Latent Class Analysis Identifies Distinctive Behavioral Subtypes in Children with Fragile X Syndrome.

Fragile X syndrome (FXS) is characterized by variable neurobehavioral abnormalities, which leads to difficulties in developing and evaluating treatments and in determining accurate prognosis. We employed a pediatric cross-sectional sample (1,072 males, 338 females) from FORWARD, a clinic-based natural history study, to identify behavioral subtypes by latent class analysis. Input included co-occurring behavioral conditions, sleep and sensory problems, autistic behavior scales (SCQ, SRS-2), and the Aberrant Behavior Checklist revised for FXS (ABCFX). A 5-class solution yielded the most clinically meaningful, pharmacotherapy independent behavioral groups with distinctive SCQ, SRS-2, and ABCFX profiles, and adequate non-overlap (≥ 71%): "Mild" (31%), "Moderate without Social Impairment" (32%), "Moderate with Social Impairment" (7%), "Moderate with Disruptive Behavior" (20%), and "Severe" (9%). Our findings support FXS subtyping, for improving clinical management and therapeutic development.

Do tobacco countermarketing campaigns increase adolescent under-reporting of smoking?

This study assesses whether a national anti-tobacco campaign for youth could create a social context that would elevate social desirability response bias on surveys, as measured by an increase in under-reporting of smoking. This could give rise to data that falsely suggest a campaign-induced decline in youth smoking, or it could exaggerate campaign effects. Data were obtained from a national sample of 5511 students from 48 high schools that were matched to schools sampled for the 2002 National Youth Tobacco Survey (NYTS). Self-reported smoking was compared with biochemical indicators of smoking, measured using saliva cotinine. The rate of under-reporting detected was 1.3%. Level of truth exposure was not related to under-reporting. This study suggests that for high school students, anti-tobacco campaigns are not an important cause of social desirability responses on surveys, and that in general under-reporting smoking is not a major source of error in school-based surveys.

Reactions of young adult smokers to warning labels on cigarette packages.

BACKGROUND: In 1984, the United States Congress enacted legislation requiring four new warning labels for cigarettes; warning labels in the United States have not changed since then. Other countries, such as Canada, have taken a more active and aggressive approach. The purpose of this study was to examine how U.S. smokers and former smokers might respond to stronger and more graphic warnings for U.S. cigarettes packages. METHODS: Data were collected in 2003 and analyzed in 2004. The perceived impact and effectiveness of the more-explicit Canadian labels was examined among young adult smokers (n=572) and former smokers (n=191) between the ages of 18 and 24 years in the United States, using a web-based survey that allowed participants to view both the text-only and the text-plus-graphic warning labels. RESULTS: Both current and former smokers thought that cigarette warning labels with text plus graphics were substantially more of a deterrent than text-only labels. The perceived effectiveness of these labels was not only higher overall, but also for the specific areas of smoking-related health effects, prevention, cessation, and maintenance of abstinence. Few differences were noted by gender. CONCLUSIONS: The findings from this study support previous research that has found that text-plus-graphic warning labels are more salient and potentially more effective than text-only labels.

Progression to established smoking among US youths.

OBJECTIVES: Our study presents national estimates of the proportion of youths in each of 7 stages of smoking and investigates the associations between risk/protective factors and progression to established smoking. METHODS: We analyzed data from the 1999 and 2000 National Youth Tobacco Surveys. RESULTS: In 1999 and 2000, 48.6% of US adolescents had at least experimented with tobacco, and 7.8% were established smokers. Important correlates of progression to established smoking included parental advice not to smoke, antismoking lessons in school, susceptibility to tobacco industry advertising and promotion, peer smoking, and exposure to smoking at home. CONCLUSIONS: Interventions to stop adolescent progression to established smoking should target susceptible never smokers and early experimenters as well as those in later stages of smoking.