Sethi Dheeraj K, Rhodes James, Ferris Rebecca, Banka Radhika, Clarke Allan, Mishra Eleanor K
Norwich Medical School, University of East Anglia, Norwich, GBR.
Respiratory Medicine, Norfolk and Norwich University Hospital, Norwich, GBR.
Cureus. 2023 May 18;15(5):e39192. doi: 10.7759/cureus.39192. eCollection 2023 May.
Breathlessness is a commonly encountered symptom, and although its relationship with mortality is well established for many conditions, less clear is this relationship in healthy adults. This systematic review and meta-analysis examines whether breathlessness is associated with mortality in a general population. This is important in understanding the impact of this common symptom on a patient's prognosis. This review was registered with PROSPERO (CRD42023394104). Medline, EMBASE, CINAHL and EMCARE were searched for the terms 'breathlessness' and 'survival' or 'mortality' on January 24, 2023. Longitudinal studies of >1,000 healthy adults comparing mortality between breathless and non-breathless controls were eligible for inclusion. If an estimate of effect size was provided, studies were included in the meta-analysis. Eligible studies underwent critical appraisal, data extraction and risk of bias assessment. A pooled effect size was estimated for the relationship between the presence of breathlessness and mortality and levels of severity of breathlessness and mortality. Of 1,993 studies identified, 21 were eligible for inclusion in the systematic review and 19 for the meta-analysis. Studies were of good quality with a low risk of bias, and the majority controlled for important confounders. Most studies identified a significant relationship between the presence of breathlessness and increased mortality. A pooled effect size was estimated, with the presence of breathlessness increasing the risk of mortality by 43% (risk ratio (RR): 1.43, 95% confidence interval (CI): 1.28-1.61). As breathlessness severity increased from mild to severe, mortality increased by 30% (RR: 1.30, 95% CI: 1.21-1.38) and 103%, respectively (RR: 2.03, 95% CI: 1.75-2.35). The same trend was seen when breathlessness was measured using the modified Medical Research Council (mMRC) Dyspnoea Scale: mMRC grade 1 conferred a 26% increased mortality risk (RR: 1.26, 95% CI: 1.16-1.37) compared with 155% for grade 4 (RR: 2.55, 95% CI: 1.86-3.50). We conclude that mortality is associated with the presence of breathlessness and its severity. The mechanism underlying this is unclear and may reflect the ubiquity of breathlessness as a symptom of many diseases.
呼吸困难是一种常见症状，尽管在许多疾病中其与死亡率的关系已得到充分证实，但在健康成年人中这种关系尚不清楚。本系统评价和荟萃分析探讨了在普通人群中呼吸困难是否与死亡率相关。这对于理解这种常见症状对患者预后的影响很重要。本评价已在国际前瞻性系统评价注册库（PROSPERO，注册号：CRD42023394104）登记。于2023年1月24日在医学主题词表（Medline）、荷兰医学文摘数据库（EMBASE）、护理学与健康领域数据库（CINAHL）和循证医学与卫生保健数据库（EMCARE）中检索了“呼吸困难”和“生存”或“死亡率”等术语。纳入了对1000名以上健康成年人进行的纵向研究，比较有呼吸困难和无呼吸困难对照组的死亡率。如果提供了效应量估计值，则将研究纳入荟萃分析。对符合条件的研究进行了严格评价、数据提取和偏倚风险评估。对呼吸困难的存在与死亡率之间以及呼吸困难的严重程度与死亡率之间的关系估计了合并效应量。在检索到的1993项研究中，21项符合纳入系统评价的条件，19项符合纳入荟萃分析的条件。研究质量良好，偏倚风险较低，大多数研究对重要的混杂因素进行了控制。大多数研究发现呼吸困难的存在与死亡率增加之间存在显著关系。估计了合并效应量，呼吸困难的存在使死亡风险增加43%（风险比（RR）：1.43，95%置信区间（CI）：1.28 - 1.61）。随着呼吸困难严重程度从轻度增加到重度，死亡率分别增加30%（RR：1.30，95% CI：1.21 - 1.38）和103%（RR：2.03，95% CI：1.75 - 2.35）。当使用改良的医学研究委员会（mMRC）呼吸困难量表测量呼吸困难时，也观察到了相同的趋势：与mMRC 4级相比，1级使死亡风险增加26%（RR：1.26，95% CI：1.16 - 1.37），而4级使死亡风险增加155%（RR：2.55，95% CI：1.86 - 3.50）。我们得出结论，死亡率与呼吸困难的存在及其严重程度相关。其潜在机制尚不清楚，可能反映了呼吸困难作为许多疾病症状的普遍性。
