Per gender, the brand new record price is actually demonstrated using city, logarithm regarding hit ages split up because of the 70, and you can piecewise quadratic qualities of age from the publicity joining efficiently in the age 29 and you may fifty
The entire strategy for that it investigation would be to match activities similar to the people that have in past times come put on strong cyst incidence (1) and you may leukemia mortality (23), and you can sample perhaps the record and you can/otherwise rays-relevant excess exposure areas of those individuals activities differed anywhere between first and you will next cancers. Person-ages (PY) at risk and you can counts regarding first and you may second first cancers circumstances have been cross-classified from the pursuing the details: projected rays dosages to your anus and you can marrow (21 kinds for each and every: 0–4, 5–twenty four, 25–49, 50–74, 75–99, 100–124, 125–149, 150–174, 175–199, 200–249, 250–299, 300–499, 500–749, 750–999, step 1,000–step one,249, step one,250–step 1,499, 1,500–step one,749, step one,750–1,999, dos,000–2,499, 2,500–2,999, and you can ?step 3,100 mGy), urban area (c = ?1/2 to possess Hiroshima, +1/2 to have Nagasaki), intercourse (s = ?1/dos for men, +1/dos for women), many years at the time of the new bombing (fifteen categories: 0–4, 5–nine, …, 65–69, ?70), reached years (17 kinds: 5–nine, 10–fourteen, …, 80–84, ?85), diary go out (10 classes: 1958–1960, 1961–1965, …, 1991–1996, and 1997–2002), follow-upwards period (P = a couple of to possess ahead of first first cancer medical diagnosis or >180 weeks after earliest medical diagnosis, respectively), and you can follow-up time (9 groups: 0–4, 5–nine, …, 35–39, and ?forty years since the beginning of pursue-upwards months). At exactly the same time, new pursue-upwards period having second cancer tumors try then mix-tabulated of the ages initially disease medical diagnosis (fifteen classes: 0–4, 5–nine, …, 65–69, ?70) and you will, getting analyses out-of second first cancer tumors pursuing the specific very first disease sizes, by the version of first cancer tumors (tummy, lung, colon, the liver, breast, non-Hodgkin lymphoma, leukemia, thyroid, kidney, or any other). For each and every of them muscle, this new amounts of primary cancer of different items was calculated, also the imply beliefs regarding projected rectum and you can marrow doses (generically denoted d), many years during the time of new bombing (e), attained age (a), follow-up go out (t) and you will, into the next cancers realize-right up several months, indicate decades to start with prognosis (f) and you may mean-time as the basic analysis (m).
Records costs having strong tumors was indeed modeled due to the fact intercourse-particular parametric attributes from area, attained ages, and you can ages at coverage (equivalent to delivery cohort)
Poisson regression analysis was used to estimate and compare the radiation dose-responses for first and second primary cancers. The number of obsługa hi5 cases for a given cancer type was assumed to be a Poisson variate with mean ?d,c,s,a great,elizabeth,t,p,f,m = PYd,c,s,good,e,t,p,f,yards ? d,c,s,good,age,t,p,f,m, where PY denotes person years (PY) at risk and ? the incidence rate. Risk was represented by linear excess relative risk (ERR) models of the form ? d , c , s , a , e , t , p , f , m = ? 0 ( c , s , a , e , t , p , f , m ) [ 1 + E ? R ? R ( d , c , s , a , e , t , p , f , m ) ] or excess additive risk (EAR) models of the form ? d , c , s , a , e , t , p , f , m = ? 0 ( c , s , a , e , t , p , f , m ) + E ? R ? R ( d , c , s , a , e , t , p , f , m ) where ?0(.) is the background cancer incidence rate for subjects with zero dose, and ERR(.) and EAR(.) are the ERR and EAR associated with dose d.
Analyses of solid cancer incidence were based primarily on linear ERR models, although EAR models were also fit. A smooth piecewise quadratic function with knots at e1 and e2 can be written as Q(e) = ?1e + ?2e 2 + ?3max(e ? e1,0) 2 + ?3max(e ? e2,0) 2 . To compare first and second primary cancers, coefficients of the terms in the background model were allowed to differ according to follow-up period, and an additional term was included for age at diagnosis of first primary cancer (centered at age 55). The general model for background incidence rates in the analysis of all solid tumors was therefore ? 0 ( c , s , a , e , p , f ) = exp [ ? s , p + ? c , s , p c + ? a , s , p ln ( a / 70 ) + Q s , p ( e ) + ? f , s , p I ( P = 3 ) ( f ? 55 ) ] where I(.) is the indicator function and Qs,p(.) denotes different piecewise quadratic functions for each (s,p). Analyses of specific solid tumors such as stomach or lung cancer were based on smaller numbers of cases, especially for second primary cancers; therefore, these analyses used a simpler background model in which the effect of age at exposure was represented by terms of the form ?elizabeth,s,pln(e/30) rather than the piecewise quadratic terms Qs,p(e). Differences in background rates of first and second prieter values for p = 1 and p = 2.
