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Biomedical subjects

Charles F Turner

Publications and source records attributed to Charles F Turner.

8 recordsLinked to original sources
PubMed2005

Polymerase chain reaction detection of Y chromosome sequences in vaginal fluid: preliminary studies of a potential biomarker for sexual behavior.

BACKGROUND: Self-reported measures of sexual behavior are subject to nontrivial reporting biases. OBJECTIVE: The objective of this study was to develop a behavioral biomarker of recent sexual activity among females that is inexpensive, easily administered, and can be used in low sexually transmitted disease prevalence populations. METHODS: We developed a polymerase chain reaction (PCR) assay to detect Y chromosome (Yc) fragments. The Yc primers were developed against a 200-basepair (bp) microsatellite repeat sequence, which is unique to the male genome. A standard PCR technique was used. Assay sensitivity was determined quantitatively using donated semen samples. To assess longevity of detectability, we recruited female subjects in monogamous relationships. Seventeen subjects had unprotected intercourse followed by 3 weeks of abstinence from vaginal intercourse. Self-administered vaginal swabs (SAVS) were collected every other day. In addition to the swabs, subjects kept daily sexual diaries. Swabs were processed by semiquantitative PCR, and Yc decay curves were determined for each subject. The half-life of Yc in vaginal fluid was calculated on the collection of individual decay curves by a random-effects regression model approach. RESULTS: The sensitivity of our Yc-PCR assay was determined to be 5 copies of Yc. In the longevity studies, Yc was detectable in SAVS up to 15 postcoital days (PCD). Mean Yc DNA concentration in SAVS eluate followed an exponential decay pattern for each subject. Mean concentrations were 66.7 ng/mL at PCD-1, 20.6 ng/mL at PCD-7, and 4.5 ng/mL at PCD-15. The estimated half-life for Yc clearance was 3.83 days. CONCLUSION: The swab-based Yc-DNA PCR assay can detect coitus in women for a 2-week retrospective period. This can be used to validate sexual behavior-reporting and condom use in women and promises to be a useful tool in sexual behavior research.

Adult↗
PubMed2005

Reducing bias in telephone survey estimates of the prevalence of drug use: a randomized trial of telephone audio-CASI.

AIM: To assess the impact of telephone audio computer-assisted self-interviewing (T-ACASI) on reporting of alcohol use, alcohol problems and illicit drug use in telephone surveys of the general population. Prior research suggests that illicit drug use is underreported in traditional, interviewer-administered, telephone surveys. DESIGN: Randomized experiment embedded in telephone survey of probability samples of populations of USA and Baltimore, MD. Survey respondents were randomly assigned to be interviewed either by human telephone interviewers or by T-ACASI after household screening, recruitment, and informed consent procedures were completed. SETTING: Respondents were interviewed by telephone in their homes. PARTICIPANTS: Probability samples of 1543 English-speaking adults ages 18-45 residing in telephone-accessible households in USA and 744 similarly defined adults residing in Baltimore, MD, USA. MEASUREMENTS: Nine questions on alcohol, marijuana, cocaine, and injection drug use adapted from 1994 NHSDA and four CAGE questions on alcohol problems. Crude odds ratios and odds ratios controlling for demographic factors calculated to test for differences between responses obtained by T-ACASI and human interviewers. FINDINGS: T-ACASI had mixed effects on reporting of alcohol use, but it did increase reporting of one of four CAGE alcohol problems: feeling guilty about drinking (23.0% in T-ACASI vs. 17.6% in T-IAQ, OR = 1.4, P < 0.01). T-ACASI also obtained significantly more frequent reporting of marijuana, cocaine, and injection drug use. The impact of T-ACASI was most pronounced for reporting of recent use of 'harder' drugs. Thus T-ACASI respondents were more likely to report marijuana use in the past month (10.0% vs. 5.7%, crude OR = 1.9, P < 0.001), cocaine use in the past month (2.1% vs. 0.7%, crude 3.2, P < 0.001) and injection drug use in the past five years (1.6% vs. 0.3%, crude OR = 4.8, P < 0.01). CONCLUSIONS: Telephone survey respondents were more likely to report illicit drug use and one alcohol problem when interviewed by T-ACASI rather than by human telephone interviews.

