Three Decades of Change in Frequency of Sexual Intercourse and Sexual Function Among Japanese Men: A Comparative National Survey

ABSTRACT Objective This study aimed to examine trends in frequency of sexual intercourse and sexual function among Japanese men over the past 30 years by comparing the Nationwide Survey conducted by the Japanese Society for Sexual Medicine in 2023 with the Sapporo Survey conducted by the Department of Urology, Sapporo Medical University, in 1991. Methods Three domains were analyzed: sexual intercourse, penile rigidity, and morning erections in both studies. To minimize inconsistencies, definitions were standardized. The 2023 survey included 3795 men aged 20–79 years, while the 1991 survey comprised 8893 participants for sexual intercourse, 7517 for morning erections, and 3886 for penile rigidity. Case numbers differed by item in 1991 owing to incomplete responses. The 1991 survey targeted only married individuals; comparable analyses were performed using married participants extracted from the 2023 dataset. Results 1. Sexual intercourse: Compared with the 1991 Sapporo Survey, the proportion of men reporting sexual intercourse less than once per month was significantly higher across all age groups in the 2023 Nationwide Survey, except among men in their 20s. 2. Penile rigidity: The proportion of men with insufficient penile rigidity for penetration was significantly higher in 2023 than in 1991 across all age groups except those aged ≥ 75 years. 3. Morning erections: Men reporting complete absence of morning erections were significantly more common in 2023 across all age groups. Conclusion Over the past three decades, Japanese men have shown substantial declines in the frequency of sexual intercourse, penile rigidity, and the frequency of morning erections, particularly in younger and middle‐aged cohorts.