This study used two nationally representative, population based cohorts to deepen an understanding of the relation between health and sexuality in middle and later life and to project population estimates of sexually active life expectancy, a new measure to quantify expectations about future sexual life. Using two datasets, the study affirmed a positive association between later life health and both sexual partnership and any sexual activity. In addition, a consistently strong association was found between good health and other domains of sexuality not previously linked to health in later life, including the frequency of sexual activity (weekly or more often) in men, a good quality sex life, and a higher interest in sex. Sexual activity, a good quality sex life, and interest in sex were higher for men than for women and this gender gap widened with age. Sexually active life expectancy was longer for men, but men lost more years of sexually active life as a result of poor health than women.
Partnership drives sexual activity, particularly in later life. Between 70% and 80% of men across all age groups reported having a partner, compared with 67.5% of women aged 25-54 and fewer than 40% of women aged 75 and older. This finding reflects the longer life span of women, the age structure of marriage in the United States and other countries whereby men tend to marry younger women, and the higher proportion of older men with much younger partners.1 27 28
As found by others, men and women with partners in middle and later life were equally likely to be sexually active, but the frequency of sexual activity declined across age groups for women more than for men.29
Many sexually active people in this study rated the quality of their sex life as less than good, including about half of sexually active older women. Particularly little has been known about the quality of older women’s sexual lives.
Sexually active life expectancy was calculated as a function of gender and health. Overall, the study found that men live a significantly greater proportion of their adult life as sexually active (due at least in part to more years of partnership than women) yet lose significantly more years of sexually active life as a result of poor health than do women. This resonates with findings from a previous analysis using the NSHAP dataset, showing that men’s physical health problems were most commonly cited by both sexes as the reason for sexual inactivity in later life.1
The stronger association between sexually active life expectancy and health found in men may be explained in part by the effects of common chronic illnesses (for example, diabetes, cardiovascular disease, prostate cancer) and their treatments on erectile function.30 31 32 33 34
Loss of erectile function diminishes or prohibits penetrative intercourse and is often accompanied by a decline in or cessation of a man’s sexual activity and sexual satisfaction.35 36
In contrast, the effects of illness or drug use on sexual function in women are poorly understood. Sexual problems, including low desire, vaginal dryness, difficulties with orgasm, and pain with intercourse are prevalent among sexually active older women,1
are associated with decreased sexual satisfaction,35
but typically do not render a woman physically incapable of sexual intercourse. Women’s sexual interest or motivation may be more resilient to illness or sexual problems than men’s,37
may be more contextually dependent on the partner or situational factors,38
or, as seen in younger populations, older women may have less agency over their sexual activity than men.38
Interest in sex among women of the same age in the two nationally representative cohorts surveyed 10 years apart was relatively stable. In contrast, significantly more men aged 57-64 in the later life cohort reported an interest in sex than men of the same age surveyed 10 years earlier. This was true for men with and without a partner in both cohorts and corroborates a positive secular trend in attitudes about sex found among older men surveyed 30 years apart in a 2001 study of 70 year olds in Gothenburg, Sweden.28
The difference may partly reflect the introduction of the highly effective and widely promoted male erectile dysfunction drugs to the US and European markets, beginning with sildenafil in 1998.39 40
More than 14% of US men surveyed in 2005-6 by NSHAP reported that they had taken prescription or non-prescription drugs or supplements to improve sexual function in the previous 12 months.1
With this secular increase in sexual interest among older men, the gender gap in later life interest in sex has also increased: among men aged 57-64 with partners, 76.7% reported an interest in sex compared with 35.9% of women with partners (only 12% of women without partners compared with 68% of men without partners were interested). Consistent with this finding, sexually active life expectancy at age 55 was longer for men surveyed in 2005-6 compared with men surveyed 10 years earlier (4.8 months longer overall, 12 months longer for men with partners), and increased only for women with a partner (7.2 month increase).
