DOI: 10.3886/icpsr38173.v1
title: San Francisco Young Men's Health Study, 1992-1999
title: Version 1

description: The San Francisco Young Men's Health Study (SFYMHS) was a prospective epidemiological study, designed to learn more about the natural history of Acquired Immune Deficiency Syndrome (AIDS). The participants were from a sample of young men aged 18 to 29 who resided in 21 census tracts in San Francisco. These participants took part in a baseline survey in order to obtain information about behavior, attitudes, and beliefs relevant to AIDS. They were also asked to give a specimen of blood for serologic testing. This study had two major objectives: (1) to determine the general health status of young men living in San Francisco, and (2) to determine the degree to which this population was at risk for HIV infection. In addition, the study provided estimates of the prevalence of HIV infection among young gay and bisexual men. Five annual follow-up surveys were carried out in order to monitor the trends in these variables. 
 During Wave 2 of the Young Men's Health Study, the original participants were asked to complete a second interview and provide another blood specimen. In addition, these original participants were asked to volunteer the names of their gay and bisexual friends who might be interested in taking part in the study. This secondary group, recruited between May 1993 and January 1994, is referred to as the Referral or Snowball sample. This group was also asked to participate in an interview and provide a blood sample. Beginning with Wave 3 of the main Original sample, the Referral sample was re-interviewed together with the Original sample. Wave 3 of the Original sample is combined with Wave 2 of the Referral sample, Wave 4 of the Original sample was combined with Wave 3 of the Referral sample, and so on until Wave 6 of the Original sample, which was combined with Wave 5 of the Referral sample. 
 Beginning with Wave 4 of the Original sample, the Host Genetics Sub-Study was started. Wave 1 of this sub-study shows the results for 91 members of the SFYMHS who were selected to be part of the Host Genetics Sub-Study. Some 38 gay or bisexual men from the Original Random sample participated, and 53 gay or bisexual men from the Referral sample were also chosen. All were interviewed in person between June 1995 and May 1996. There were three additional waves of the Host Genetics Sub-Study. Wave 1 of this sub-study corresponds to Wave 4 of the Original sample, Wave 2 corresponds to Wave 5 of the Original sample, and Wave 3 corresponds to Wave 6 of the Original sample. Wave 4 of the Host Genetics Sub-Study included the results for 64 members of the Original Sample who still participated in the Host Genetics Sub-Study. Some 30 gay or bisexual men from the Original Random Sample participated, and 34 gay or bisexual men from the Referral sample participated. All were interviewed for the last time between January 1999 and October 1999.
description: This study had two major objectives: to determine the general health status of young men living in San Francisco during the time of the study, and to determine the degree to which this population is at risk for HIV infection. In addition, this study sought to provide estimates of the prevalence of HIV infection among young gay and bisexual men. 
 A secondary objective of this study was to gain understanding of the level of knowledge about and feelings towards participation in HIV vaccine trials from participants.
description: A letter was sent to each selected housing unit to introduce the study in general terms and to advise residents that an interviewer would be coming. Shortly thereafter, an interviewer went to the household to determine whether any persons eligible for the study resided there. If one or more eligible persons were found, they were given information packets on the study and, if possible, were immediately given appointments for a visit to the clinic, where the interview and examination would be administered. Several visits were made to each household, if needed, in order to locate eligible persons and to schedule clinic appointments. Prior to each scheduled clinic appointment a reminder postcard was sent, and an attempt was made to confirm the appointment by telephone on the day before.
 The second phase of this project involved re-contacting the 381 gay and bisexual participants from the baseline survey who had completed the interview and provided a blood specimen. These participants were re-interviewed and asked to provided another blood specimen. In addition, these original study participants were asked to volunteer the names of gay and bisexual friends who might be interested in taking part in the study. Of 354 original respondents interviewed in Wave 2, a total of 225 provided one or more referrals. These referrals, in turn, were also asked to volunteer names of persons who might be interested taking part in the study. There were a total of 622 gay and bisexual men recruited in this manner, including a few who heard about the study and volunteered on their own to participate. The participants who were recruited through this process are referred to as the Referral or Snowball Sample.
description: The San Francisco Young Men's Health Study contains 11 total parts that are composed of waves from the Original Sample, Referral Sample, and the Host Genetics Sub-Study. The main variables in these parts include information on participant's medical history, medical insurance, sexual history, recreational drug use, attitudes towards vaccines, relationship status, and demographic information. 
The Host Genetics Sub-Study included in this study contains the same aforementioned variables as well as immunophenotyping data from participants 
 Waves 4 through 6 of the Original Sample and Waves 3 through 5 of the Referral Sample include variables that contain information on participation in AIDS volunteer groups and community meetings, as well as immunophenotyping data.
description: The probability that a specific housing unit would fall
into the Original sample was not the same in every census tract and block. To compensate for unequal probabilities of selection, a sampling weight inversely proportional to those
probabilities was created. For more information on weighting procedures see the technical sampling report. Note that the Referral Sample has a missing-data code on the weight variable.
description: Response Rates: Of 6,671 selected households for the Wave 1 randomly selected baseline study, 495 were vacant or had no one who was English speaking. Of the remaining 6,176 households, screening interviews were completed at 5,801 households, for a screening response rate of 93.9 percent. The screening process identified 997 households with 1,356 eligible males. Of the 1,356 eligible males, wave 1 interviews were completed with 1,076 (79.4 percent). The combined response rate was therefore (.939 x .794) = 74.6 percent.
description: The sample for this survey was a stratified single stage area sample of all households within 21 census tracts in the city of San Francisco, California. Each tract was treated as a sampling stratum. The tracts included were: 162-171, 202-207, and 210-214. All eligible males in each selected housing unit were taken into the initial sample for at least a brief interview. The full interview was completed with 428 men who identified as gay or bisexual. Of the 428 randomly selected gay or bisexual men, 208 responded to the final Wave 6 self-administered questionnaire in 1997-1998. 
 During Wave 2, the randomly selected study participants were asked to volunteer the names of their gay and bisexual friends who might be interested in taking part in the study. This secondary group, including a few self-selected volunteers, were also requested to suggest additional gay and bisexual friends. This supplementary sample, recruited between May 1993 and January 1994, was referred to as the Referral or Snowball Sample. This group was also asked to participate in an interview and provide a blood sample. There were 622 men in this Referral Sample. After their initial interview, members of the Referral Sample were interviewed four additional times together with the members of the Original sample. Among those in the Referral Sample, 368 responded to the final self-administered questionnaire in 1997-1998.
description: Datasets: 
DS0: Study-Level Files
DS1: Original Random Sample Wave 1 Data
DS2: Original Random Sample Wave 2 Data
DS3: Referral Sample Wave 1 Data
DS4: Original Random Sample Wave 3 and Referral Sample Wave 2 Data
DS5: Original Random Sample Wave 4 and Referral Sample Wave 3 Data
DS6: Original Random Sample Wave 5 and Referral Sample Wave 4 Data
DS7: Original Random Sample Wave 6 and Referral Sample Wave 5 Data
DS8: Host and Genetics Sub-Study Wave 1 Data
DS9: Host and Genetics Sub-Study Wave 2 Data
DS10: Host and Genetics Sub-Study Wave 3 Data
DS11: Host and Genetics Sub-Study Wave 4 Data
description: English speaking men, currently unmarried, aged 18-29 from 21 census tracts in San Francisco. Smallest Geographic Unit: Census Tracts
description: face-to-face interview; mail questionnaire; telephone interview