Methods


BACKGROUND

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

  1. Stanton E: The Human Development Index: a History. Political Economy Research Institute, University of Massachusetts at Amherst, USA; 2007
  2. Bhanojirao V: Human development report 1990: review and assessment. World Develop 1991, 19(10):1451-1460.
  3. United Health Foundation: America's Health Rankings: a Call to Action for Individuals and Their Communities. 2011 ed. Minnetonka, Minnesota, USA: UHF
  4. OEC/JRC European Commission: Handbook on Constructing Composite Indicators: Methodology and User Guide. Paris, France: OEC/JRC; 2008
  5. Downs M: Sexual Health Rankings: a Composite Index and Ranking of Sexual Health in the United States—50 States and the District of Columbia. Technical Report. December 2012. Lebanon, New Hampshire, USA: Variance, LLC; 2012
  6. Downs M, Dobson D: Sexual Health Rankings 2013: multivariate analysis of sexual health indicators and composite ranking of the 50 US States. Working Paper. Lebanon, New Hampshire, USA: Variance, LLC; 2014

DEFINING SEXUAL HEALTH

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.

WHO, 2006

Elements of Sexual Health

For the purpose of constructing this composite index, we have condensed the WHO definition into five fundamental elements:

  1. Ability of individuals to have control over, and freely decide on, their own sexual behavior and experiences
  2. Ability of individuals to decide freely on whether, and when, to procreate
  3. Freedom from discrimination and violence related to sexuality and gender
  4. Experience of sexual pleasure and satisfaction
  5. Freedom from sexual morbidity, including HIV/AIDS and other sexually transmitted infections.

SEXUAL HEALTH INDICATORS

Indicator Categories

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

  1. Laws, policies, and human rights
  2. Education
  3. Society and culture
  4. Economics
  5. Health systems.

This theoretical framework provided the basis for selecting individual indicators to include in the composite index.

Third Edition Indicators

Category Domain Indicator Element(s) of Sexual Health
Outcomes Reproductive teen birth rate Autonomy, Reproductive Choice
Outcomes Sexual Satisfaction % of adults married or a member of an unmarried couple Pleasure/satisfaction
Outcomes Sexual Satisfaction % of adults reported health status good or better Pleasure/satisfaction
Outcomes Sexual Violence forcible rape rate Autonomy, Discrimination/violence
Outcomes Sexually Transmitted Infections cervical cancer rate Morbidity
Outcomes Sexually Transmitted Infections gonorrhea rate Morbidity
Outcomes Sexually Transmitted Infections HIV rate Morbidity
Outcomes Sexually Transmitted Infections syphilis rate Morbidity
Factors Education % of high schools in which teachers taught essential condom use topics in a required course Autonomy, Reproductive Choice, Morbidity
Factors Education/Laws, Policies & Human Rights state mandates sex education in schools Reproductive Choice, Morbidity
Factors Education/Laws, Policies & Human Rights State mandates STI/HIV education in schools Reproductive Choice, Morbidity
Factors Education/Laws, Policies & Human Rights State mandates STI/HIV education in schools must cover contraception Reproductive Choice, Morbidity
Factors Health Systems % of teen girls received >=3 doses of HPV vaccine Morbidity
Factors Health Systems % of adults ever tested for HIV Morbidity
Factors Laws, Policies & Human Rights state allows same-sex marriage Autonomy, Discrimination/violence
Factors Laws, Policies & Human Rights state law addresses hate crimes based on sexual orientation and/or gender identity Autonomy, Discrimination/violence
Factors Laws, Policies & Human Rights state law bans employment discrimination based on sexual orientation and/or gender identity Autonomy, Discrimination/violence
Factors Laws, Policies & Human Rights state law bans housing discrimination based sexual orientation and/or gender identity Autonomy, Discrimination/violence
Factors Laws, Policies & Human Rights state public employee health insurance plans restrict abortion coverage Autonomy, Reproductive Choice, Discrimination/violence
Factors Laws, Policies & Human Rights state restricts private health insurance coverage of abortion Autonomy, Reproductive Choice, Discrimination/violence
Factors Laws, Policies & Human Rights state health insurance exchanges restrict abortion coverage Autonomy, Reproductive Choice
Factors Laws, Policies & Human Rights state mandates private health insurance coverage of contraceptives Autonomy, Reproductive Choice
Factors Laws, Policies & Human Rights employers may refuse to provide health insurance coverage of contraceptives Autonomy, Reproductive Choice
Factors Laws, Policies & Human Rights insurers may refuse to provide health insurance coverage of contraceptives Autonomy, Reproductive Choice
Factors Society & Culture % of seats in state legislature held by women Discrimination/violence
Factors Society & Culture % of women with high school diploma or higher education Autonomy, Reproductive Choice, Discrimination/violence, Pleasure/satisfaction, Morbidity

Indicator Selection Criteria

We evaluated potential indicators systematically, using predetermined criteria based on standards developed for the International Monetary Fund General Data Dissemination System.3 These standards are not specific to health indicators, but are considered broadly applicable to health-related data collection and dissemination. The three main criteria are relevance, availability, and data quality.

