(P-414) Utilization of Drugs Reimbursed by the Italian Healthcare Service for the Treatment of COVID19 During the First Pandemic Wave: Gender Differences in the General and Nursing Home Population of Tuscany

Background: During the first pandemic wave (March-April 2020), the Italian Medicines Agency granted the reimbursement for the off-label prescription of hydroxychloroquine (HCQ), azithromycin (AZ) and low-molecular-weight heparin (LMWH) to treat COVID19 patients.

Objectives: To describe the use of HCQ, AZ and LMWH by gender in the general and nursing home population of Tuscany.

Methods: A descriptive, drug utilization study was performed linking the population-based Regional Administrative Database (RAD) of Tuscany to the regional COVID19 registry. Subjects registered in RAD at 1 December 2019 with >6 months of look-back period were selected. New users of HCQ, AZ and LMWH were respectively identified in each month of the observation period (December 2019-May 2020). New users were subjects with ≥1 dispensing during the month of interest and none in the previous 6 months. The distribution of new users per month was observed both in the general and nursing home population. The percentage of subjects recorded as positive to COVID-19 before starting the drug of interest was also described. Results were stratified by male (M) and female (F) gender. Indication for drug use was not available.

Results: New users observed in the general and in the nursing home population were 5115 and 66 for HZQ, 101505 and 314 for AZI, 75176 and 1308 for LMWH, respectively. As for the general population, HZQ new users (M=601; F=1238) increased over 3-fold in April compared to February, AZ use appeared not affected, while LMWH new users showed a negative peak in April (M=3848; F=5879). The percentage of COVID19+ new users in April was M=25% and F=27% for HZQ, M=3% and F=5% for AZI, M=9% and F=8% for LMWH. As for nursing homes, over 90% of HZQ new users started the drug in April (M=21; F=42); AZ new users in April (M=37; F=84) were two-fold compared to February; LMWH new users showed a peak in April (M=88; F=153). COVID19+ new users in April were M=57% and F=64% for HZQ, M=32% and F=37% for AZI, M=31% and F=35% for LMWH.

Conclusions: During the first pandemic wave, a higher number of female new users of HCQ, AZI and LMWH was observed particularly in the nursing home population due to gender differences in age distribution and COVID19 epidemiology. A high increase of HCQ new users was observed. Particularly in the general population, HCQ was often started before having COVID19 test results or even for prophylactic use. Overall LMWH new users decreased due to the postponement of surgical interventions in the general population. In nursing homes, AZ was probably preferred over other antibiotics independently from test results.