Table 1.
Characteristics of the included studies
| Author (year), larger project if applicable | Country of study (country of participants) | Study design | Number of participants | Customer type/price paid | FU duration | Demographic characteristics of the study population | Post-test contact | The same study population as | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Bloss et al. (2011b), SGHI | USA | Longitudinal observational study | 2037 | Not real/reduced RRP | 3 months | 55.3% female Mean age (range) = 47 (19–85) 84.2% White Median education level category: some postgraduate education Median income category = $100,000–$149,000 |
Online report Pro-active genetic counselling outreach by Navigenics; initially only for specific subgroups, later all customers |
Bloss et al. (2013), Boeldt et al. (2015), Darst (2013) and Darst et al. (2013) | Participants were employees from health and technology companies who were offered the regular Navigenics Health Compassa at a reduced rate |
| Bloss et al. (2013), SGHI | USA | Longitudinal observational study | 1325 | Not real/reduced RRP | 1 year | 60.2% female Mean age (range) = 48 (19–84) 84.9% Caucasian Median education category: some post-college education Median income category = $100,000–$149,000 |
See Bloss et al. (2011b) | Bloss et al. (2011b), Boeldt et al. (2015) and Darst et al. (2013) | |
| Boeldt et al. (2015), SGHI | USA | Longitudinal observational study | 2037 | Not real/reduced RRP | 3 months | 55% female Mean age (range) = 47 (19–85) 84% Caucasian Median education category: some post-college education Median income category = $100,000–$149,000 |
See Bloss et al. (2011b) | Bloss et al. (2011b, 2013)) and Darst et al. (2013) | |
| Carere et al. (2016), Pgen study | USA | Longitudinal observational study | 998 | Real/full RRP | 6 months | 59.9% female Mean age (range) = 47 (19–94) 85.8% White Predominant education category: Some graduate school (36.0%) Predominant income category = <100,000 (56.0%) |
Standard procedures of genetic testing companies | van der Wouden et al. (2016)and Olfson et al. (2016) | New customers of 23andMea and Pathway genomicsa |
| Darst et al. (2013), SGHI | USA | Longitudinal observational study | 1325 | Not real/reduced RRP | 14 months | 55.6% female Mean age (range) = 51 (23–75) 85.6% Caucasian Modal education category: master’s degree (25%) Median income category = $150,000–$199,999 (15%) |
See Bloss et al. (2011a, b) | Bloss et al. (2011a, 2013), Boeldt et al. (2015)and Darst et al. (2014) | |
| Darst et al. (2014), SGHI | USA | Longitudinal observational study | 2024 | Not real/reduced RRP | 6 months |
Sharers: 57% female Mean age (range) = 50 (20–85) 84.6% Caucasian Median education category: some post-college Median income category = $150,000–$199,999 Non-sharers: 54.6% female Mean age (range) = 45 (19–81) 84.0% Caucasian Median education category: some post-college Median income category = $100,000–$149,999 |
See Bloss et al. (2011a) | Bloss et al. (2011b,, 2013), Boeldt et al. (2015)and Darst et al. (2013) | |
| Egglestone et al. (2013) | USA (71.8%), UK (9.4%), Canada (6.6%), Australia (3.9%), other (8.3%) | Cross-sectional study | 189 | Real/full RRP | Different per participant (no range reported) | 37% female Predominant age category = 30–44 (58%) 84.2% Caucasian Predominant education category: postgraduate degree (55.3%) |
Standard procedures of genetic testing companies | None | Data included in our study is restricted to actual consumers (excluding potential consumers, as reported) Participants included customers of 9 different DTC-GT companiesa |
| Gordon et al. (2012), CPMC | USA | Qualitative cross-sectional study | 60 | Not real/free | At least 3 months | 60% female Average age = 48.9 68% Caucasian Predominant education category: college degree or more (60%) |
Online report, with additional educational material offered online and in educational sessions | None | Data included in our study is the quantitative data reported by the authors The genetic testing is offered through the study for coronary artery disease, type 2 diabetes, haemochromatosis, prostate cancer, melanoma, age-related macular degeneration, and lupus. Other non-genetic factors are included to calculate risk estimates |
| Haga et al. (2014) | USA | Randomised intervention study | 300 | Not real/free | 1 week | 27% female Predominant age category = 18–29 (44%) 68% White Predominant education category: bachelor’s degree or higher (72%) |
Online only or printed and communicated in person, depending on randomised condition | None | Non-diabetic participants from the general public were randomized to receive their type 2 diabetes mellitus genetic testing results in person from a certified genetic counsellor or access them online through a secure website. Testing was done through deCODEa |
| James et al. (2011) | USA | Randomised intervention study | 150 | Not real/free | 1 week and 1 year | 28% female Predominant age category = 60–69 (47%) Predominant education category: graduate or professional school (47%) |
