Nils Skajaa

TY - JOUR

T1 - Lack of seasonality in occurrence of pericarditis, myocarditis, and endocarditis

AU - Skajaa, Nils

AU - Horváth-Puhó, Erzsébet

AU - Adelborg, Kasper

AU - Bøtker, Hans Erik

AU - Rothman, Kenneth R

AU - Sørensen, Henrik Toft

N1 - Copyright © 2019 Elsevier Inc. All rights reserved.

PY - 2019/9

Y1 - 2019/9

N2 - PURPOSE: The etiology of pericarditis, myocarditis, and endocarditis is predominantly infectious, and infections often show seasonal variation. Little is known, however, about seasonal patterns in these cardiopathies.METHODS: Using Danish health care registries, we identified all patients with a first-time hospital-based diagnosis of pericarditis, myocarditis, or endocarditis between 1994 and 2016. We estimated peak-to-trough ratios from fitted sine curves to measure the intensity of seasonal variation in occurrence during the study period. Because randomness will lead to small apparent seasonal patterns, we also conducted a plasmode simulation to assess the degree of seasonality that randomness would produce.RESULTS: Crude peak-to-trough ratios of monthly frequencies summarized over a year were small. We estimated a peak-to-trough ratio of 1.10 (95% confidence interval [CI], 1.05-1.14) for pericarditis, 1.11 (95% CI, 1.02-1.21) for myocarditis, and 1.01 (95% CI, 1.00-1.07) for endocarditis. The simulated mean peak-to-trough ratios found after randomly reassigning the monthly frequencies within each year were 1.04 (95% CI, 1.00-1.09) for pericarditis, 1.04 (95% CI, 1.00-1.13) for myocarditis, and 1.04 (95% CI, 1.00-1.10), for endocarditis.CONCLUSION: The data indicate no important seasonal variation in the occurrence of pericarditis, myocarditis, and endocarditis in Denmark between 1994 and 2016.

AB - PURPOSE: The etiology of pericarditis, myocarditis, and endocarditis is predominantly infectious, and infections often show seasonal variation. Little is known, however, about seasonal patterns in these cardiopathies.METHODS: Using Danish health care registries, we identified all patients with a first-time hospital-based diagnosis of pericarditis, myocarditis, or endocarditis between 1994 and 2016. We estimated peak-to-trough ratios from fitted sine curves to measure the intensity of seasonal variation in occurrence during the study period. Because randomness will lead to small apparent seasonal patterns, we also conducted a plasmode simulation to assess the degree of seasonality that randomness would produce.RESULTS: Crude peak-to-trough ratios of monthly frequencies summarized over a year were small. We estimated a peak-to-trough ratio of 1.10 (95% confidence interval [CI], 1.05-1.14) for pericarditis, 1.11 (95% CI, 1.02-1.21) for myocarditis, and 1.01 (95% CI, 1.00-1.07) for endocarditis. The simulated mean peak-to-trough ratios found after randomly reassigning the monthly frequencies within each year were 1.04 (95% CI, 1.00-1.09) for pericarditis, 1.04 (95% CI, 1.00-1.13) for myocarditis, and 1.04 (95% CI, 1.00-1.10), for endocarditis.CONCLUSION: The data indicate no important seasonal variation in the occurrence of pericarditis, myocarditis, and endocarditis in Denmark between 1994 and 2016.

KW - Cardiovascular inflammation

KW - Peak-to-low ratios

KW - Random error

KW - Seasonal variation

U2 - 10.1016/j.annepidem.2019.07.005

DO - 10.1016/j.annepidem.2019.07.005

M3 - Journal article

C2 - 31431396

VL - 37

SP - 77

EP - 80

JO - Annals of Epidemiology

JF - Annals of Epidemiology

SN - 1047-2797

ER -