Adolescent↗
PubMed2004

Audio-computerized self-interviewing versus face-to-face interviewing for research data collection at drug abuse treatment programs.

AIMS: To assess audio computer-assisted self-interviewing (A-CASI) as a mode of data collection with injecting drug users (IDUs) entering two drug treatment programs in New York City. A-CASI has been found to increase reporting of sensitive items among a variety of population subgroups. DESIGN: A field test of A-CASI data collection conducted within an ongoing cross-sectional study of drug use and HIV risk behaviors among IDUs entering drug treatment. Participants were assigned without bias to either a computer-assisted interviewer-administered personal interview (CAPI) or to a mixed CAPI/A-CASI interview. In the latter, 'sensitive' portions (dealing with stigmatized behavior) of the questionnaire were self-administered through A-CASI, while the remaining portions were interviewer-administered. SETTING: The Detoxification Program and the Methadone Maintenance Treatment Program (MMTP) at Beth Israel Medical Center in New York City. PARTICIPANTS: Seven hundred and eighty-three IDUs entering drug treatment. MEASUREMENTS: Odds ratios and adjusted odds ratios (controlling for demographic differences) for comparison of A-CASI versus CAPI responses on 111 sensitive questions. FINDINGS: Twenty-three statistically significant differences (each at P < 0.05), all in the direction of more reporting of the behaviors by the A-CASI group. Forty-one per cent of A-CASI participants said they would prefer any subsequent interviews to be fully A-CASI and 46% said they would prefer the mixed CAPI/A-CASI mode. CONCLUSIONS: A-CASI was associated with greater reporting of potentially stigmatized drug, sex and HIV risk behaviors on a moderate number of questions. Moreover, a large majority of participants who used A-CASI would like to be assigned to this method of data collection in future interviews.

Adult↗
PubMed2002

Untreated gonococcal and chlamydial infection in a probability sample of adults.

CONTEXT: The prevalence and distribution of gonococcal and chlamydial infections in the general population are poorly understood. Development of nucleic acid amplification tests, such as the ligase chain reaction assay, provides new opportunities to estimate the prevalence of untreated infections in the population. OBJECTIVE: To estimate the overall prevalence of untreated gonococcal and chlamydial infections and to describe patterns of infection within specific demographic subgroups of the young adult population in Baltimore, Md. DESIGN AND SETTING: Cross-sectional behavioral survey based on a probability sample of Baltimore households with collection of urine specimens between January 1997 and September 1998. PARTICIPANTS: A total of 728 adults aged 18 to 35 years completed the interview portion of the study, and 579 of these respondents also provided a urine specimen adequate for testing. MAIN OUTCOME MEASURE: Prevalence of untreated infection, as measured by the percentage of specimens testing positive for gonococcal and chlamydial infection by ligase chain reaction, weighted to reflect variations in probabilities of sample selection from the population. Alternate estimates of the prevalence of recent treated infection were derived from clinically diagnosed cases reported to the Baltimore City Health Department and by diagnoses reported by participants in the survey. RESULTS: An estimated 5.3% (SE, 1.4%) of the population aged 18 to 35 years has an untreated gonococcal infection, and 3.0% (SE, 0.8%) is estimated to have an untreated chlamydial infection. While 7.9% (SE, 1.6%) of the population is estimated to have either an untreated gonococcal or chlamydial infection, estimated prevalence is substantially higher among black women (15.0%; SE, 3.7%). Few participants with untreated infections reported dysuria or discharge during the 6 months preceding testing. The estimated number of untreated gonococcal infections in the population (9241; SE, 2441) substantially exceeds both the number of such infections diagnosed among Baltimore adults aged 18 to 35 years and reported to the Baltimore City Health Department during 1998 (4566), and the estimated number of diagnoses derived using participants' reports for the 12 months prior to the survey (4708 [SE, 1918] to 5231 [SE, 2092]). The estimated number of untreated chlamydial infections (5231; SE, 1395) is also greater than the number of cases reported to the health department in 1998 (3664) but is slightly less than the estimated number of diagnoses derived using participants' reports of chlamydial infections diagnosed during the 12 months prior to the survey (5580 [SE, 1918] to 6975 [SE, 2441]). CONCLUSION: In 1997-1998, the estimated number of undiagnosed gonococcal and chlamydial infections prevalent in the population of Baltimore adults aged 18 to 35 years approached or exceeded the number of infections that were diagnosed and treated annually.

