Internet Surveys by Direct Mailing: An Innovative Way of Collecting Data

This article describes a new method of collecting data by direct mailing via the Internet. Feasibility and capacities were evaluated through a worldwide opinion poll on global future risks of mankind and potential solutions. Within 1 day, a structured questionnaire was sent to 8,859 randomly selected e-mail addresses. One thousand seven hundred and thirteen were remailed properly completed, 90 within 4 days. Most respondents were residents of North America (64) and Europe (21 ), male (87), and 30 years old on average. Environmental destruction (52) was mentioned as the primary problem, followed by violence (45) and unemployment (45). Education (71 ) was the most frequently proposed solution to future problems. It is obvious that Internet surveys at this time are not repre sentative of the total population. However, they open new dimensions in the interrogation of experts and opinion leaders, especially considering their efficiency and potential for automation

quantifying the risk reduction potential of new modified risk tobacco products

Abstract Quantitative risk assessment of novel Modified Risk Tobacco Products (MRTP) must rest on indirect measurements that are indicative of disease development prior to epidemiological data becoming available. For this purpose, a Population Health Impact Model (PHIM) has been developed to estimate the reduction in the number of deaths from smoking-related diseases following the introduction of an MRTP. One key parameter of the model, the F-factor, describes the effective dose upon switching from cigarette smoking to using an MRTP. Biomarker data, collected in clinical studies, can be analyzed to estimate the effects of switching to an MRTP as compared to quitting smoking. Based on transparent assumptions, a link function is formulated that translates these effects into the F-factor. The concepts of 'lack of sufficiency' and 'necessity' are introduced, allowing for a parametrization of a family of link functions. These can be uniformly sampled, thus providing different 'scenarios' on how biomarker-based evidence can be translated into the F-factor to inform the PHIM

Development and validation of a new instrument to measure perceived risks associated with the use of tobacco and nicotine-containing products

Making tobacco products associated with lower risks available to smokers who would otherwise continue smoking is recognized as an important strategy towards addressing smoking-related harm. Predicting use behavior is an important major component of product risk assessment. In this context, risk perception is a possible factor driving tobacco product uptake and use. As prior to market launch real-world actual product use cannot be observed, assessing risk perception can provide predictive information. Considering the lack of suitable validated self-report instruments, the development of a new instrument was undertaken to quantify perceived risks of tobacco and nicotine-containing products by adult smokers, former smokers and never-smokers. Initial items were constructed based on a literature review, focus groups and expert opinion. Data for scale formation and assessment were obtained through two successive US-based web surveys (n=2020 and 1640 completers, respectively). Psychometric evaluation was based on Rasch Measurement Theory and Classical Test Theory. Psychometric evaluation supported the formation of an 18-item Perceived Health Risk scale and a 7-item Perceived Addiction Risk scale: item response option thresholds were ordered correctly for all items; item locations in each scale were spread out (coverage range 75-87%); scale reliability was supported by high person separation indices > 0.93, Cronbach's alpha > 0.98 and Corrected Item-Total Correlations > 0.88; and no differential item functioning was present. Construct validity evaluations met expectations through inter-scale correlations and findings from known-group comparisons. The Perceived Risk Instrument is a psychometrically robust instrument applicable for general and personal risk perception measurement, for use in different types of products (including cigarettes, nicotine replacement therapy, potential Modified Risk Tobacco Products), and for different status groups (i.e., current smokers with and without intention to quit, former smokers, never smokers)

Effectiveness of strategies to increase the validity of findings from association studies: size vs. replication

