BACKGROUND To explore why increased access to emergency contraception (EC) failed to reduce pregnancies in a recent randomized controlled trial. METHODS We used multivariable logistic regression to identify risk factors for unintended pregnancy using data from a trial involving sexually active women (n = 1490, aged 14-24 years) randomly assigned to either increased access or standard access t...

OBJECTIVES The objective of this article was to explore overall crash and injury trends over the past decade for young drivers residing in New South Wales (NSW), Australia, including gender and age disparities. METHODS Passenger vehicle crashes for drivers aged 17-25 occurring during 1997-2007 were extracted from the state crash database to calculate crash rates (per licensed driver). General...

This paper proposes a new method of improved meta analysis to combine relative risk for both homogeneous and heterogeneous set of studies. The standard meta analyses don’t give any conclusive result when the effects of heterogenous studies are combined. The proposed improved meta analysis uses the predicted relative risk, and chi-square test to check the heterogeneity of the effects. Confidence...

SUMMARY Interval-censored life-history data arise when the events of interest are only detectable at periodic assessments. When interest lies in the occurrence of two such events, bivariate-interval censored event time data are obtained. We describe how to fit a four-state Markov model useful for characterizing the association between two interval-censored event times when the assessment times ...

TO THE EDITOR—Kiraly and coauthors recently commented [1] that confounding by age might explain the apparent reduced risk of pertussis described by Witt et al [2] among persons vaccinated with a whole-cell pertussis vaccine (wP) compared to recipients of acellular pertussis vaccine (aP). We note that Table 3 of the original article [2] provides sufficient data to estimate the pertussis attack r...

Association-based linkage disequilibrium (LD) mapping is an increasingly important tool for localizing genes that show potential influence on human aging and longevity. As haplotypes contain more LD information than single markers, a haplotype-based LD approach can have increased power in detecting associations as well as increased robustness in statistical testing. In this paper, we develop a ...

OBJECTIVE To assess the absolute and relative risks of youth school-related travel using the New Zealand's no fault accident liability scheme and Census at School datasets. METHODS Injury risk associated with traveling to and from school was assessed by combining census data from the Accident Compensation Commission database, New Zealand's no fault liability accident scheme database and the C...

BACKGROUND Offering free glasses can be important to increase children's wear. We sought to assess whether "Upgrade glasses" could avoid reduced glasses sales when offering free glasses to children in China. METHODS In this cluster-randomized, controlled trial, children with uncorrected visual acuity (VA)< = 6/12 in either eye correctable to >6/12 in both eyes at 138 randomly-selected primary...

Schistosomiasis control in China is facing a new challenge due to the rebound of epidemics in many areas and the unsustainable effects of the chemotherapy-based control strategy. Identifying high-risk regions for schistosomiasis is an important first step for an effective and sustainable strategy. Direct surveillance of snail habitats to detect high-risk regions is costly and no longer a desira...

The incidences of alimentary and respiratory illnesses were observed during the first year of life in 1565 infants born in Tayside during 1980. Significant correlations (p less than 0.05) were found between each of these outcomes and parental smoking, maternal age, social class, method of infant feeding, and heating fuels. Multiple logistic regression indicated a significant independent effect ...