Transposon mutagenesis identifies cooperating genetic drivers during keratinocyte transformation and cutaneous squamous cell carcinoma progression.

The systematic identification of genetic events driving cellular transformation and tumor progression in the absence of a highly recurrent oncogenic driver mutation is a challenge in cutaneous oncology. In cutaneous squamous cell carcinoma (cuSCC), the high UV-induced mutational burden poses a hurdle to achieve a complete molecular landscape of this disease. Here, we utilized the Sleeping Beauty transposon mutagenesis system to statistically define drivers of keratinocyte transformation and cuSCC progression in vivo in the absence of UV-IR, and identified both known tumor suppressor genes and novel oncogenic drivers of cuSCC. Functional analysis confirms an oncogenic role for the ZMIZ genes, and tumor suppressive roles for KMT2C, CREBBP and NCOA2, in the initiation or progression of human cuSCC. Taken together, our in vivo screen demonstrates an extremely heterogeneous genetic landscape of cuSCC initiation and progression, which can be harnessed to better understand skin oncogenic etiology and prioritize therapeutic candidates.

Incarceration, high-risk sexual partnerships and sexually transmitted infections in an urban population.

OBJECTIVES: The authors examined the associations between personal and partner incarceration, high-risk sexual partnerships and biologically confirmed sexually transmitted infection (STI) in a US urban population. METHODS: Data from a probability survey of young adults 15-35 years of age in Baltimore, Maryland, USA, were analysed to assess the prevalence of personal and partner incarceration and its association with several measures of high-risk sexual partnerships including multiple partners, partner concurrency and current STI. RESULTS: A history of incarceration was common (24.1% among men and 11.3% among women). Among women with an incarcerated partner in the past year (15.3%), the risk of current STI was significantly increased (adjusted prevalence ratio=2.3, 95% CI 1.5 to 3.5). Multiple partners (5+) in the past year and partner concurrency were disproportionately high among men and women who had been incarcerated or who had sexual partner(s) or who had recently been incarcerated. These associations remained robust independent of personal socio-demographic factors and illicit drug use. CONCLUSIONS: Incarceration may contribute to STI risk by influencing engagement in high-risk behaviours and by influencing contact with partners who engage in risky behaviours and who hence have elevated risk of infection.

Chlamydia trachomatis infection among 15- to 35-year-olds in Baltimore, MD.

BACKGROUND: Chlamydia trachomatis (Ct) is the most frequently reported infectious disease in the United States. This article reports population and subpopulation prevalence estimates of Ct and correlates of infection among 15- to 35-year-olds in Baltimore, MD. METHODS: The Monitoring STIs Survey Program (MSSP) monitored sexually transmitted infection (STI) prevalence among probability samples of residents of Baltimore, a city with high STI rates. MSSP respondents completed telephone audio computer-assisted self-interviews and provided biospecimens for STI testing. RESULTS: Among 2120 Baltimore residents aged 15 to 35 years, the estimated prevalence of chlamydia was 3.9% (95% confidence interval [CI]: 2.8, 5.0). Prevalence was 5.8% (95% CI: 4.1, 7.6) among black MSSP respondents versus 0.7% (95% CI: 0.0, 1.4) among nonblack respondents; all but 4 infections detected were among black respondents. Sexual behaviors and other factors associated with infection were far more prevalent among black than nonblack Baltimore residents. Racial disparities persisted after adjustment for sociodemographic, behavioral, and health factors. CONCLUSION: The MSSP highlights a higher Ct prevalence among young people in Baltimore than in the United States overall, with notable racial disparities in infection and associated risk behaviors. Public health efforts are needed to improve the diagnosis and treatment of asymptomatic infections in this population.

Analyzing tumor heterogeneity and driver genes in single myeloid leukemia cells with SBCapSeq.

A central challenge in oncology is how to kill tumors containing heterogeneous cell populations defined by different combinations of mutated genes. Identifying these mutated genes and understanding how they cooperate requires single-cell analysis, but current single-cell analytic methods, such as PCR-based strategies or whole-exome sequencing, are biased, lack sequencing depth or are cost prohibitive. Transposon-based mutagenesis allows the identification of early cancer drivers, but current sequencing methods have limitations that prevent single-cell analysis. We report a liquid-phase, capture-based sequencing and bioinformatics pipeline, Sleeping Beauty (SB) capture hybridization sequencing (SBCapSeq), that facilitates sequencing of transposon insertion sites from single tumor cells in a SB mouse model of myeloid leukemia (ML). SBCapSeq analysis of just 26 cells from one tumor revealed the tumor's major clonal subpopulations, enabled detection of clonal insertion events not detected by other sequencing methods and led to the identification of dominant subclones, each containing a unique pair of interacting gene drivers along with three to six cooperating cancer genes with SB-driven expression changes.