<p>Abstract</p> <p>Background</p> <p>The capacity of multiple comparisons to produce false positive findings in genetic association studies is abundantly clear. To address this issue, the concept of false positive report probability (FPRP) measures "the probability of no true association between a genetic variant and disease given a statistically significant finding". This concept involves the notion of prior probability of an association between a genetic variant and a disease, making it difficult to achieve acceptable levels for the FPRP when the prior probability is low. Increasing the sample size is of limited efficiency to improve the situation.</p> <p>Methods</p> <p>To further clarify this problem, the concept of true report probability (TRP) is introduced by analogy to the positive predictive value (PPV) of diagnostic testing. The approach is extended to consider the effects of replication studies. The formula for the TRP after k replication studies is mathematically derived and shown to be only dependent on prior probability, alpha, power, and number of replication studies.</p> <p>Results</p> <p>Case-control association studies are used to illustrate the TRP concept for replication strategies. Based on power considerations, a relationship is derived between TRP after k replication studies and sample size of each individual study. That relationship enables study designers optimization of study plans. Further, it is demonstrated that replication is efficient in increasing the TRP even in the case of low prior probability of an association and without requiring very large sample sizes for each individual study.</p> <p>Conclusions</p> <p>True report probability is a comprehensive and straightforward concept for assessing the validity of positive statistical testing results in association studies. By its extension to replication strategies it can be demonstrated in a transparent manner that replication is highly effective in distinguishing spurious from true associations. Based on the generalized TRP method for replication designs, optimal research strategy and sample size planning become possible.</p

Meta-analysis of the relation between European and American smokeless tobacco and oral cancer

<p>Abstract</p> <p>Background</p> <p>Smokeless tobacco is often referred to as a major contributor to oral cancer. In some regions, especially Southeast Asia, the risk is difficult to quantify due to the variety of products, compositions (including non-tobacco ingredients) and usage practices involved. In Western populations, the evidence of an increased risk in smokeless tobacco users seems unclear, previous reviews having reached somewhat differing conclusions. We report a detailed quantitative review of the evidence in American and European smokeless tobacco users, and compare our findings with previous reviews and meta-analyses.</p> <p>Methods</p> <p>Following literature review a meta-analysis was conducted of 32 epidemiological studies published between 1920 and 2005 including tests for homogeneity and publication bias.</p> <p>Results</p> <p>Based on 38 heterogeneous study-specific estimates of the odds ratio or relative risk for smokeless tobacco use, the random-effects estimate was 1.87 (95% confidence interval 1.40–2.48). The increase was mainly evident in studies conducted before 1980. No increase was seen in studies in Scandinavia. Restricting attention to the seven estimates adjusted for smoking and alcohol eliminated both heterogeneity and excess risk (1.02; 0.82–1.28). Estimates also varied by sex (higher in females) and by study design (higher in case-control studies with hospital controls) but more clearly in studies where estimates were unadjusted, even for age. The pattern of estimates suggests some publication bias. Based on limited data specific to never smokers, the random-effects estimate was 1.94 (0.88–4.28), the eight individual estimates being heterogeneous and based on few exposed cases.</p> <p>Conclusion</p> <p>Smokeless tobacco, as used in America or Europe, carries at most a minor increased risk of oral cancer. However, elevated risks in specific populations or from specific products cannot definitely be excluded.</p

Perception and prevalence of behavioral risk factors : the lifestyle risk scale (LRS)

Objective: To develop a lifestyle risk scale (LRS) of health-related behaviors based on risk assessments of study participants. Method: By means of pairwise comparisons of assessed risks associated with tobacco, alcohol, obesity, fast-food, physical inactivity, and lack of sleep, each at four levels, 24 behaviors were ranked on a unidimensional risk scale. Results: Overall, use of tobacco was assigned the highest risk score (3.7), consumption of fast-food and lack of sleep the lowest (1.7, 1.6). Minor risk factors (lack of sleep and fast-food) were, at their highest levels, assigned similar risk values as major risk factors (tobacco, alcohol, obesity) at their lowest levels. Lifestyles of female participants were less hazardous than those of male participants, as measured with the LRS. In contrast, perception of behavioral health risks was more precise in men. Conclusions: The LRS provides a practical quantification to identify and compare groups with different risk behavior patterns as well as clusters of risky health be- haviors in and across populations. It can also support the communication of behavioral health risks