Impact of detection bias on the risk of gastrointestinal cancer and its subsites in type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) may be a risk factor for gastrointestinal (GI) cancers, but variations in study designs of observational studies may have yielded biased results due to detection bias. Furthermore, differences in risk for GI cancer subsites have not been extensively evaluated. We aimed to determine the risk of GI cancer and its subsites in patients with T2DM and how it is affected by detection bias. METHODS: A matched cohort study was performed using the NCR-PHARMO database. New-users of ≥1 non-insulin anti-diabetic drug during 1998-2011 were matched with non-diabetic controls by year of birth, sex, and time between database entry and index. Cox regression analyses were performed with and without lag-period to estimate hazard ratios (HRs) for GI cancer and its subsites. Covariables included age, sex, use of other drugs and history of hospitalisation. RESULTS: An increased risk of GI cancer was observed in T2DM patients (HR 1.5, 95% confidence interval [CI] 1.3-1.7) compared with controls, which was attenuated in the 1-year lagged analysis (HR 1.4, 95% CI 1.2-1.7). Stratified by subsite, statistically significant increased risks of pancreatic (HR 4.7, 95% CI 3.1-7.2), extrahepatic bile duct (HR 4.2, 95% CI 1.5-11.8) and distal colon cancer (HR 1.5, 95% CI 1.1-2.1) were found, which remained statistically significantly increased in the lagged analysis. CONCLUSIONS: T2DM patients had a 40% increased risk of GI cancer. Increased GI cancer risks tended to be weaker when reducing detection bias by applying a 1-year lag-period. Future observational studies should therefore include sensitivity analyses in which this bias is minimised.

Community reaction to aircraft noise: time-of-day penalty and tradeoff between levels of overflights.

A decrease in the level of sound events can compensate for an increase in the level of other events, but noise metrics assume different tradeoffs. Noise metrics also differ in the penalty applied to noise in the evening and to noise in the night, and in the definition of these periods. These two aspects of noise metrics, i.e., the tradeoff and the penalty for the nighttime (23-7h), are investigated. A general model of the relation between SELs of sound events (aircraft overflights) and noise annoyance is presented which allows for a wide range of tradeoffs and time-of-day penalties. The (tradeoff and time-of-day penalty) parameters of the model are fitted to the data from an aircraft noise study conducted around Amsterdam Airport Schiphol, which is especially suited for investigating the tradeoff and time-of-day penalties. It was found that in this study the tradeoff between the levels of events in metrics based on L(Aeq)'s, such as L(Aeq)(24 h), DNL, and DENL, is approximately correct for the prediction of noise annoyance. Furthermore, it was found that the strongest correlation with annoyance is obtained with a nighttime penalty of circa 10 dB. No suitable data were available for further tests of the tradeoff. The result with respect to the nighttime penalty was weakly further supported by the outcome of analyses of the original data from four other aircraft noise surveys (one survey conducted around British airports, and three coordinated surveys carried out around Paris Orly, Amsterdam Schiphol, and Glasgow Abbotsinch).

Review: extraaural health effects of aircraft noise.

The number of aircraft movements in our society is increasing at a rapid rate. As a consequence the airspace is becoming more crowded, in particular in the vicinity of airports. As a consequence pollution (both air pollution and noise) near the airports increases. One solution to 'rush hours' in the airspace around airports is to spread the number of flights more evenly over time. This leads to more flights in the sensitive parts of the day: evening and night. This leads to community reaction and places the potential health effects of noise in the focus of societal attention. Human functioning is affected by noise in many ways. Effects of noise become detectable at a relatively low noise level, approx. 30 dB(A). Above which noise levels and under what conditions these effects become threatening to health is still largely unknown. This holds true for cardiovascular effects, mental health, mortality rates, medicine consumption, pregnancy, delivery and physical development. On some aspects more certainty exists. Night time noise when it causes people to wake up or prevents them from falling asleep, or when it frequently disturbs the structure of sleep below the waking level, can be detrimental to health. Both for awakening reactions and for annoyance, exposure-response relations are rather well established. Reading ability is hampered by noise. For the vegetative aspects, no clear and stable exposure-response relations are known at this moment. Hopefully this conference will fill in the gap.