Database

Epidemiology provides data and tools with which to measure case load and to estimate liability exposure. Key concept = attributable risk; the basis of reliable probabilistic estimates of exposure. Evidence from: Andrew@reliabilityoxford.co.uk Attributable Risk If an exposure to a risk leads to an increased rate of ill health outcome, the absolute effect of exposure is measured by the difference between rate of occurrence in the exposed group (RE) and the rate occurrence in the unexposed group (RU). The difference in these rates, measures the rate attributable to exposure to the risk. Attributable risk rate = RE – RU Following from this; Attributable Fraction = (RE – RU )/ RU Which is the same as; Attributable Fraction = (RR-1)/RR where RR = relative risk, the result obtained from most epidemiological studies). For example, a RR of 2 gives an attributable fraction of 50%. For example, a RR of 3 gives an attributable fraction of 66%. It is quite possible for an individual to

Two studies of atopy (the innate risk of developing an allergy) and the effect of exposure to allergens. Given that people with a history of allergies are more likely to develop occupational allergy perhaps this should be used as a pre-placement screening enquiry?  Evidence from: BM Sympson et al. Clinical and Experimental Allergy. March (2001) Vol. 31 # 3 p 391. DH Garabrant et al. American Journal of Epidemiology. March (2001) Vol. 153 #6 p 515.   The Radar report is available to subscribers: 1#4 12

The study compared lung cancer risk in an occupational cohort with the relevant normal population in the USA. Workers were exposed to silica in sand dust. The potential effects of radon exposure were reduced to a minimum. Evidence from: K.Steenland et al. American Journal of Epidemiology. April (2001). Vol. 153 #7 p 695. The report provides exposure estimates and the strength of association between exposure and lung cancer. Dose response trends were looked for. Given the number of people exposed to silica dust at higher than the recommended level it would be possible to estimate the attributable case load. The Radar report is available to subscribers: 1#4 11

This was a study of multiple chemical sensitivity (MCS) and chronic fatigue syndrome (CFS) in war veterans (Gulf1, Bosnia). Evidence from: S.Reid et al. (Simon Wessely) American Journal of Epidemiology. March (2001) Vol. 153 #6 p604. The Radar report is available to subscribers: 1#4 10

The paper reports an estimate of the normal incidence of hypospadias (a male genital malformation observed at birth). Evidence from: HEVirtanen et al. APMIS Feb. (2001) Vol. 109, #2 p 96. Changes in incidence would alert researchers to look for an environmental cause.. In Finland, there has been no change of incidence between 1970 and 1999. This paper provides a useful baseline against which to assess any change. The Radar report is available to subscribers: 1#4 9

Pain hypersensitivity could explain disability where tissue damage is absent. This preliminary study provides tentative clues about this phenomenon and its potential prognostic power. MWerneke et al. Spine. April (2001) Vol. 26 #7 p 758 A proposed new method for predicting chronicity of low back pain following an acute attack. The authors propose that centralisation of pain within weeks of the acute attack may indicate a better outcome. Centralisation phenomenon is where the pain migrates from the distal or peripheral to the proximal or central. The authors conclude that the negative assessment of centralisation in the first few weeks is a useful predictor of continuing (long-term) pain and disability. However, the study was either not well designed or poorly reported. Comment A semi objective test would be very useful in selecting back pain cases that ought to be managed more closely. The method proposed here is not validated by this study, but it is likely (given the desire to find a