Seasonal Variation in Occurrence of Pulmonary Embolism: Analysis of the Database of the Emilia‐Romagna Region, Italy

Abstract

Seasonal variation in the occurrence of cardiovascular and cerebrovascular events, including pulmonary embolism (PE), has been reported; however, recent large-scale, population-based studies conducted in the United States did not confirm such seasonality. The aim of this large-scale population study was to determine whether a temporal pattern in the occurrence of PE exists. The analysis considered all consecutive cases of PE in the database of all hospital admissions of the Emilia Romagna region in Italy at the Center for Health Statistics between January 1998 and December 2005. PE cases were first grouped according to season of occurrence, and the data were analyzed by the chi(2) test for goodness of fit. Then, inferential chronobiologic (cosinor and partial Fourier) analysis was applied to monthly data, and the best-fitting curve for the annual variation was derived. The total sample consisted of 19,245 patients (8,143 male, mean age 71.6+/-14.1 yrs; 11,102 female, mean age 76.1+/-13.7 yrs). Of these, 2,484 were <65 yrs, 5,443 were between 65 and 74, and 11,318 were > or = 75 yrs. There were 4,486 (23.3%) fatal-case outcomes. PE occurred least frequently in spring (n=4,442 or 23.1%) and most frequent in winter (n=5,236 or 27.2%, goodness of fit chi(2)=75.75, p<0.001). Similar results were obtained for subgroups formed by gender, age, fatal/non-fatal outcome, presence/absence of major underlying co-morbid conditions, and specific risk factors. Inferential chronobiological analysis identified a significant annual pattern in PE, with the peak between November and December for the total sample of cases (p<0.001), males (p<0.001), females (p=0.002), fatal and non-fatal cases (p<0.001 for both), and subgroups formed by age (<65 yrs, p=0.012; 65-74 yrs, p<0.001; > or = 75 yrs, p=0.012). This pattern was independent of the presence/absence of hypertension (p=0.003 and p<0.001, respectively), pulmonary disease (p<0.001 and p<0.001, respectively), stroke (p<0.001 and p=0.004, respectively), neoplasms (p=0.005 and p=0.001, respectively), heart failure (p=0.022 and p<0.001, respectively), and deep vein thrombosis (p=0.002 and p<0.001, respectively). However, only a non-statistically significant trend was found for subgroups formed by cases of diabetes mellitus, infections, renal failure, and trauma.

Deep vein thrombosis: Related to anemophilous pollen?

“…We also surveyed the incidence of pulmonary embolism, a fatal complication of DVT, was also lower in summer half than the winter half at the same time in Zhou's report (59.1% in winter half). The result was accorded with previously reported by Fink and Gallerani [10,11] . Second, Zhou et al found that the DVT incidence peaked in March in Hubei Province, China.…”

Recent Change in the Annual Pattern of Sexually Transmitted Diseases in the United States

“…have focused primarily on 24 h and/or seasonal variation in cardiovascular morbidity and mortality (Gallerani et al, 2007;Manfredini et al, 2005aManfredini et al, , 2005bMehta et al, 2005) and annual patterns in common communicable infectious diseases that primarily affect young school children (Shah et al, 2006). This study examined the cyclic variation and time trends in the incidence of chlamydia, gonorrhea, and syphilis in recent years using the SAS Proc MIXED general linear model.…”

Evaluation of meteorological and epidemiological characteristics of fatal pulmonary embolism

“…All of the meteorological parameters have complex biological effects on human bodies (Braga et al 2002;Cagle and Hubbard 2005;Gyllerup 2000); therefore, there is an increasing interest in the connection between environmental-meteorological factors and vascular disease's morbidity and mortality. Reports in the literature suggest that weather changes may play a role in venous thrombotic disease (Stein et al 2004;Boulay et al 2001) and in the occurrence of PE as well (Öztuna et al 2008;Gallerani et al 2007). …”