Proportionate incidence ratio

Standardized Proportionate Incidence Ratio (SPIR)—Similar to a Proportionate Mortality Ratio (PMR) in that it is a ratio of a proportion of a specific disease in an exposed group compared with the proportion in an unexposed group. 

In a proportionate mortality or proportionate incidence study, one compares the proportion of deaths or incident cases due to a condition of interest with that expected based on deaths or incident cases in an external, usually the general, population. When the proportions of causes of death are compared, the ratio is known as the proportionate mortality ratio (PMR). The comparison of proportions of incident cases is known as the proportionate incidence ratio (PIR). Proportional measures can be misleading since a decrement in the proportion of deaths or incident cases due to a particular cause will de facto lead to an increase in the proportion due to another cause. The commonly held view with regard to PMRs is that they are good approximations to SMRs from cohort studies when the cohort s all-canses combined SMR is equal to 1.0 (Checkoway et al. 1989). The odds ratio has also been used as a measure of association in PMR or PIR studies and may be a more appropriate measure of association for evalnating proportional measures (WHO 1999). 

PEL Pg pmol PHS PMR ppb ppm ppt REL RfD RTECS sec SCE SIC SIR SMR STEL STORET TLV TSCA TRI TRS TWA u.s. UF yr WHO wk permissible exposure limit picogram picomole Public Health Service proportionate mortality ratio parts per billion parts per million parts per trillion recommended exposure limit Reference Dose Registry of Toxic Effects of Chemical Substances second sister chromatid exchange Standard Industrial Classification Standardized incidence ratio standard mortality ratio short term exposure limit STORAGE and RETRIEVAL threshold limit value Toxic Substances Control Act Toxics Release Inventory total reduced sulfur time-weighted average United States uncertainty factor year World Health Organization week... 

As the attenuation of the incident beam per unit path through the solution, the turbidity is larger than the Rayleigh ratio by the factor Ibrr/S, since T is obtained by integrating Rg over a spherical surface. Thus, if Eq. (10.54) is written in terms of Rg rather than r, the proportionality constant H must also be decreased by l6n/3, in which case the constant is represented by the symbol K ... 

In order to place these relative intensities on an absolute scale, thus obtaining the constants of proportionality cr0(3p4 2s+1Le) of equ. (5.84), a double ZEKE coincidence spectrum of helium was also measured. The ratio of observed argon-to-helium intensities then depends on the constants a0, the numbers Nph of incident photons, and the target densities nv. One has... 

Fig. 5.16 shows the spectral irradiance E according to (5.37) for T = 1000 K and T = 5777 K. Here, the proportionality constants c were each chosen so that for both temperatures the maximum of E, which appears at Amax = C2/5T, was the same. The hatched areas in Fig. 5.16 are proportional to the absorbed fraction of the incident radiation flow, whilst the areas under the E curves correspond to the irradiance E. The desired hemispherical total absorptivity a T) is, according to (5.28) and (5.36) the ratio of these areas. For T = 1000 K an absorptivity close to a 2 will be expected. In contrast the largest portion of the solar radiation (T = 5777 K) falls in the region of small wavelengths... 

With the intensities obtained in Eqs. (84)-(86) we evaluate the probability of hole annihilation due to the second-order process. The probability of the ionization of the atom by an incident electron is determined by the corresponding integral intensity of the first-order process. An estimate of this probability has been made already. Then the probability of the radiationless annihilation of the electron-hole pair created in the atom upon interaction with the incident electron is determined by the ratio between the integral intensities of the first- and second-order processes, Ja /Ja This probability is determined as /Ja 0( rianpC, up to a constant that depends only slightly on the type of the wave function of the core electron. With the expressions obtained, we have determined the value of the constant of proportionality 0.6,0.4, and 0.5 for... 

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