Adult↗
PubMed2002

NAAT-identified and self-reported gonorrhea and chlamydial infections: different at-risk population subgroups?

BACKGROUND: Information on the characteristics and behaviors of persons at high risk for gonorrhea and chlamydial infection has typically been derived from studies of sexually transmitted disease (STD) clinic populations. The Baltimore STD and Behavior Survey (BSBS) used urine-based nucleic acid amplification testing (NAAT) to assess the prevalence and behavioral correlates of gonorrhea and chlamydial infection in a population-based cross-sectional survey of adults in Baltimore, Maryland. GOAL: The goal of this study was to examine the demographic characteristics and behavioral markers of gonorrhea and chlamydial infection as reported by adults with a self-reported history of gonorrhea and chlamydial infection and to compare these to the characteristics and behaviors of individuals with current NAAT-identified gonorrhea and/or chlamydial infection. STUDY DESIGN: A probability sample of adults aged 18 to 35 years residing in Baltimore was evaluated with collection of urine specimens and administration of a health and behavior survey. Data and specimens were collected between January 1997 and September 1998. RESULTS: Respondents with NAAT-detected gonorrhea and/or chlamydial infection (7.9%) did not report a history of high-risk behaviors or more recent occurrences of those behaviors, and the majority were asymptomatic. However, adults in our study who self-reported a history of infection (26.0%) were more likely than those with no history of infection to report multiple partners, paid sex, partners with prior STDs, and STD symptoms-a pattern consistent with findings described in previous clinic-based reports. CONCLUSION: The risk profile generated from studies of clinic populations, with a focus on symptomatic disease, may not characterize the broader population with current, untreated, largely asymptomatic infection.

Adolescent↗
PubMed2002

The differential effects of face-to-face and computer interview modes.

OBJECTIVES: This study assessed the differential effects of face-to-face interviewing and audio-computer assisted self-interviewing (audio-CASI) on categories of questions. METHODS: Syringe exchange program participants (n = 1417) completed face-to-face interviews or audio-CASI. The questionnaire was categorized into the groups "stigmatized behaviors," "neutral behaviors," and "psychological distress." Interview modes were compared for questions from each category. RESULTS: Audio-CASI elicited more frequent reporting of "stigmatized behaviors" than face-to-face interviews. Face-to-face interviewing elicited more frequent reporting of "psychological distress" than audio-CASI. CONCLUSIONS: Responding to potentially sensitive questions should not be seen as merely "providing data," but rather as an activity with complex motivations. These motivations can include maintaining social respect, obtaining social support, and altruism. Ideally, procedures for collecting self-report data would maximize altruistic motivation while accommodating the other motives.

Adult↗
PubMed2002

Risk behaviors, medical care, and chlamydial infection among young men in the United States.

OBJECTIVES: This study assessed factors related to chlamydial infection among young men in the United States. METHODS: Data were from interviews of nationally representative samples of 470 men aged 18 to 19 years (teenagers) and 995 men aged 22 to 26 years (young adults) and from urine specimens tested by means of polymerase chain reaction. RESULTS: Although a majority of the men reported occasional unprotected intercourse, only a minority perceived themselves to be at risk for contracting a sexually transmitted disease (STD). Chlamydial infection was detected in 3.1% of the teenagers and 4.5% of the young adults. A minority of those infected had symptoms or had been tested for STDs; very few had been diagnosed with STDs. CONCLUSIONS: Chlamydial infection is common but usually asymptomatic and undiagnosed. Primary and secondary prevention efforts should be increased, particularly among young adult men.

Adolescent↗