The majority of renal cell carcinomas (RCCs) are sporadic, and increasing incidence rates suggest that such environmental risk factors as smoking play a role in the etiology of the disease. Cases with RCC were selected from the population-based cancer registry of Orange County, California, between 1994 and 1997; controls were recruited by telephone using random digit dialing. A total of 115 case and 259 control subjects were genotyped for N-acetyltransferase 2 (NAT2), which codes for a polymorphic enzyme involved in tobacco-carcinogen metabolism. Subjects with slow acetylator genotypes were found to be at twofold increased risk (odds ratio (OR) = 1.8; 95 percent confidence interval (CI): 1.1, 2.9) of RCC. Although cancer risk doubled among smokers (OR = 2.2; 95 percent CI: 1.3, 3.7), stratified analysis revealed gene-environment interaction among slow acetylators that smoked (OR = 3.2; 95 percent CI: 1.7, 6.1) compared with rapid acetylators that smoked (OR = 1.4; 95 percent CI: 0.7, 2.9). A dose response was found for pack-years among slow acetylators (p < 0.01) but not among rapid acetylators (p = 0.06). Although smoking is a well-established risk factor of RCC, our data suggest that the risk is pronounced among slow rather than rapid acetylators.

Objectives

Associations of emergency department (ED) visits and hospital admissions for asthma in children with demographics and area socio-economic status (SES) were examined to evaluate long-term trends and identify vulnerable populations.

Study design

Retrospective population-based trend and cross-sectional analyses.

Methods

Asthma hospital admissions (2000-2007) and ED visits (2005-2007) for children aged 0-14 years living in Orange County, California were linked with zip-code-level SES data (2000 US Census). Annual population estimates were obtained to calculate age-specific admissions and ED visit rates. Average annual percentage changes (AAPC) were calculated with joinpoint analyses. The risks of ED visits and hospital admissions were estimated from SES indicators with negative binomial regression.

Results

Rates of asthma hospital admissions and ED visits were highest among children aged 0-4 years, males and African Americans, and lowest among Asian/Pacific Islanders. African Americans and Hispanics/Latinos were more likely to be uninsured. Asthma admissions decreased significantly for all age groups over the study period. The greatest declines per 100,000 were among children aged 0-4 years (AAPC: -15.3%, 95% confidence interval -17.0% to -13.4%). Rates of hospital admissions and ED visits were significantly higher in low-SES groups. Hospital admission rates were 30-60% higher and ED visits were 80-90% higher in zip codes in the lowest tertile of median household income compared with the highest tertile of median household income.

Conclusions

Paediatric asthma hospitalizations and ED visit rates are declining in Orange County. However, certain groups are disproportionately affected, including those living in areas with low SES. This information will help in targeting intervention strategies to children at highest risk for severe asthma episodes.

Objective

The aim of this study was to describe recruitment strategies for a single-visit cervical cancer prevention study.

Methods

From January through December 1999, low-income, predominantly Latino women were recruited to participate in a single-visit cervical cancer prevention study. For the first 6 months, all women who had ever visited one of two community-based study clinics were invited to participate (clinic registry recruitment). For the remainder of the year, recruitment was modified to be primarily inclusive of advertisements in English- and Spanish-language community newspapers and fliers left in local businesses and organizations (media campaign recruitment). Eligible volunteers were randomized to one of two study arms, usual-care program or single-visit program. All study subjects completed demographic and medical questionnaires delivered by bilingual staff. Women who declined to participate in this study were asked to provide reasons for this preference. Statistical analyses included the use of chi-square, logistic regression, and Student's t test.

Results

The proportion of women who agreed to participate was higher in the media recruitment group than in the clinic registry group [51% (535/1041) compared to 26% (405/1542), P < 0.001]. The no-show rate among participants solicited from the media strategy was significantly less than that from the clinic registry. There were no significant differences in the median age, number of months since the last Papanicolaou smear, incidence of abnormal Papanicolaou smear, education, or income of the subjects based on the recruitment strategy.

Conclusion

A media-based recruitment strategy was effective for this single-visit cervical prevention study. This approach may be effective for recruitment of other low-income groups to clinical trials.