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.

Gender-based screening for chlamydial infection and divergent infection trends in men and women.

OBJECTIVES: To assess the potential impact of chlamydial screening policy that recommends routine screening of women but not men. METHODS: Population surveys of probability samples of Baltimore adults aged 18 to 35 years in 1997-1998 and 2006-2009 collected biospecimens to estimate trends in undiagnosed chlamydial infection. Survey estimates are compared to surveillance data on diagnosed chlamydial infections reported to the Health Department. RESULTS: Prevalence of undiagnosed chlamydial infection among men increased from 1.6% to 4.0%, but it declined from 4.3% to 3.1% among women (p = 0.028 for test of interaction). The annual (average) number of diagnosed infections was substantially higher among women than men in both time periods and increased among both men and women. Undiagnosed infection prevalence was substantially higher among black than non-black adults (4.0% vs 1.2%, p = 0.042 in 1997-98 and 5.5% vs 0.7%, p<0.001 in 2006-09). CONCLUSION: Divergent trends in undiagnosed chlamydial infection by gender parallel divergent screening recommendations that encourage chlamydial testing for women but not for men.

Epidemiology of undiagnosed trichomoniasis in a probability sample of urban young adults.

T. vaginalis infection (trichomoniasis) is the most common curable sexually transmitted infection (STI) in the U.S. It is associated with increased HIV risk and adverse pregnancy outcomes. Trichomoniasis surveillance data do not exist for either national or local populations. The Monitoring STIs Survey Program (MSSP) collected survey data and specimens which were tested using nucleic acid amplification tests to monitor trichomoniasis and other STIs in 2006-09 among a probability sample of young adults (N = 2,936) in Baltimore, Maryland--an urban area with high rates of reported STIs. The estimated prevalence of trichomoniasis was 7.5% (95% CI 6.3, 9.1) in the overall population and 16.1% (95% CI 13.0, 19.8) among Black women. The overwhelming majority of infected men (98.5%) and women (73.3%) were asymptomatic. Infections were more common in both women (OR = 3.6, 95% CI 1.6, 8.2) and men (OR = 9.0, 95% CI 1.8, 44.3) with concurrent chlamydial infection. Trichomoniasis did not vary significantly by age for either men or women. Women with two or more partners in the past year and women with a history of personal or partner incarceration were more likely to have an infection. Overall, these results suggest that routine T vaginalis screening in populations at elevated risk of infection should be considered.

'What's in the NIDDK CDR?'--public query tools for the NIDDK central data repository.

The National Institute of Diabetes and Digestive Disease (NIDDK) Central Data Repository (CDR) is a web-enabled resource available to researchers and the general public. The CDR warehouses clinical data and study documentation from NIDDK funded research, including such landmark studies as The Diabetes Control and Complications Trial (DCCT, 1983-93) and the Epidemiology of Diabetes Interventions and Complications (EDIC, 1994-present) follow-up study which has been ongoing for more than 20 years. The CDR also houses data from over 7 million biospecimens representing 2 million subjects. To help users explore the vast amount of data stored in the NIDDK CDR, we developed a suite of search mechanisms called the public query tools (PQTs). Five individual tools are available to search data from multiple perspectives: study search, basic search, ontology search, variable summary and sample by condition. PQT enables users to search for information across studies. Users can search for data such as number of subjects, types of biospecimens and disease outcome variables without prior knowledge of the individual studies. This suite of tools will increase the use and maximize the value of the NIDDK data and biospecimen repositories as important resources for the research community. Database URL: https://www.niddkrepository.org/niddk/home.do.

