Our study was based on the SWELL study, a multicenter cross-sectional survey conducted between June 2020 and December 2022. The survey spanned four different regions in China, including Shanghai (Eastern China), Jinan (Eastern China), Chongqing (Western China), Guangzhou (Southern China), and Tianjin (Northern China). Participants were recruited using a multistage sampling design, and more detailed sampling procedures are provided in our previous protocol [26]. We collected data on demographic characteristics, physical health characteristics, mental health characteristics, sex partner relationship characteristics, and sexual behavior characteristics through face-to-face interviews. All participants provide formal informed consent to participate in the study.

Participants were enlisted from subdistricts within each chosen city. Eligibility criteria for participants in this study included: (1) aged 50 years and older; (2) only heterosexual orientation; (3) having engaged in heterosexual activities (including oral or vaginal intercourse) in the preceding year; (4) being able to comprehend the survey instrument of the SWELL Study.

The SWELL study was approved by the School of Public Health (Shenzhen), Sun Yat-sen University Research Ethics Committee (approval number SYSU-PHS [2019] 006) and was performed following the Helsinki Declaration. Written consent was obtained from all participants, who were informed of their right to withdraw from the study at any time. Participant information and responses remained confidential, with anonymized data stored in password-protected folders accessible exclusively to the research team and supervisors.

Sexual satisfaction was measured on a 5-point Likert scale, with responses ranging from 1 to 5 (strongly agree, agree, medium, disagree, and strongly disagree). In this study, we reclassified scores of 1‐3 as sexual satisfaction and scores of 4‐5 as sexual dissatisfaction [30].

Descriptive analyses were conducted to characterize the study sample, including presenting percentages, means, and SD. The χ² test was used to compare the proportions of characteristics between the sex groups.

For the multivariable logistic regression analysis, collinearity diagnostics were initially performed for all potential variables (Multimedia Appendices 1 and 2). Subsequently, multivariate logistic regression analysis was carried out for noncollinear variables. The multivariable logistic regression models selected variables using a stepwise method based on the Akaike Information Criterion (AIC). The stepwise regression method combines forward selection and backward elimination approaches, adding and removing predictors in the model-building process. This approach effectively minimizes the inclusion of covariates, thereby enhancing the robustness of the analysis. Finally, the model with the minimum AIC was adopted (men: 1005.929; women: 582.316). Adjusted odds ratios (aORs) and their corresponding 95% CIs were estimated.

All statistical analyses were performed using R software version 4.2.3 (R Project). The Stats package (version 4.2.2) was used to build the stepwise multivariable logistic regression models. In addition, the figures were generated using the ggplot2 package (version 3.4.3) and forestmodel package (version 0.6.2) from CRAN.

As shown in Table 1, 1317 older adults were included in this analysis. The average age was 64 years (SD 8.4 years, ranging from 50 to 86 years). Over half of the participants resided in rural areas (men: 53.1% [447/842], women: 50.9% [242/475]), and the majority reported 7‐12 years of education (junior or senior high school; men: 70.0% [589/842], women: 59.6% [283/475]). In addition, a significant proportion of participants reported infrequent engagement in physical exercise (men: 54.8% [461/842], women: 48.2% [229/475]). Regarding physical health, more than half of the participants did not frequently experience fatigue (men: 85% [716/842], women: 74.9% [356/475]) and did not have chronic diseases (men: 55.2% [465/842], women: 62.9% [299/475]). Regarding sexual relationship characteristics, the majority of male participants reported sexual satisfaction (479/842, 56.9%) and a good relationship with their sex partner (615/842, 73.0%). In comparison, women reported slightly lower rates of sexual satisfaction (228/475, 48.0%) and a good relationship with their sex partner (306/475, 64.4%). Furthermore, less than 5.1% (24/475) of both men and women reported symptoms of anxiety and depression.

The prevalence of at least one sexual response problem (including or excluding lack of interest in sex) is shown in Figure 1 and Table 2. In total, 610 out of 1317 participants had sexual response problems, with an overall prevalence of sexual response problems of 46.3% (610/1317). There was a significant difference in the prevalence of the reported at least one sexual response problem between women and men, with being significantly higher in women than in men (52.0% [247/475] vs 43.1% [363/842], χ²₁=9.6, P=.002). The prevalence of at least one sexual response problem increased with age among men (The Cochran-Armitage Trend Test, Z=−2.476, P for trend=.01). However, this trend was only observed in the age group between the older than 70 years age group and the other 2 age groups among men. There was no significant difference in the prevalence of sexual response problems between the 60‐69 years age group and the 50‐59 age group among women.