Strengths and limitations of the study
Although the data were collected by separate research groups using different sexuality measures, the use of two generally comparable population based probability samples for these analyses shows external validity of the study findings and made it possible to create the new sexually active life expectancy measure. Prevalence estimates for partnership, sexual activity, sexual frequency, and good quality sex life were highly consistent when the overlapping age groups in the two studies were compared and are consistent with previous findings for men41
and younger women.42 43
In addition, use of the two datasets allowed examination of secular trends in various aspects of sexuality measured 10 years apart. Comparison with the 1971 and 2001 Swedish studies of 70 year olds provides additional evidence of external validity of the cross sectional and secular trend findings. For example, the 2001 Swedish study found similar frequencies of sexual activity and satisfaction among women with and without partners as found in the 2005-6 US cohort. These frequencies were higher than those found in the 1995-6 US cohort of 65-74 year olds and notably higher than in the1971 Swedish cohort of 70 year olds.28
Longitudinal data are needed to determine whether regular sexual activity, a good sex life, or high sexual interest promote health or whether good health promotes these positive sexual attributes; this study relies on cross sectional data. In addition, measures of sexuality were not identical in the two studies (table 1). NSHAP used a 12 month time frame to define currently “sexually active” people, whereas MIDUS used a six month time frame. This difference could result in a relative overestimate of the prevalence of sexual activity in the NSHAP cohort, although prevalence for the overlapping age groups in the two studies was nearly identical. Both studies included both regular and casual or intermittent partners in these definitions, limiting comparisons between various kinds of sexual relationships. Interpretation of comparisons across the two studies must also take into account differences in the wording of some questions, such as those pertaining to quality of sex life and sexual interest. Although overall non-response to items was low in both surveys, older respondents and women were more likely than others to refuse to answer questions on sexuality. It is unclear from previous research whether such refusals would tend to underestimate or overestimate sexual activity in these groups.44 45
Because of the study population, these findings may be limited in relevance to lesbian, gay, and other people who do not identify as heterosexual, and to non-Western cultures. Further research is needed; the public availability of the instruments used for NSHAP and MIDUS provides an opportunity for adaptation of this research to other communities.
The calculation of the sexually active life expectancy measures used the Sullivan method, which generally provides a good measure of the current composition of a population but is not based on transition rates between sexually active and non-active states.46
The Sullivan method has been shown to produce estimates of health expectancy comparable to more advanced multistate approaches for populations with smooth and gradual changes in disability and morbidity, as is the case in the US population.47
Similarly, the distribution of sexual activity by age group across the two cohorts surveyed 10 years apart was noticeably similar. In this study we assumed the same mortality for people with different health and partnership statuses. This assumption might underestimate sexually active life expectancy for those with very good or excellent health or for those with a partner and might overestimate sexually active life expectancy for those with poor or fair health owing to the possibility of differential survival among people with different health statuses and partnership.48 49
Our analytical approach used official life tables to predict mortality accurately but was limited by the lack of accessible and reliable age and gender specific estimates of survival by health and partnership status.
Conclusions and policy implications
Sexual partnership, frequency of sexual activity, a good quality sex life, and interest in sex are positively associated with health among middle aged and older adults in the United States. Interest in sex among middle aged and older men in the United States has increased since 2000. Overall, the study found that men have a longer sexually active life expectancy and that most sexually active men report a good quality sex life. In contrast, only about half of sexually active women reported a good quality sex life. This disparity, and its implication for health, requires further exploration.
Men lose more years of sexually active life as a result of poor health than women. The estimation of sexually active life expectancy is a new life expectancy tool that can be used for projecting public health and patient needs in the arena of sexual health. Projecting the population patterns of sexual activity in later life is useful for anticipating need for public health resources, expertise, and medical services. Translation of expectations about the duration and quality of sexually active life may, at the individual level, influence important health behaviours to promote or prolong sexual functioning, such as adherence to medical treatment or maintenance of a healthy lifestyle. One study found that parents of children with cancer exhibited different medical decision making and healthcare utilisation when they had more accurate expectations of their child’s life expectancy.50
Further research is needed to evaluate the potential impact of sexually active life expectancy projection on individual health behaviour.
What is already known on this topic
- Many older people are sexually active
- Partnership and sexual activity have been positively associated with health in middle age and later life
- Knowledge about patterns of sexual activity in the population informs public health policy and patient education and counselling
What this study adds
- Frequency of sexual activity, a good quality sex life, and interest in sex are positively associated with health in middle age and later life
- Interest in sex among middle aged and older men in the United States has increased since 2000
- About half of sexually active older women report a poor quality sex life
- At age 55, sexually active life expectancy is 15 years for men and 10.6 years for women; although the period is longer for men, they lose more years of sexually active life as a result of poor health than women