Table 1.
Characteristics of included studies
| First author (year) | Survey method, exposure | Population, setting, country | Sexual orientation/behaviour question | Comparison | Recruitment, data collection | Outcomes of interest* | Study design, funding |
| Mortality studies | |||||||
| Frisch (2013) | National demographic data from Danish Civil Registration System, including mortality data. | Population, marriage, living in same-sex or opposite-sex cohabitation for at least 1 year between 1982 and 2011. Denmark. |
Cohabitation record, marriage record (same-sex marriage from 1989) (NB: 75.6% same-sex cohabiting women were same-sex married). | Opposite-sex cohabitation, marriage | National demographic data collection | Mortality | Population cohort. Supported by—NR |
| Surveys based on multistate BRFSS | |||||||
| Blosnich (2013) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults in partnerships. All states, USA. |
Various similar in the 10 states with response options heterosexual or straight; homosexual, gay or lesbian; bisexual; other; and opposite or same-sex partner. | Opposite-sex partnered women | BRFSS for all US states, 2004 | Current asthma, lifetime asthma | Population survey. Supported by a National Research Service award. |
| Blosnich (2014) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults. Alaska, Arizona, California, Maine, Massachusetts, Montana, New Mexico, North Dakota, Washington, Wisconsin, USA. |
Various similar in the 10 states with response options heterosexual or straight; homosexual, gay or lesbian; bisexual; other. | Heterosexual women | BRFSS for 10 states, 2010 | CVD symptoms, asthma, diabetes | Population survey. Supported by National Research Service awards. |
| Surveys based on single-state BRFSS | |||||||
| Conron (2010) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking, Spanish-speaking or Portuguese-speaking non-institutionalised adults. Massachusetts, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual; or D something else? (D answers excluded). | Heterosexual women | Massachusetts BRFSS 2001–2008 | Heart disease, diabetes, asthma | Population survey. Supported by Massachusetts Department of Public Health HIV/AIDS Bureau and Ford Foundation. |
| Garland-Forshee (2014) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults. Oregon, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual or D other? (D answers excluded). | Heterosexual women | Oregon BRFSS 2005–2008 | Cardiovascular disease, hypertension, diabetes, asthma | Population survey. Supported by Center for Disease Control grants. |
| Matthews (2014) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults. North Carolina, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual; or D other? (D answers excluded). | Heterosexual women | North Carolina BRFSS 2011 | Angina or heart disease, hypertension, diabetes, asthma | Population survey. Supported by National Institute for Mental Health grant. |
| Dilley (2010) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults. Washington, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual; or D something else? (D answers excluded). | Heterosexual women | Washington State 2003–2006 | Diabetes, hypertension, (asthma) | Population survey. Supported by Washington State Tobacco Prevention and Control Program and BRFSS. |
| Fredriksen-Goldsen (2012) |
Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults. Washington, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual; or D something else? (D answers excluded). | Heterosexual women | Washington State BRFSS 2003–2009 | Asthma | Population survey. Supported by NIH and National Institute on Aging grants. |
| Fredriksen-Goldsen (2013) | Telephone-based (landline) random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
English-speaking or Spanish-speaking non-institutionalised adults aged over 50. Washington, USA. |
A heterosexual or straight; B homosexual, gay or lesbian; C bisexual; or D something else? (D answers excluded). | Heterosexual women aged over 50 | Washington State BRFSS 2003–2010 | Cardiovascular disease (asthma, diabetes, hypertension) | Population survey. Supported by National Institute on Aging grant. |
| Studies based on other US national or state surveys | |||||||
| Jackson (2016) and Ward (2015) |
Inperson interviews using cluster-based probability sampling. Had ever been told by a health professional that they had (a named condition), or diagnosed by a doctor (CVD). |
Non-institutionalised adults. USA. |
