Table 1.

 Comparison of health and sexuality measures used in national survey of midlife development in the United States (MIDUS) and national social life, health and ageing project (NSHAP)

Characteristic	MIDUS (1995-6)	NSHAP (2005-6)
Age range (years)	25-74	57-85
Self reported physical health	“Would you say your health is excellent, very good, good, fair, or poor?”	“Would you say your health is excellent, very good, good, fair, or poor?”
Partnership	Respondents who were married or cohabiting at time of survey, even if they were not sexually active, were defined as having a partner	Respondents who were married or cohabiting at time of survey, even if they were not sexually active, were defined as having a partner
Sexual activity	Respondents who had had sex with at least one partner in previous six months were considered to be sexually active	Respondents who had had sex with at least one partner in previous 12 months were considered to be sexually active*
Frequency of sex	“Over the past six months, on average, how often have you had sex with someone?” Responses ranged from: “never or not at all” to “two or more times a week.” Respondents having sex 2-3 times a month or more were defined as having sex regularly	“During the last 12 months, about how often did you have sex with [partner]?” Responses ranged from “once a month or less” to “once a day or more.” Respondents having sex 2-3 times a month or more were defined as having sex regularly
Quality of sex life:
Positive physical quality	NA	“How physically pleasurable did/do you find your relationship with [partner] to be: extremely pleasurable, very pleasurable, moderately pleasurable, slightly pleasurable, or not at all pleasurable?” Individuals who reported their most recent relationship to be extremely or very pleasurable were defined as having a good quality of physical sexual life
Positive emotional quality	NA	“How emotionally satisfying did/do you find your relationship with [partner]: extremely satisfying, very satisfying, moderately satisfying, slightly satisfying, or not at all satisfying?” Individuals who reported their most recent relationship to be extremely or very satisfying were defined as having a good quality of emotional sexual life
Overall good quality	“How would you rate the sexual aspect of your life these days?” Responses ranged from 0, “the worst possible situation,” to 10, “the best possible situation.” Individuals with a rating of ≥6 were considered to have an overall good quality of sexual life	Individuals having good quality of both physical and emotional components of sexual life were considered to have an overall good quality of sexual life
Interest in sex	“How much thought and effort do you put into the sexual aspect of your life?” Responses ranged from 0, “none,” to 10, “very much.” Respondents with rating of ≥6 were considered to be interested in sex	Estimated using the following question: “About how often do you think about sex?” with six variants ranging from “never” to “several times a day.” Respondents who reported thinking about sex “one to a few times a week” or more were considered to be interested in sex

*A 12 month, rather than 6 month, time frame was used in consideration of older age of NSHAP population, and for comparability to only other comprehensive, nationally representative study of adult sexuality in the United States.¹²