Online report prior to planned appointment with physician. Genetic counselling from Navigenics had been offered, but none of the participants had requested this | None | Participants were recruited from a prevention clinic and received a free modified version of standard test of Navigenicsa, including only “actionable” diseases (abdominal aneurysm, atrial fibrillation, breast cancer (women only), celiac disease, colon cancer, type 2 diabetes mellitus, Graves’ disease, myocardial infarction, lung cancer, obesity, osteoarthritis and prostate cancer (men only)). The intervention group received the genetic testing in addition to their usual care preventive medicine appointment. They were granted access to the result 1 week before their scheduled preventive medicine appointment. The control group received usual care only, including a wide range of examinations based on medical and family history, physiological examinations and screening tests |
| Kaphingst et al. (2012), MI | USA | Longitudinal observational study | 199 | Not real/free | 3 months | 57% female Mean age (SD) = 35 (4.2) 62% White Predominant education category: college degree or higher (52%) |
Mailed report. Participants were contacted within 10 days by a research educator who further explained results, and participants could ask questions | Reid (2012) and O’Neill (2015) | Participants, selected from a large health maintenance organization, received free health screening for 8 common health conditions (diabetes, osteoporosis, heart disease, colon cancer, high cholesterol, lung cancer, high blood pressure and skin cancer) |
| Kaufman et al. (2012) | USA | Cross-sectional study | 1046 | Real/full RRP | 2–7 months | 46% female Predominant age category = 55–74 (42%) 87% White Predominant education category: postgraduate (54%) Predominant income category = >$125,000 (45%) |
Standard procedures of genetic testing companies | None | Includes participants from three genetic testing companies (Navigenicsa, 23andMea and deCODEmea), approached through email |
| Lee et al. (2013) | NR | Cross-sectional study | 80 | Real/full RRP | Different per participant (no range reported) | 50.0% female Mean age (range) = 44 (23–72) 80.3% White Predominant education category = 4-year college graduate (33.3%) Predominant household income category = <$50.000 (31.6%) |
Standard procedures of genetic testing companies | None | Online survey among 23andMea customers, administered following an in-depth interview. Information about the study was published in the blog that is emailed directly to 23andMe customers |
| McGrath et al. (2016) | USA | Cross-sectional study | 122 | Real/full RRP | Not reported | 32.8% female Mean age (range) = 34 (19–71) Predominant education category: master’s degree or higher (38.5%) Median income = $90,000 |
Standard procedures of genetic testing companies | None | Online survey administered to 23andMea customers |
| McGuire et al. (2009) | USA | Cross-sectional study | 63 | Real/full RRP | Different per participant (no range reported) | 59% female Predominant age category = 25–34 (38%) 77% Caucasian Predominant education category: bachelor’s degree (36%) |
Standard procedures of genetic testing companies | None | Survey administered to general population. Data included is only on participants who “did use” personal genetic testinga |
| Olfson et al. (2016), Pgen | USA | Longitudinal prospective cohort study | 1464 | Real/full RRP | 6 months | 61% female Mean age (range) = 44 (23–72) 90% White College degree or more advanced education = 78% Mean household income category = $70,000–$99,999 |
Carere et al. (2016) | Carere et al. (2016)and van der Wouden et al. (2016) | |
| O’Neill et al. (2015), MI | USA | Longitudinal observational study | 228 | Not real/free | 10 days | 56.6% female Mean age (SD) = 35 (4.2) 62.3% non-Hispanic White Predominant education category: college or more (67.1%) |
See Kaphingst et al. (2012) | Kaphingst et al. (2012)and Reid et al. (2012) | |
| Reid et al. (2012), MI | USA | Longitudinal observational study | 1599 | Not real/free | Comparing health care use 12 months prior and post testing | 59.0% female Predominant age category = 35–40 (61.3%) 61.3% White Predominant education category: college graduate (51.2%) |
See Kaphingst et al. (2012) | Kaphingst et al. (2012)and O’Neill et al. (2015) | |
| van der Wouden et al. (2016), Pgen | USA | Longitudinal prospective cohort study | 1026 | Real/full RRP | 6 months | 39.7% female Mean ages = 45–51 85.1% White Predominant education category: some graduate school (35.5%) Predominant income category = $100,000–$199,999 (30.3%) |
See Carere et al. (2016) | Carere et al. (2016)and Olfson et al. (2016) |
CPMC Coriell Personalized Medicine Collaborative, FU follow-up, MI multiplex initiative, NR not reported, Pgen Impact of Personal Genomics study, RRP regular retail price, SGHI Scripps Genomic Health Initiative
aRefers to commercially available services