The results of multivariable logistic regression analysis stratified by sex, which was presented in Figure 2, revealed several significant associations with reporting at least one sexual response problem.

For older men, residing in rural areas (aOR 0.31, 95% CI 0.22‐0.43) and maintaining an emotional connection with a sex partner during sexual intercourse (aOR 0.69, 95% CI 0.50‐0.96) were associated with a reduced likelihood of reporting sexual response problems. In contrast, being 70 years or older (aOR 1.72, 95% CI 1.05‐2.81), frequently experiencing fatigue (aOR 2.47, 95% CI 1.59‐3.90), and poor sleeping quality (aOR 1.87, 95% CI 1.30‐2.68) were associated with higher odds of reporting sexual response problems. In addition, moderate to severe anxiety symptoms (aOR 4.26, 95% CI 1.12‐21.27), abnormal BMI (aOR 1.52, 95% CI 1.11‐2.07), and seeking professional help for sex issues (aOR 1.58, 95% CI 1.14‐2.21) were positively associated with reporting sexual response problems among older men.

Older women residing in rural areas (aOR 0.29, 95% CI 0.19‐0.43) were less likely to report sexual response problems. Conversely, factors such as infrequent engagement in physical exercise (aOR 1.69, 95% CI 1.13‐2.54), depressive symptoms (aOR 3.18, 95% CI 1.18‐10.24), having an abnormal BMI (aOR 2.19, 95% CI 1.47‐3.28), and being in a poor sex partner relationship (aOR 1.70, 95% CI 1.12‐2.60) were associated with higher odds of reporting sexual response problems.

Our study demonstrated a high prevalence of sexual response problems among older adults, with variations noted between men and women. In older men, sexual response problems correlate with advancing age. Our findings also linked sexual response problems with adverse physical health outcomes such as frequent experiencing fatigue, poor sleep quality, and abnormal BMI. In addition, we observed strong associations between sexual response problems and mental health issues, including anxiety and depressive symptoms. Moreover, poor sex partner relationships, sexual dissatisfaction, and lack of emotional connection during sex were also associated with sexual response problems. These findings significantly contribute to the existing literature, underscoring the importance of addressing sexual response problems within the domain of sexual health and enhancing our understanding of these issues among older adults.

In this study, women reported a higher prevalence of sexual response problems compared to men, consistent with findings from other countries [12-14]. This discrepancy may be due to several factors, including physiological alterations, psychological elements, and sociocultural dynamics. With advancing age, women experience a significant decline in estrogen levels, especially after menopause [31]. Furthermore, older women are subject to various age-related psychological changes, such as concerns about body image, fears about aging, and self-consciousness about their sexual lives, which may lead to decreased sexual desire or arousal issues. In Chinese culture, the sexual lives of older adults are frequently neglected or deemed inappropriate, which may influence the perceptions and expectations of sex among older women, making them feel ashamed or uncomfortable in their sexual lives. This sex difference highlights the need for targeted interventions for women’s sexual health. These interventions should address the multifaceted nature of sexual health in older women, combining physiological, psychological, and sociocultural interventions.

In this study, adverse physical health, such as abnormal BMI, frequent fatigue, and poor sleep quality, played a crucial role in sexual response problems. These findings were identified by evidence from high-income countries, which linked poor physical health to sexual response problems [32-34]. Obesity, characterized by an abnormal BMI, detrimentally impacts the reproductive system and sexual function [35-37]. Both men and women affected by obesity face a heightened risk of fertility challenges and sexual dysfunction [38]. Weight loss can reduce fatty tissue and diminish aromatase activity, leading to a relative increase in testosterone levels [39], which enhances sexual function in men. Besides, weight loss tends to improve sexual functioning for women and men [40]. Obesity significantly affects the hypothalamic-pituitary-gonadal axis in men, leading to diminished libido and erectile dysfunction [41]. The previous review highlighted that excess body weight negatively affected hormones contributing to sexual behavior, noting that adipose tissue facilitates the conversion of androgens to estrogens, further impacting sexual function [42]. Given the inverse association between body mass and sexual response problems, it is recommended that clinicians, both in general practice and in weight loss programs, should more fully address sexual response problems.

