| No. | Study/Article | Participants | Methods | Results |
| 1. | DiStefano et al. [12] Year: 2013 Country: USA Types of study: Retrospectives | Participants: Young Adults/Parents Number: 95 Male: Not Stated Female: Not Stated Age: Not Stated | Data Collection Tools: unknown Sampling methods: unknown Place: Community based | Barriers 1. Trust 2. Religion cultural taboo 3. Fear |
| 2. | Kang et al. [37] Year: 2006 Country: USA Type of Study: Cross sectional | Participants: HIV + API Number: 44 Male: 36 Age: 31 - 60 yrs Mean Age: 44, SD: 7.94 Female: 5 Age: 36 - 67 yrs Mean age: 45, SD: 12.82 Transgender: 1 Age: 47 | Data Collection Tools: Interview Sampling Method: Non-random convenience sample Place: Community based | Barrier 1. Stigma |
| 3. | Kennedy et al. [10] Year: 2013 Country: Vanuatu Type of Study: Qualitative | Participants: Adolescents, Policy makers & service providers Number: 341 Male: 169 Female: 172 Age: 15 - 19 yrs. | Data collection Tools: Focus group, Interview Sampling Method: Purposive sample Place: Community based | Barriers 1. Culture 2. Taboos 3. Lack of confidentiality 4. Lack of Knowledge |
| 4. | Lee and Rotheram?Borus, [45] Year: 2009 Country: USA Type of study: Cohort | Participants: students Number: 13233 Female: Not Stated Male: Not Stated Age: below 14 to 18+ | Data Collection Tools: Questionnaire Sampling Methods: Random sample Place: School Based | Barriers 1. Parental communication |
| 5. | Han, [46] Year: 2009 Country: USA Type of study: Descriptive | Participants: Gay, Bisexual & Queer Asian Pacific Islander Men Number: 15 Male: 15 Female: Not stated Age 18 - 50+ | Data Collection Tools: Focus group, Interview Sampling Method: Convenience Sampling Place: Community based | Barrier 1. Racism 2. Homophobia 3. Low self esteem 4. Negative role model |
| 6. | DiStefano et al. [47] Year: 2012 Country: USA Type of study: Descriptive | Participants: Young adults, Parents, Health workers Number: 95 Female: Not Stated Male: Not Stated | Data Collection Tools: Focus group, Interview Sampling Method: Purposive Place: Community based | Barrier 1. Misinformation 2. Communication 3. Perceptions 4. Family shame 5. Privacy 6. Gender 7. Parents role 8. Religion |
| 7. | Linh et al. [48] Year: 2015 Country: Vietnam Type of Study: Case design study | Participants: Government officials, Health workers, business members, civil society leaders Number: 20 Female: Not Stated Male: Not Stated Age: Not Stated | Data Collection Tools: Interview Sampling Method: Snowball Place: Population base | Barrier 1. Cost 2. Overprotected owner rights |