Andrew M T L Choong1, Jack Marjot2, Ian J Y Wee3, Nicholas Syn4, Tom Marjot5, Robert E Brightwell6, Philip J Walker7. 1. SingVaSC, Singapore Vascular Surgical Collaborative, National University of Singapore, Singapore; Cardiovascular Research Institute, National University of Singapore, Singapore; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Division of Vascular Surgery, National University Heart Centre, Singapore. Electronic address: suramctl@nus.edu.sg. 2. SingVaSC, Singapore Vascular Surgical Collaborative, National University of Singapore, Singapore; Prince of Wales Hospital, Sydney, Australia. 3. SingVaSC, Singapore Vascular Surgical Collaborative, National University of Singapore, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 4. SingVaSC, Singapore Vascular Surgical Collaborative, National University of Singapore, Singapore. 5. Imperial College Healthcare NHS Trust, London, United Kingdom. 6. SingVaSC, Singapore Vascular Surgical Collaborative, National University of Singapore, Singapore; Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, United Kingdom. 7. Department of Surgery, University of Queensland, Brisbane, Australia; Department of Vascular Surgery, Royal Brisbane and Women's Hospital, Brisbane, Australia.
Abstract
BACKGROUND: Abdominal aortic aneurysms (AAAs) represent a significant burden of disease worldwide, and their rupture, without treatment, has an invariably high mortality rate. Whereas some risk factors for ruptured AAAs (rAAAs) are well established, such as hypertension, smoking, and female sex, the impact of seasonal and meteorologic variables is less clear. We systematically reviewed the literature to determine whether these variables are associated with rAAA. METHODS: Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled proportions and incidence rate ratios (IRRs) for the different months and seasons. Funnel plots were constructed to assess for publication bias. Given the poor methodologic quality of included studies, a sensitivity analysis was performed on better-quality studies, which scored 6 and above of 9 in the author-modified Newcastle-Ottawa Scale. RESULTS: The pooled proportion of rAAA was highest in the autumn season (incidence rate, 26.6%; 95% confidence interval [CI], 25.6%-27.7%; I2 = 15.4%), followed by winter (incidence rate, 26.2%; 95% CI, 24.1%-28.2%; I2 = 72.4%), and lowest in summer (incidence rate, 21.1%; 95% CI, 19.3%-23.0%; I2 = 70.4%). The IRRs of rAAA were -6.9% (95% CI, -9.8% to -3.9%), -19.5% (95% CI, -22% to -16.8%), +10.5% (95% CI, 7.2%-13.9%), and +18.1% (95% CI, 15%-22%) in spring, summer, autumn, and winter compared with the remaining seasons, respectively (all P < .0001), thus affirming existence of seasonal variation. The pooled proportion of rAAA was highest in December (incidence rate, 8.9%; 95% CI, 7.1%-10.9%; I2 = 54.5%) but lowest in July (incidence rate, 5.7%; 95% CI, 4.2%-7.3%; I2 = 54.5%). The IRR was significantly the highest in January (IRR, 1.14; 95% CI, 1.01-1.29; P = .031) but lowest in July (IRR, 0.75; 95% CI, 0.65-0.87; P < .0001). There is also some evidence for a possible association with atmospheric pressure. Associations with temperature and daylight hours, however, are at best speculative. CONCLUSIONS: Autumn and winter are significantly associated with a higher incidence of rAAAs, and autumn is associated with the highest rupture incidence of all the seasons. However, the inability to appropriately control for other confounding factors known to increase the risk of AAA rupture precludes any additional recommendations to alter current provision of vascular services on the basis of these data.
BACKGROUND:Abdominal aortic aneurysms (AAAs) represent a significant burden of disease worldwide, and their rupture, without treatment, has an invariably high mortality rate. Whereas some risk factors for ruptured AAAs (rAAAs) are well established, such as hypertension, smoking, and female sex, the impact of seasonal and meteorologic variables is less clear. We systematically reviewed the literature to determine whether these variables are associated with rAAA. METHODS: Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled proportions and incidence rate ratios (IRRs) for the different months and seasons. Funnel plots were constructed to assess for publication bias. Given the poor methodologic quality of included studies, a sensitivity analysis was performed on better-quality studies, which scored 6 and above of 9 in the author-modified Newcastle-Ottawa Scale. RESULTS: The pooled proportion of rAAA was highest in the autumn season (incidence rate, 26.6%; 95% confidence interval [CI], 25.6%-27.7%; I2 = 15.4%), followed by winter (incidence rate, 26.2%; 95% CI, 24.1%-28.2%; I2 = 72.4%), and lowest in summer (incidence rate, 21.1%; 95% CI, 19.3%-23.0%; I2 = 70.4%). The IRRs of rAAA were -6.9% (95% CI, -9.8% to -3.9%), -19.5% (95% CI, -22% to -16.8%), +10.5% (95% CI, 7.2%-13.9%), and +18.1% (95% CI, 15%-22%) in spring, summer, autumn, and winter compared with the remaining seasons, respectively (all P < .0001), thus affirming existence of seasonal variation. The pooled proportion of rAAA was highest in December (incidence rate, 8.9%; 95% CI, 7.1%-10.9%; I2 = 54.5%) but lowest in July (incidence rate, 5.7%; 95% CI, 4.2%-7.3%; I2 = 54.5%). The IRR was significantly the highest in January (IRR, 1.14; 95% CI, 1.01-1.29; P = .031) but lowest in July (IRR, 0.75; 95% CI, 0.65-0.87; P < .0001). There is also some evidence for a possible association with atmospheric pressure. Associations with temperature and daylight hours, however, are at best speculative. CONCLUSIONS: Autumn and winter are significantly associated with a higher incidence of rAAAs, and autumn is associated with the highest rupture incidence of all the seasons. However, the inability to appropriately control for other confounding factors known to increase the risk of AAA rupture precludes any additional recommendations to alter current provision of vascular services on the basis of these data.
Authors: Irena Kaspar-Ott; Patrick Olschewski; Stephanie Koller; Alexander Hyhlik-Duerr; Elena Streck; Hans-Henning Eckstein; Oksana Radu; Elke Hertig Journal: Heliyon Date: 2022-04-09