Objective
To estimate the increase in sales of emergency contraception following the New Year’s Eve/New Year’s Day holiday.
Design
Time series analysis using autoregressive integrated moving average (ARIMA) model.
Setting
Traditional (that is, “bricks and mortar”) retail outlets—grocery stores, drug stores, mass merchandisers, club stores, dollar stores, and military outlets—in the United States from 2016 to 2022.
Data source
Marketing data on weekly aggregated sales of items classified as emergency contraception gathered between 2016 and 2022 (n=362). On the basis of dates, weeks were classified as following the New Year holiday (n=6) or not (n=356).
Main outcome measure
Weekly sales of levonorgestrel emergency contraception per 1000 women of reproductive age in the US population.
Results
Sales of levonorgestrel emergency contraception significantly increased after the New Year holiday (0.63 (95% confidence interval 0.58 to 0.69) unit increase per 1000 women aged 15-44). Holidays that share some aspects of the elevated risks of unprotected sexual intercourse with the New Year holiday (Valentine’s Day, St Patrick’s Day, US Independence Day) were associated with increased sales, albeit to a lesser degree, with respective sales increases per 1000 women aged 15-44 of 0.31 (0.25 to 0.38), 0.14 (0.06 to 0.23), and 0.20 (0.11 to 0.29). Holidays without these expectations (Easter, Mother’s Day, Father’s Day) were not significantly associated with sales of levonorgestrel emergency contraception.
Conclusions
Increased sales of emergency contraception following the New Year’s holiday suggest that this period is associated with increased risks of unprotected vaginal intercourse compared with other holidays. Targeting behavioral risks, prevention strategies to mitigate sexual violence, and improving access to contraception around holidays may limit the risks associated with unprotected vaginal intercourse.