1 / 19

Clinic- vs. Population-Based Studies of STD

Clinic- vs. Population-Based Studies of STD. Lisa E. Manhart 1 , Sevgi O. Aral 2 , King K. Holmes 1 , Cathy W. Critchlow 1 , James P. Hughes 1 , William L. H. Whittington 1 , Betsy Foxman 3 University of Washington, Seattle, WA 1 ; Centers for Disease Control, Atlanta, GA 2

alka
Download Presentation

Clinic- vs. Population-Based Studies of STD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Clinic- vs. Population-Based Studies of STD Lisa E. Manhart1, Sevgi O. Aral2, King K. Holmes1, Cathy W. Critchlow1, James P. Hughes1, William L. H. Whittington1, Betsy Foxman3 University of Washington, Seattle, WA1; Centers for Disease Control, Atlanta, GA2 University of Michigan, Ann Arbor, MI3

  2. Population Levels General population STD Clinic population

  3. Background • Population prevalence relatively low (CDC, 2001; NCHS) • Study populations drawn from STD clinics

  4. Sociobehavioral Risk Factors Young age at sexual debut (Aral, 1999) Unprotected intercourse(Aral, 1999) Multiple partners(Seidman, 1988) Douching (Scholes, 1993) Sexual activity level discordance (Garnett, 1996) Concurrent sex partners (Potterat, 1999) Race/age discordance (Aral, 1999) Non-white race (CDC, 2001) Low SES (Barnes, 1984)

  5. Sources of risk factor data • STD clinic studies • Population based surveys • NHANES - NSAM • NSFG - NATSAL • Add Health - DHS • Limited comparisons(Garnett, STD 1996; Johnson, STI 2002) • Lifetime number partners • Concurrent partners • Condom use patterns

  6. Methods Cross-sectional: Compare STD clinic population to RDD population Case-control: • General population case-control study to identify risk factors for gonorrhea • STD clinic case-control study to identify risk factors for gonorrhea

  7. Cross-sectional analysis RDD Survey (1995) 376 Seattle residents Age 18-39 years Random-digit-dial (RDD) telephone sample Behavioral interview, including most recent partner in past 90 days STD Clinic (1992-1995) 373 Seattle STD clinic attendees Age 18-39 years Seeking care for STD symptoms or contact to STD Behavioral interview, including most recent partner in past 90 days

  8. Cross-sectional comparison* * p<0.05 for all comparisons

  9. Sexual Behavior & Partnership Characteristics* (cross-sectional) * p<0.05 for all comparisons

  10. Case-control studiesRisk factors for gonorrhea General population* CASESCONTROLS N=103 N=376 41% from NRL† RDD resp. 59% from clinic Behavioral Behavioral survey survey * weighted logistic regression performed to account for unequal distribution of source of cases † Neisseria Reference Laboratory STD clinic* CASES CONTROLS N=61 N=332 GC diagnoses Attendees w/o GC Behavioral Behavioral survey survey * unweighted logistic regression

  11. Age (per 5 yrs) 0.4 0.5 5.4 3.1 Jail 10.5 15.5 Black 10.5 Anal sex 5.9 Hx STD 3.6 Divorced 3.2 Never use condoms 0.3 ≥HS 0.2 Structured mtg. 0.4 Income $9375-$17,499 0.08 Income >17,500 0.13 Income not reported 100 10 1.0 0.01 0.1 100 0.01 1.0 10 0.1 Factors associated with gonorrhea among heterosexuals (age 18-39) General population STD Clinic population Odds ratio (log scale) Odds ratio (log scale)

  12. Limitations • Participation bias in RDD? • RF may be specific to Seattle • Restricted age range [18-39] • No laboratory ascertainment of disease in RDD control group

  13. Conclusions • RF in STD clinic are likely to be confirmed in general population • STD clinic studies may miss some RF identified in general population • Base choice of study population on: • Question of interest • Available resources

  14. Template for OR plotGeneral Population

  15. Template for OR plotSTD Clinic Pop

  16. Age Jail Black Anal sex Hx STD Divorced Never use condoms ≥HS Structured mtg. Income $9375-$17,499 Income >17,500 Income not reported 100 10 1.0 0.01 0.1 100 0.01 1.0 10 0.1 Factors associated with gonorrhea among 18-39 year-old heterosexuals General population STD Clinic population Odds ratio (log scale) Odds ratio (log scale)

  17. STD Clinic 403 enrolled RDD Survey 544 enrolled 105 p-ship >90 days 22 out of age range 439 381 8 same-sex partner 33 not sexually active 373 406 30 same-sex partner 376

  18. Guidelines for study population selection High prevalence No stigma Low prevalence Stigma Clinic-based population General population

More Related