Straight (not lesbian or gay); gay or lesbian; bisexual; something else? (something else answers excluded). | Straight women | National Health Interview Survey 2013–2014 | Diabetes, heart disease (CHD or any other kind of heart disease, angina pectoris or a myocardial infarction), stroke, hypertension, asthma (Ward) | Population survey. Supported by several grants including from Harvard Catalyst and NIH. |
| Kann (2016) | School questionnaire-based survey, nationally representative data. Had ever been told by a doctor or nurse that they had asthma. |
Students in grades 9–12 (aged 14–18) attending high schools USA. |
Which of the following best describes you? ‘heterosexual (straight)’, ‘gay or lesbian’, ‘bisexual’ or ‘not sure’ AND During your life, with whom have you had sexual contact? ‘I have never had sexual contact’, ‘females’, ‘males’, and ‘females and males’. |
Heterosexual female students AND sexual contact with males. |
Youth Risk Behavior Surveillance System | Lifetime asthma | Population survey. Supported by the Centers for Disease Control and Prevention. |
| Boehmer (2014) | Telephone-based random digit-dialled interview. Had ever been told by a health professional that they had (a named condition). |
Adults aged over 20 with telephone and living in California. | Identified as heterosexual; gay or lesbian; bisexual (excluded celibate and non-sexual responses). | Heterosexual women | California Health Interview Survey 2001–2007 | Heart disease, hypertension, hypertensive medication, diabetes, asthma | Population survey. Supported by—NR. |
| Wallace (2011) | Telephone-based survey. Question NR. |
Lesbian and bisexual women aged 50–70. | NR | Heterosexual women aged 50–70 | California Health Interview Surveys 2003–2007 | (Heart disease, hypertension, diabetes) | Population survey. Supported by California Wellness Foundation. |
| Farmer (2013) | Inhome survey. Had ever been told by a health professional that they had diabetes or sugar diabetes, responded yes to currently taking antihypertensives. |
Adults aged 20–69 who completed the sexual behaviour survey. National, USA. |
Do you think of yourself as heterosexual or straight (attracted only to men); homosexual or lesbian (sexually attracted only to women); bisexual (sexually attracted to men and women); something else or not sure. | Heterosexual women | National Health and Nutrition Examination Survey 2001–2008 | Diabetes, antihypertensive medication | National population survey. Supported by National Institute on Drug Abuse and National Institute on Alcohol Use and Alcoholism grants. |
| Studies based on single waves of cohort studies | |||||||
| Everett (2013) and Clark (2015) |
Interviewer collected hypertension results (Everett 2013) and diabetes from fasting blood glucose sample, non-fasting glucose sample, HbA1c, or self-report health provider diagnosis or use of antidiabetic medication in previous 4 weeks (Clark 2015). | Follow-up 10–15 years after, from sample recruited originally through schools. National, USA. |
100% heterosexual (straight); mostly heterosexual (straight) but somewhat attracted to people of your own sex; bisexual—attracted to males and females equally; mostly homosexual (gay) but somewhat attracted to people of the opposite sex; 100% homosexual (gay). | 100% heterosexual women | Wave IV of the National Longitudinal Study of Adolescent Health 2007–2008 | Everett 2013—hypertension of >140 SBP and >90 DBP. Clark 2015—diabetes (and antihypertensive medication). |
National population cohort. Supported by Eunice Kennedy Shriver National Institute of Child Health and Human Development grant (Everett 2013) and National Center for Advancing Translational Sciences grant (Clark 2015). |
| McNair (2011) | Self-completion questionnaire. Had been diagnosed or treated for a range of illnesses over the previous 3 years. |
Original sample aged 18–23 selected randomly from database of Medicare Australia. | Exclusively heterosexual, mainly heterosexual, bisexual, mainly homosexual (lesbian). | Exclusively heterosexual women | Third survey of the young cohort of women in the Australian Longitudinal Study on Women’s Health 2003 | Asthma | National population cohort. Supported by Lesbian Health Fund, USA. |
*Outcomes in brackets were reported in included study texts but not used in the systematic review due to elimination of duplicate reporting.
BRFSS, Behavioral Risk Factor Surveillance System; CVD, cardiovascular disease; DBP, diastolic blood pressure; HbA1c, haemoglobin A1c; NR, not reported; SBP, systolic blood pressure.