Подскажите, пожалуйста, что здесь обозначает legend duration of prescription? Длительность применения назначенного рецептурного препарата или что-то другое?

The extent of the heterogeneity of drug utilization among NSAID users has not been extensively studied. We studied the longitudinal prescribing and switching patterns of NSAID users in a 1-year follow-up study in four German pharmacies. The study population consisted of 526 persons with an average age of 57 years. We observed that the legend duration of prescription increased with age; 14.3 days for patients aged 44 or younger to 25.1 days for persons 75 years or older, and was dependent on disease chronicity; 16.0 days for acutely ill persons compared to 23.9 days for chronic patients. The average legend duration also varied between different types of NSAIDs, from 18.0 days for ibuprofen to 29.1 days for tiaprofen.

https://pubmed.ncbi.nlm.nih.gov/15073777/

Заранее спасибо.