Poor sleep quality was associated with sexual response problems in previous studies [43,44], which was also demonstrated by this study. Poor sleep is closely linked to sexual dysfunction due to several physiological and psychological factors. Inadequate sleep can disrupt hormone production, notably reducing testosterone levels, which are essential for sexual desire and performance. Studies have shown that sleep deprivation can decrease testosterone production, leading to impaired sexual activity [45]. In addition, sleep disorders often contribute to stress, anxiety, and depression, all of which can diminish libido and sexual satisfaction [46]. Furthermore, chronic stress and anxiety can lead to sleep problems, which in turn may cause erectile dysfunction [47]. Sleep is fundamental to health, and its bidirectional relationship with sexual response difficulties necessitates that clinicians conduct thorough assessments to identify underlying causes of poor sleep, encourage patient-partner communication to alleviate psychological burdens, promote regular physical activity to enhance sleep quality, and recommend professional sleep therapy to improve physiological function when necessary.

Our study showed that lack of physical exercise was correlated with the occurrence of sex response problems among older women. Regular physical activity is a healthy practice that can mitigate the risk of sexual response problems [36,48]. These associations between sexual response problems and physical health underscore the importance of prioritizing sexual function within sexual health. Physical exercise and high-quality sleep are recommended, along with other lifestyle guidance, to improve sexual functioning in both men and women and to improve health across a range of domains.

Psychosocial factors, including symptoms of anxiety and depression, exhibited the strongest association with sexual response problems, as evidenced by findings from the Global Study of Sexual Attitudes and Behaviours (GSSAB) [49]. Other studies also linked the associations between mental health and sexual response problems, which highlighted that men with anxiety disorders are at a higher risk of developing erectile dysfunction [50,51]. Moreover, the physiological responses triggered by heightened anxiety levels may contribute to disruptions in sexual function [52]. This finding will capture the attention of practitioners exploring the causes and treatment of sexual problems in patients. In clinical practice, there should be heightened efforts to address sexual problems within integrated services of mental health and sexual health counseling, as well as in primary and secondary care.

Our findings underscored the importance of sex-partner relationships in the context of sexual response problems. Specifically, men who maintained an emotional connection with their sex partners during sex were less likely to report sex response problems, while women experiencing poor relationships with sex partners were more likely to encounter sexual response problems in older women. This underscores the role of brief emotional interactions during sexual activity in men’s adaptation to sexual response problems. In contrast, long-term sexual relationships appear to be more influential in women’s adjustment to sexual response problems. Existing studies have consistently underscored the significance of partner relationships for sexual response problems in women [53], emphasizing the impact of daily intimacies in relationships [9]. In contrast, emotional intimacy is presumed to play a significant role in maintaining sexual desire and partnered sexual activity for men [54,55]. In addition, emotional connection with a partner may foster open communication, trust, and mutual understanding, all essential to a satisfying sexual relationship. The variation in sexual response problems concerning sex partner relationships among older men and women underscores the importance of physicians considering sex differences when diagnosing and treating patients with sexual response problems. In future studies, the sex partner should be included and involved in the evaluation and management to achieve a better intimate relationship in an established couple and avoid sexual response problems.

Our study has several limitations that should be considered. First, as a cross-sectional study, it cannot establish temporal order and causal direction. Second, the reliance on self-reporting in the questionnaires, especially for sensitive issues, introduced the possibility of recall biases. Third, the sexual response problems were reported by the participants experiencing them, and the differences in the sensitivity and understanding of the same sexual problem may exist among participants, potentially influenced by factors such as education, age, or living area. Finally, some analyses were based on small cell sizes, particularly for variables like anxiety and depressive symptoms, which may result in unstable estimates.

This study showed a substantial prevalence of sexual response problems among older adults, with women experiencing these problems more often than men. The study identified adverse physical health, poor mental health, and poor relationships with sex partners as factors contributing to increased sexual response problems among older adults. To address these concerns, health care professionals can implement interventions for older adults experiencing sexual response problems, such as enhancing physical health, supporting mental health, improving intimate relationships, and providing educational and cognitive-behavioral interventions. These insights drawn from the latest and representative SWELL study data enhance our understanding of sexual response problems among older adults and have the potential to promote overall health and well-being among the aging population in China.