The NIDDK Central Repository at 8 years--ambition, revision, use and impact.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repository makes data and biospecimens from NIDDK-funded research available to the broader scientific community. It thereby facilitates: the testing of new hypotheses without new data or biospecimen collection; pooling data across several studies to increase statistical power; and informative genetic analyses using the Repository's well-curated phenotypic data. This article describes the initial database plan for the Repository and its revision using a simpler model. Among the lessons learned were the trade-offs between the complexity of a database design and the costs in time and money of implementation; the importance of integrating consent documents into the basic design; the crucial need for linkage files that associate biospecimen IDs with the masked subject IDs used in deposited data sets; and the importance of standardized procedures to test the integrity data sets prior to distribution. The Repository is currently tracking 111 ongoing NIDDK-funded studies many of which include genotype data, and it houses over 5 million biospecimens of more than 25 types including serum, plasma, stool, urine, DNA, red blood cells, buffy coat and tissue. Repository resources have supported a range of biochemical, clinical, statistical and genetic research (188 external requests for clinical data and 31 for biospecimens have been approved or are pending). Genetic research has included GWAS, validation studies, development of methods to improve statistical power of GWAS and testing of new statistical methods for genetic research. We anticipate that the future impact of the Repository's resources on biomedical research will be enhanced by (i) cross-listing of Repository biospecimens in additional searchable databases and biobank catalogs; (ii) ongoing deployment of new applications for querying the contents of the Repository; and (iii) increased harmonization of procedures, data collection strategies, questionnaires etc. across both research studies and within the vocabularies used by different repositories.

The available pool of sex partners and risk for a current bacterial sexually transmitted infection.

PURPOSE: Sexually transmitted infection (STI) transmission models propose that incident STIs are related to exposure to infected sex partners. The objective of this study was to determine whether the prevalence of STIs among the available pool of sex partners in a neighborhood, measured indirectly, is an independent determinant of a current incident STI. METHODS: The target population comprised 58,299 English-speaking, sexually active 15- to 24-year-olds in 486 census block groups (CBGs) in Baltimore, MD. A sample of 65 CBGs was selected using a stratified, systematic, probability-proportional-to-size strategy and 13,873 households were randomly selected. From 2004 through 2007, research assistants administered an audio computer-assisted interview survey and collected biologic samples for gonorrhea and chlamydia testing. RESULTS: The final sample size included 575 participants from 63 CBGs. Additional data provided gonorrhea prevalence from 2004 through 2005 per 15- to 49-year-old persons per 100,000 per CBG. After adjustment for individual-level STI risk factors in a multilevel probability model, adolescents and young adults living in high (vs. low) prevalence STI areas were 4.73 times (95% confidence interval [CI]: 3.65-6.15) more likely to have a current incident STI. CONCLUSIONS: To inform prevention programs, future research should focus on identifying mechanisms through which context causes changes in local sexual networks and their STI prevalence.

Improving epidemiological surveys of sexual behaviour conducted by telephone.

BACKGROUND: This study assesses the impact of Telephone Audio Computer-Assisted Self-Interviewing (T-ACASI) on the reporting of sensitive (mainly heterosexual) behaviours. METHODS: A randomized experiment was embedded in a telephone survey that drew probability samples of the populations of the USA (N = 1543) and Baltimore city (N = 744). Respondents were randomly assigned to have questions asked either by a T-ACASI computer or by a human telephone interviewer. RESULTS: Compared with interviewer-administered telephone surveys, T-ACASI obtained more frequent reporting of a range of mainly heterosexual behaviours that were presumed to be sensitive, including recency of anal sex [adjusted odds ratio (A-OR) = 2.00, P < 0.001), sex during menstrual period (A-OR = 1.49, P < 0.001), giving oral sex (A-OR = 1.40, P = 0.001) and receiving oral sex (A-OR = 1.36, P = 0.002), and sexual difficulties for the respondent (A-OR = 1.45, P = 0.034) and their main sex partner (A-OR = 1.48, P = 0.0). T-ACASI also obtained less frequent reporting that respondent had a 'main sex partner' (A-OR = 0.56, P = 0.011) and discussed contraception prior to first sex with that sex partner (A-OR = 0.82, P = 0.094). For both males and females, T-ACASI obtained more frequent reports of first vaginal sex occurring at early ages (before ages 12 through 15). 'For males only', T-ACASI also elicited more frequent reports that first vaginal sex had 'not' occurred at later ages (i.e. by ages 20 through 24). CONCLUSION: T-ACASI increases the likelihood that survey respondents will report sensitive heterosexual behaviours.

Impact of T-ACASI on Survey Measurements of Subjective Phenomena.