Relevance
An indicator had to be relevant to the concept of sexual health as defined in the theoretical framework and relevance had to be supported by scientific evidence. Relevance was determined by mapping an indicator's relation to the 5 elements of sexual health, with literature reviews conducted to document evidence supporting these relationships.
Availability
Selection is limited to indicators for which state-level analyses of data are available in published reports or public datasets. All indicator data used in the analysis are publicly available secondary data.
Data quality
We adapted the International Monetary Fund Data Quality Assessment Framework to establish criteria for evaluating the quality of indicator data.4

We considered four aspects of data quality: integrity, accuracy, timeliness, and consistency.

Integrity
Indicator data collection, analysis, and reporting practices must be objective, transparent, and adherent to professional and ethical principles.
Accuracy
Data must be collected and analyzed using sound statistical techniques, and must sufficiently portray reality. Data must have been evaluated for accuracy by the organization responsible for their collection, analysis, and dissemination. Detailed documentation of metadata must be readily available. Indicators should include complete data for all 50 states. We avoided imputation of missing values if it was possible to use older data within the allowed time frame, if multiyear data could be combined to obtain a state value when single-year data were suppressed due to small sample sizes, or if another comparable indicator with complete data could be used.
Timeliness
Timeliness refers to the time frame that an indicator covered and the frequency with which data were reported. The limits imposed on timeliness are influenced by data availability for some indicators. We limited selection to indicators with available single-year data no earlier than 2010, and chose the latest available single-year data. Combining multiple years of data is sometimes necessary to increase sample sizes for small populations and uncommon outcomes. Multiple consecutive years of data may be combined for a pooled analysis, which estimates the average value of the indicator over that time period. We included indicators based on multiyear data for which the latest available year was 2010 or later, and the earliest year in the pooled analysis was 2006 or later. We prefer data published on an annual basis.
Consistency
Data must be consistent within the dataset, over time, and with major datasets. The organization producing the data must have addressed geographic differences in the way variables were defined and recorded, as well as other issues that could affect comparisons between states.
  1. World Health Organization/Special Programme of Research, Development and Research Training in Sexual Reproduction/Dept of Reproductive Health and Research: Developing Sexual Health Programmes: A Framework for Action. Geneva, Switzerland: WHO/HRP/RHR; 2010
  2. Health Metrics Network: Framework and Standards for Country Health Information Systems. 2nd ed. Geneva, Switzerland: WHO; 2008
  3. International Monetary Fund: Data Quality Assessment Framework—Generic Framework (July 2003). Washington, DC, USA: IMF; 2006

DIMENSIONS OF SEXUAL HEALTH

We used an analytical technique called "factor analysis for mixed data"1 to reduce the full set of 26 sexual health indicators to a smaller set of composite variables (dimensions).2 The analysis shows that two dimensions account for most of the variance in sexual health among the 50 states. The first dimension (social & policy) accounts for 33%, and second dimension (health status) accounts for 19%.

The 15 indicators that are significantly associated with each dimension contribute to a state's composite score on that dimension. Indicators that are not significantly associated with either dimension do not contribute to the composite scores, and do not influence the rankings.

The first and second dimension scores are added together to produce an overall sexual health score for each state. The 50 states are ranked from best to worst by their overall score, with the no. 1 rank going to the state with the highest score.

The highest-ranking states score highly on both dimensions. The lowest-ranking states have low scores for both dimensions.

Indicator Correlations With Sexual Health Dimensions

Quantitative Indicators: Direction & Strength of Association

  1. Pagès J: Analyse factorielle multiple appliquée aux variables qualitatives et aux données mixtes. Rev Statist Appl 2002, 50(4):5-37
  2. Husson F, Josse J, Le S, Mazet J: Package 'FactoMineR'. The Comprehensive R Archive Network; February 19, 2015