In line with previous research, primary nonadherence was defined as an e -prescription not being dispensed within a period of 30 days. 6 In total, out of 119 880 e -prescriptions issued in Poland in 2018, 24 967 e -prescriptions were not dispensed, resulting in a primary nonadherence rate of 20.8%.Similar to studies on the prevalence of nonadherence, much of the research to date on the risk factors associated with poor adherence has focused on the implementation and discontinuation components of the taxonomy. 8,9 A systematic review of the psychosocial and behavioral factors Hippocrates (400 BC) was the first to note that some patients do not take their prescribed medicines and many later complain that the treatment does not help. 1 Since then the World Health Organisation (WHO) has called nonadherence to medication "a worldwide problem of striking magnitude" and "one of the 2 largest unsolved gaps in healthcare" (the other being suboptimal prescription of medication). 2 In the past few decades, new and efficacious medications with positive benefit -to -risk profiles have been developed and we have seen an increased focus on improving health outcomes for people and reducing costs (eg, reducing healthcare utilization). 1 However, we have made less progress in monitoring and improving adherence to medication.Recently, a taxonomy of adherence has been developed in an effort to standardize adherence--related terminology for clinical and research use and to enable benchmarking of existing adherence enhancing strategies at the European level. 3 The taxonomy defines medication adherence "as the process by which patients take t...