Numerous studies have shown that audio-computer-assisted self-interviewing (audio-CASI) and telephone audio-CASI (T-ACASI) technologies yield increased reporting of sensitive and stigmatized objective phenomena such as sexual and drug use behaviors. Little attention has been given, however, to the impact of these technologies on the measurement of subjective phenomena (attitudes, opinions, feelings, etc.). This article reports results for the seven subjective measurements included in the National STD and Behavior Measurement Experiment (NSBME). NSBME drew probability samples of USA and Baltimore adults (Ns = 1,543 and 744, respectively) and randomized these respondents to be interviewed by T-ACASI or telephone interviewer-administered questioning (T-IAQ). Response distributions for all subjective measurements obtained by T-ACASI diverge from those obtained by human telephone interviewers. For six of our seven ordinal-scaled measurements, this divergence involved shifting responses directionally along the ordinal scale, as opposed to a nondirectional redistribution among response categories. When interviewed by T-ACASI, respondents were more supportive of traditional gender roles and corporal punishment, less supportive of integrated neighborhoods and same-gender sex, and more likely to agree that occasional marijuana use is harmless and to describe themselves as attractive. The majority of these results suggest that telephone survey respondents may provide more "tolerant" and "socially liberal" responses to human interviewers than to a T-ACASI computer. Similarly, although the evidence is not entirely consistent, the impact of T-ACASI appears to increase with the social vulnerability of the population surveyed.

Evaluation of risk score algorithms for detection of chlamydial and gonococcal infections in an emergency department setting.

OBJECTIVES: To develop and evaluate screening algorithms to predict current chlamydial and gonococcal infections in emergency department (ED) settings and assess their performance. METHODS: Between 2002 and 2005, adult patients aged 18 to 35 years attending an urban ED were screened for Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (GC) and completed a brief demographic and behavioral questionnaire. Using multiple unconditional logistic regressions, the authors developed four separate predictive models and applicable clinical risk scores to screen for infection. They developed models for females and males separately, for Ct and GC infections combined, and for Ct infection alone. The sensitivities and specificities of the clinical risk scores at different cutoffs were used to examine performance of the algorithms. RESULTS: Among 5,537 patients successfully screened for Ct and GC, the overall prevalence of infection was 9.6%. Age was the strongest predictor of infection. Adjusting for other predictors, the prevalence odds ratio (POR) was 2.2 (95% confidence interval [CI] = 1.7 to 2.8) for Ct and GC combined and 2.9 (95% CI = 2.1 to 4.1) for Ct alone comparing females 25 years and younger to females older than 25 years. Among males, the association was stronger with an adjusted POR of 3.3 (95% CI = 2.3 to 4.7) for Ct and GC combined and 3.2 (95% CI = 2.1 to 4.7) for Ct infection alone. CONCLUSIONS: If the decision to incorporate Ct and GC screening into routine ED care is made, age alone appears to be a sufficient screening criterion.

Health care access and follow-up of chlamydial and gonococcal infections identified in an emergency department.

BACKGROUND: We examined 2 potentially important factors influencing successful treatment of Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (GC) infections identified in an emergency department (ED), health care coverage and reporting the ED as a primary source for health care. METHODS: Adult patients aged 18 to 35 years attending an urban ED were screened for Ct and GC. Patients testing positive were contacted by Disease Intervention Specialists and notified of their infection status. Analyses focus on infected patients for whom we have treatment and follow-up information. We used generalized linear models with log link and binomial error distribution to estimate risk ratios (RRs) and 95% confidence intervals (CI). RESULTS: Of 5537 patients screened in the ED, 348 (6.3%) tested positive for Ct, 143 (2.6%) tested positive for GC, and 43 (0.8%) tested positive for both. Overall, 20% of infected patients did not receive treatment. Among infected patients with no health care coverage 25% (n = 56) were untreated compared with 15% (n = 47) of patients reporting health care coverage (RR: 1.7, 95% CI: 1.2-2.3). Among patients reporting the ED as a primary source for health care 26% (n = 27) were untreated compared with the 18% (n = 77) reporting receiving health care from non-ED sources (RR: 1.4, 95% CI: 1.0-2.1). CONCLUSIONS: EDs often serve as primary care sites for difficult-to-reach populations. We were able to successfully locate and treat the greater part of ED-identified infections. However, one-fifth of infected patients did not receive treatment. ED-based screening programs can benefit from integration with local public health infrastructure to improve notification and treatment services.

T-ACASI reduces bias in STD measurements: the National STD and Behavior Measurement Experiment.

