Yueying Zhu

Disclosure There is a statistician on the author team and her name is Yaqi Guan. The authors affirm that the methods used in the data analyses are suitably applied to their data within their study design and context and the statistical findings have been implemented and interpreted correctly. The authors agree to take responsibility for ensuring that the choice of statistical approach is appropriate and is conducted and interpreted correctly as a condition to submit to the Journal.

1 Introduction Infertility is a global health issue affecting approximately 10%–15% of couples, with significant psychological, social and economic costs [1, 2]. To achieve conception quickly, couples typically choose to have timed intercourse during the fertile window, the period with the highest likelihood of pregnancy [3]. However, a substantial proportion of women are unable to accurately identify their fertile window [4].

1. Introduction Click to copy section linkSection link copied! The opioid addiction crisis poses a significant global public health challenge, particularly in the United States, where addiction rates and overdose-related deaths have escalated in recent years. At the heart of this crisis lies opioid use disorder (OUD), a chronic relapsing condition characterized by compulsive opioid use, loss of control over drug intake, and the emergence of negative emotional states during withdrawal.