Biomedical subjects

Jan-Eric Litton

Publications and source records attributed to Jan-Eric Litton.

4 recordsLinked to original sources

PubMed2007

Optimizing the design of web-based questionnaires--experience from a population-based study among 50,000 women.

BACKGROUND: Web-questionnaires are an important tool for future epidemiological research because these allow for rapid and cost-efficient assembly of self-reported information on risk factors and health outcomes. However, to achieve high response rates it is essential to accommodate factors that prevent drop out and so insure validity of future studies. We aim to study how socio-demographic variables as well as design issues such as the ordering and level of difficulty (Easy-to-hard vs. Hard-to-easy) of questions in a web-questionnaire affects the probability of drop out and non-response. METHOD: In 2003 we invited 47,859 women participating in an ongoing prospective study to a follow-up using a web-based mode. Two versions of the questionnaire existed, varying in level of difficulty (Easy-to-hard vs. Hard-to-easy). We report drop out (proportion non-completers) between groups defined by level of difficulty and estimated adjusted risk differences. RESULTS: The drop out differs significantly depending on the order of the questions in the web-questionnaire. The socio-demographic pattern among lurkers (participants that enter, start responding to, but do not complete a web-questionnaire) differs from that among completers of web-questionnaires. CONCLUSIONS: An additional 6% units of completers--persons initiating and completing the questionnaire--can be obtained by considering the ordering of questions. A group uniquely identified in web-surveys, as lurkers are potentially easier to persuade to complete an already started web-questionnaire compared to a non-responder. Lurkers thus constitute a unique opportunity of decreasing the drop out rate and therefore merit future research.

Cohort Studies↗

PubMed2006

Feasibility of using web-based questionnaires in large population-based epidemiological studies.

To date, few large web-based epidemiological studies have been performed in a population-based setting. Sweden has optimal prerequisites for web-based studies with more than 80% of the general population having access to the Internet. Our aim was to investigate (I) response rates in an epidemiological study using primarily the web as a tool for data collection and (II) whether socio-demographic patterns vary between responders to a web and a paper questionnaire. In 2003, we invited 47,859 women to complete a web questionnaire. Two reminders were sent to non-responders; in the first a random sample received a paper questionnaire and in the second the majority received a paper questionnaire. All other non-responders received web questionnaires. Differences in response rates between responders to web and paper questionnaires with regard to socio-demographic and other variables were analyzed, and estimates of the bias introduced by these differences were estimated. In total, 41% of the women responded to the web questionnaire and 31% to the paper questionnaire (overall response rate 72%). The web-, paper- and non-responders respectively did not differ significantly in age, physical activity levels, and body mass index. Women answering web or paper questionnaires had a higher level of education and income and a lower level of smoking than non-responders. The bias associated with collecting information using web questionnaires was not greater than that caused by paper questionnaires. We conclude that web-based questionnaires are a feasible tool for data collection in large population based epidemiological studies in Sweden.

Adult↗

PubMed2005

Can we trust cancer information on the Internet?--A comparison of interactive cancer risk sites.

OBJECTIVE: To investigate the prevalence and quality of interactive cancer risk sites on the Internet. METHODS: A cancer risk site was defined as a website that gave an estimate of the individual risk of developing cancer. Six search engines and one Meta crawler were used to search the Internet for cancer risk sites (including breast, prostate, colon, and lung cancer). A set of defined quality criteria for health related websites was used to evaluate the websites during 2001 and 2002. RESULTS: The number of cancer risk sites, as defined above, increased by 50% between 2001 and 2002. Only two out of 22 cancer risk sites fulfilled the quality criteria adequately. No signs of a change in trend (with regard to the quality criteria met) were noted in January 2005. CONCLUSIONS: The overall quality of the documentation on the cancer risk sites was poor and no improvement was seen during the study period. The majority of the cancer risk sites do not give reliable risk estimates.

Humans↗

PubMed2003

Data modeling and data communication in GenomEUtwin.

Database infrastructure has become a critical component for competitive life sciences research and discovery. The explosion of data requires that the data are properly loaded, accessed, managed, queried, analyzed, and shared with others. The key purpose of the population-based twin cohorts housed at different institutions in Europe is to gather an extremely large quantity of information from their twin populations, and share it. Longitudinal research over a long period of time, hopefully generations, demands completely new methods and systems to handle the gathering of information and storing. These cohorts bring to the fore problems concerning the need for a standardization of research data and a computer and storage strategy. In the following we describe the preliminary strategy being implemented in the Database Core of GenomEUtwin.

Database Management Systems↗