BACKGROUND: Although telephone surveys provide an economical method for assessing patterns of diagnosed sexually transmitted diseases (STDs) and STD-related behaviors in populations, the requirement that respondents report such information to human telephone interviewers introduces an opportunity for substantial reporting bias. Telephone computer-assisted self-interviewing (T-ACASI) surveys substitute a computer for human interviewers when asking sensitive questions. METHODS: A randomized experiment was embedded in a telephone survey that drew probability samples of the populations of the United States (N = 1543) and Baltimore city (N = 744). Respondents were randomly assigned to have sensitive questions asked either by a T-ACASI computer or by a human telephone interviewer. RESULTS: Respondents interviewed by a T-ACASI computer were more likely to report STD symptoms [dysuria, genital sores, genital discharge, and genital warts; adjusted odds ratios (ORs) = 1.5-2.8] and a diagnosis of gonococcal or chlamydial infection during the past year (adjusted ORs = 3.6 and 6.1). T-ACASI respondents with a main sex partner in the past year were more likely to report that their partner has had an STD (adjusted OR = 2.4). For some measurements, the impact of T-ACASI was strongest among younger and less-educated respondents. When sampling weights were applied to project National STD and Behavior Measurement Experiment results to the populations of the United States and Baltimore, we found that reliance on data obtained by human interviewers would underestimate the annual incidence of chlamydial and gonococcal infections in these populations by factors of 2.4 to 9.7. CONCLUSIONS: Compared with human telephone interviewers, T-ACASI surveys obtain increased reporting of STD symptoms, infections, and STD-related behaviors.

SAME-GENDER SEX IN THE UNITED STATES IMPACT OF T-ACASI ON PREVALENCE ESTIMATES.

Well-conducted telephone surveys provide an economical means of estimating the prevalence of sexual and reproductive behaviors in a population. There is, however, a nontrivial potential for bias since respondents must report sensitive information to a human interviewer. The National STD and Behavior Measurement Experiment (NSBME) evaluates a new survey technology-telephone audio computer-assisted self-interviewing (T-ACASI)-that eliminates this requirement. The NSBME embedded a randomized experiment in a survey of probability samples of 1,543 U.S. and 744 Baltimore adults ages 18 to 45. Compared with NSBME respondents interviewed by human interviewers, respondents interviewed by T-ACASI were 1.5 to 1.6 times more likely to report same-gender sexual attraction, experience, and genital contact. The impact of T-ACASI was more pronounced (odds ratio = 2.5) for residents of locales that have historically been less tolerant of same-gender sexual behaviors and for respondents in households with children (odds ratio = 3.0).

SAME-GENDER SEX AMONG U.S. ADULTS: TRENDS ACROSS THE TWENTIETH CENTURY AND DURING THE 1990s.

Trends in reporting of same-gender sex are assessed using data from the 1988-2002 General Social Surveys (Ns = 9,487 males and 12,336 females). Analyses indicate that the reported prevalence of female-female sexual contact increased substantially and monotonically across twentieth-century birth cohorts, rising from 1.6 percent (Standard error [SE] = 0.60) for the cohort of U.S. women born prior to 1920 to 6.9 percent (SE = 0.81) for women born in 1970 and afterward. Increases in the reported prevalence of female-female contacts also occurred within the 1990s. These trends persist when statistical controls are introduced for changes in attitudes toward same-gender sexual behavior. No parallel trend is observed in the reporting of male-male sexual contacts during adulthood, although the proportion of U.S. men reporting such contacts in the past year and in the past five years increased during the 1990s.

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.

Measuring AIDS-Related Behaviors in Older Populations: Methodological Issues.

Because of a dearth of research on reporting biases in the measurement of HIV-related sexual and drug use behaviors in older populations, it is frequently assumed that methodological findings of research conducted with younger populations will generalize to older respondents. In this study, estimates of the effect of the experimental manipulation of interview mode (interviewer administered vs. self-administered) were derived separately for three age strata: 12 to 49, 50 to 64, and 65+. Results of these analyses indicate that there were a number of noteworthy reversals in which interviewer-administered questioning in the older age strata produced higher esti-mates of the prevalence of substance use or alcohol-related problem behaviors. These results suggest that caution should be exercised in making generalizations from studies of reporting bias for HIV-related behaviors to older populations.

Interview Mode and Measurement of Sexual Behaviors: Methodological Issues.

Studies of sexual and other sensitive behaviors are often fraught with a variety of reporting biases. When IAQs are used to collect data, respondents may underreport certain sensitive behaviors and overreport normative behaviors. SAQs can also pose problems: requiring that respondents be literate and able to follow skip patterns. In recent years, the development of computerized technologies--audio-CASI and T-ACASI--have begun to overcome some of the limitations of IAQs and SAQs. By providing a more private mode for data collection and standardized delivery of all questions, as well as automated skip patterns and range checks, audio-CASI and T-ACASI have been tested in a number of studies and found to be an effective way of reducing response bias, and thus, contributing to a better understanding of the prevalence and patterns of sexual and other sensitive behaviors.