Geoffrey T. Fong

The authors propose that experiments that utilize mediational analyses as suggested by R. M. Baron and D. A. Kenny (1986) are overused and sometimes improperly held up as necessary for a good social psychological paper. The authors argue that when it is easy to manipulate and measure a proposed psychological process that a series of experiments that demonstrates the proposed causal chain is superior. They further argue that when it is easy to manipulate a proposed psychological process but difficult to measure it that designs that examine underlying process by utilizing moderation can be effective. It is only when measurement of a proposed psychological process is easy and manipulation of it is difficult that designs that rely on mediational analyses should be preferred, and even in these situations careful consideration should be given to the limiting factors of such designs.

BACKGROUND: This paper describes the methods and conceptual framework for Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study data collection. The National Institutes of Health, through the National Institute on Drug Abuse, is partnering with the Food and Drug Administration's (FDA) Center for Tobacco Products to conduct the PATH Study under a contract with Westat. METHODS: The PATH Study is a nationally representative, longitudinal cohort study of 45 971 adults and youth in the USA, aged 12 years and older. Wave 1 was conducted from 12 September 2013 to 15 December 2014 using Audio Computer-Assisted Self-Interviewing to collect information on tobacco-use patterns, risk perceptions and attitudes towards current and newly emerging tobacco products, tobacco initiation, cessation, relapse behaviours and health outcomes. The PATH Study's design allows for the longitudinal assessment of patterns of use of a spectrum of tobacco products, including initiation, cessation, relapse and transitions between products, as well as factors associated with use patterns. Additionally, the PATH Study collects biospecimens from consenting adults aged 18 years and older and measures biomarkers of exposure and potential harm related to tobacco use. CONCLUSIONS: The cumulative, population-based data generated over time by the PATH Study will contribute to the evidence base to inform FDA's regulatory mission under the Family Smoking Prevention and Tobacco Control Act and efforts to reduce the Nation's burden of tobacco-related death and disease.

CONTEXT: African American adolescents are at high risk of contracting sexually transmitted infection with human immunodeficiency virus (HIV), but which behavioral interventions to reduce risk are most effective and who should conduct them is not known. OBJECTIVE: To evaluate the effects of abstinence and safer-sex HIV risk-reduction interventions on young inner-city African American adolescents' HIV sexual risk behaviors when implemented by adult facilitators as compared with peer cofacilitators. DESIGN: Randomized controlled trial with 3-, 6-, and 12-month follow-up. SETTING: Three middle schools serving low-income African American communities in Philadelphia, Pa. PARTICIPANTS: A total of 659 African American adolescents recruited for a Saturday program. INTERVENTIONS: Based on cognitive-behavioral theories and elicitation research, interventions involved 8 1-hour modules implemented by adult facilitators or peer cofacilitators. Abstinence intervention stressed delaying sexual intercourse or reducing its frequency; safer-sex intervention stressed condom use; control intervention concerned health issues unrelated to sexual behavior. MAIN OUTCOME MEASURES: Self-reported sexual intercourse, condom use, and unprotected sexual intercourse. RESULTS: Mean age of the enrollees was 11.8 years; 53% were female and 92.6% were still enrolled at 12 months. Abstinence intervention participants were less likely to report having sexual intercourse in the 3 months after intervention than were control group participants (12.5% vs 21.5%, P=.02), but not at 6- or 12-month follow-up (17.2% vs 22.7%, P=.14; 20.0% vs 23.1%, P=.42, respectively). Safer-sex intervention participants reported significantly more consistent condom use than did control group participants at 3 months (odds ratio [OR]=3.38; 95% confidence interval [CI], 1.25-9.16) and higher frequency of condom use at all follow-ups. Among adolescents who reported sexual experience at baseline, the safer-sex intervention group reported less sexual intercourse in the previous 3 months at 6- and 12-month follow-up than did control and abstinence intervention (adjusted mean days over prior 3 months, 1.34 vs 3.77 and 3.03, respectively; P< or =.01 at 12- month follow-up) and less unprotected intercourse at all follow-ups than did control group (adjusted mean days, 0.04 vs 1.85, respectively, P<.001, at 12-month follow-up). There were no differences in intervention effects with adult facilitators as compared with peer cofacilitators. CONCLUSION: Both abstinence and safer-sex interventions can reduce HIV sexual risk behaviors, but safer-sex interventions may be especially effective with sexually experienced adolescents and may have longer-lasting effects.