Sexual health is increasingly understood as a multidimensional concept encompassing all aspects of sexuality. Measurement of sexual health at the population level has not kept pace with the evolution of the concept of sexual health. Various population health indicators capture some, but not all, discrete aspects of sexual health, and the lack of common units of measurement makes interrelationships among indicators difficult to analyze and interpret.
A composite indicator or index (CI) can be used to summarize a multidimensional concept by mathematically combining numerous individual indicators. A CI provides a framework to facilitate analysis of many disparate indicators related to a large, complex concept, and a means to compare—typically by ranking or grading—the performances of entities or population groups (e.g., countries, states, colleges, and companies). Composite indicators are widely used as scientific and public policy instruments.
The methodologic foundations of CIs were laid within the field of development economics. In the 1960s, economists became interested in creating an index of human well-being by combining various indicators reflecting "both the means and ends of social progress." 1 The United Nations (UN) and the Organization for Economic Cooperation and Development (OECD) led important efforts to construct this type of CI, culminating in the UN Development Program's Human Development Index, which was introduced in 1990.2 Work on a CI of human well-being inspired and informed development of CIs by researchers in other fields, including public health. America's Health Rankings, also introduced in 1990, applied these advanced econometric methods to construct a CI of overall health in the United States.3 The OECD has formalized the study of CIs and continues to address the methodologic challenges involved in their construction and use. In 2008, the OECD and the Joint Research Center of the European Commission jointly published the Handbook on Constructing Composite Indicators: Methodology and User Guide, a comprehensive review of methods and best practices.4
Prior to our effort, no one had applied these methods to the broad concept of sexual health as defined by WHO. The following sections describe the methodology used to construct the third edition of our CI of sexual health in the United States, for the year 2014. The results and methodology of the first (2012) and second (2013) editions of Sexual Health Rankings were published independently on this Web site.5,6
Sexual Health Rankings is based on a holistic, positive concept of sexual health, first advanced by the World Health Organization (WHO), that is widely accepted by authorities in the health and social sciences.
WHO defines sexual health as:
"... a state of physical, emotional, mental and social well-being in relation to sexuality; it is not merely the absence of disease, dysfunction or infirmity. Sexual health requires a positive and respectful approach to sexuality and sexual relationships, as well as the possibility of having pleasurable and safe sexual experiences, free of coercion, discrimination and violence. For sexual health to be attained and maintained, the sexual rights of all persons must be respected, protected and fulfilled."
WHO, 2006 Defining Sexual Health: Report of a Technical Consultation on Sexual Health, 28–31 January 2002, Geneva
WHO further defines the terms "sexuality" and "sexual rights" as follows:
SEXUALITY is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviours, practices, roles and relationships. While sexuality can include all of these dimensions, not all of them are always experienced or expressed. Sexuality is influenced by the interaction of biological, psychological, social, economic, political, cultural, ethical, legal, historical, religious and spiritual factors.
SEXUAL RIGHTS embrace human rights that are already recognized in national laws, international human rights documents and other consensus statements. They include the right of all persons, free of coercion, discrimination and violence, to:
- the highest attainable standard of sexual health, including access to sexual and reproductive health care services; seek, receive and impart information related to sexuality;
- sexuality education;
- respect for bodily integrity;
- choose their partner;
- decide to be sexually active or not;
- consensual sexual relations;
- consensual marriage;
- decide whether or not, and when, to have children; and
- pursue a satisfying, safe and pleasurable sexual life.
The responsible exercise of human rights requires that all persons respect the rights of others.
For the purpose of constructing this composite index, we have condensed the WHO definition into five fundamental elements:
We identified indicator categories that measure these elements of sexual health. Adapted from WHO recommendations on country-level indicators of sexual health,1 these categories were broadly classified as "outcomes" and "factors." We defined outcomes as measures of health status and impact. Factors are conditions, or social determinants, that influence sexual health.
We grouped sexual health factors into the following subcategories, corresponding to five "key domains" of sexual health, as defined in a 2010 WHO framework for sexual health programs.2
This theoretical framework provided the basis for selecting individual indicators to include in the composite index.