Epidemiological principles for EMF and EMR studies - Lincoln ...

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11 two-tailed test is appropriate. The usual 95%CI method used in the 2x2 calculation almost universally uses a two-tailed test even though it is being used for a one directional assessment in many cases. This raises the threshold of significance considerably. The value of 1.96 is the number of standard deviations across a distribution that contains 95% of the data with 2.5 % above and below the defined interval. This gives the 95% confidence interval for a two-tail distribution. If a one tail distribution is chosen because it is a one-direction effect, then the lowest limit is 1.65 standard deviations and the upper limit is infinity. Hence for a 1-tail 95% confidence Interval lower limit is 95% CI = exp [loge RR - 1.65 √(1/A + 1/C)] For most studies the limiting factor in reaching the significance level is the small number of the incidence populations (A or C). This is illustrated by the following example: A study involves two groups of Np =1000 person-years. One group is exposed and one is not exposed but is similar in all other aspects. The biological effect is measured in 24 of the exposed group and 12 of the unexposed group. The statistical analysis using the EPI6 program is Np=1000 N=24 RR = 2.00 95%CI: 1.01 - 3.98 p = 0.044
12 size. All have the same RR value indicating a doubling of the disease rate. The only factor that is changed is the sample size. When each group contains 500 people the result is insignificant, with 1000 it is significant (p
Page 1 and 2: Epidemiological Principles for ELF
Page 3 and 4: 2 Kingdom; Professor Abraham Lilien
Page 5 and 6: 4 causing the disease. For each of
Page 7 and 8: 6 “Once again looking at the obve
Page 9 and 10: 8 A case-control study looks back a
Page 11: 10 Figure 2: The basic design of a
Page 15 and 16: 14 Table 4: An example, with a tren
Page 17 and 18: Occupational Risk Assessment: 16 If
Page 19 and 20: 18 The significant drop in dielectr
Page 21 and 22: 20 These biophysics relationships s
Page 23 and 24: 22 For EMR the mean operational exp
Page 25 and 26: 24 Almost all residential studies o
Page 27 and 28: 26 An independent comparison in ava
Page 29 and 30: Broadcast Tower Epidemiological Stu
Page 31 and 32: 30 However, no other site than Birm
Page 33 and 34: 32 0.155, or relative gains of 1.0,
Page 35 and 36: 34 showing the frequency dependence
Page 37 and 38: 36 Figure 23 shows that the general
Page 39 and 40: 38 other health effects being shown
Page 41 and 42: 40 Figure 29: Age-specific death ra
Page 43 and 44: 42 between the UK and the US. It al
Page 45 and 46: 44 traffic. The cases and controls
Page 47 and 48: 46 The greater strength of evidence
Page 49 and 50: 48 yrs. When using a risk assessmen
Page 51 and 52: 50 Conclusions and Recommendations:
Page 53 and 54: 52 For residential radio-frequency
Page 55 and 56: 54 Haines, C., Kaune, W.T., Friedma
Page 57 and 58: 56 Nicholas, J.S., Lackland, D.T.,

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