南京市区呼吸系统疾病死亡与气温的关系

目的 了解气温对南京市居民呼吸系统疾病死亡的影响特点,以采取有针对性的预防措施,减少因气温变化导致的呼吸系统疾病的死亡.方法 回顾性采集南京市2003-2009年病伤死因年报表中因呼吸系统疾病死亡的居民死亡资料和对应年度气象资料,分析气温与呼吸系统疾病月死亡人数的相关性,再以月死亡人数为因变量,各气象因子为自变量进行线性回归分析.结果 月平均气温、月平均最高气温、月平均最低气温与呼吸系统疾病月死亡人数均呈负相关,其中月死亡人数与月平均最高气温负关联性最强(r=-0.796,P＜0.01);65岁及以上的老年人群与气象因素的相关性更为显著;月死亡人数随月平均气温的升高死亡人数逐渐降低(β=-0.709,P＜0.01).结论 气温越低,呼吸系统疾病死亡人数越多.     

中国北方高寒地区典型城市低温对城区人口死亡的影响

目的通过对哈尔滨市人口死亡与气温相关性分析探讨低温对不同病种死亡的影响。方法以哈尔滨市某城区为任务地区，研究气温对人口死亡的影响。分析哈尔滨市的气侯特点，分析1998—2005年冬季每日的最高、最低、平均气温及每日人口死亡率。以历年寒流冲击日的冬季为例，分别分析日平均气温、日最高气温、日最低气温与日总死亡数、分病种死亡数的关系。结果哈尔滨市冬季低温多出现在12、1月份，1998—2005年8年的统计资料最低可达-37．3℃。该地区冬季气温在-19℃以下时，随温度降低死亡数显著增加（P=0．005，R^2=0．027），日均超额死亡数有统计学意义；冠心病、脑栓塞在低于-19℃时的日均超额死亡数有统计学意义（P=0．030，R^2=0．042）。结论哈尔滨的人口死亡有2．7％归因于温度，呈低度相关。临界值为-19℃，“寒冷”对冠心病、脑栓塞患者的冲击力更大。     

2000-2004年广州市某城区气温变化与居民死亡的关系分析

[目的]探讨气温对城区居民死亡的影响。[方法]收集2000-2004年广州市某城区居民死亡资料和相应时段的气象资料,分析热日、冷日、平日3类天气情况下居民死亡及死因的变化。[结果]广州市某区2000-2004年合计死亡15802例。月死亡率为40．79／10万～89．46／10万（62．25／10万±9．22／10万）;同期月平均气温为（13．6～30．5）℃（22．9±5．3）℃。观察期间,逐月死亡率与月平均气温呈负相关（r=-0．59,P〈O．01）。死亡率在冬季最冷月（1月）前后达最高峰．其他季节波动不大,在夏季最热月（8月）前后形成1个相对高峰。夏季最高气温在34℃以上时。随气温的升高死亡率显著增加;冬季最低气温在10℃以下时,死亡率显著增加。不同日均气温条件下,居民前5位死因中恶性肿瘤死亡数占全死因死亡数比例的差异有统计学意义（P〈0．05）。2004年6月27日至7月3日持续高温,6月25日至7月9日的半月内居民3日平均死亡30．6例,是当年夏季3日平均死亡数（24．1例）的1．27倍。[结论]广州市城区气温变化对某区居民死亡有显著影响,居民死亡率在气温高或气温低时均呈升高趋势。     

不同温度指标与宁夏5市居民非意外死亡的关系

[目的]探讨不同温度指标与宁夏5市居民非意外死亡的关系。[方法]收集2010年1月1日—2015年12月31日宁夏5市的居民死亡监测数据及气象监测数据,采用广义线性模型结合分布滞后非线性模型,评估不同温度指标与非意外死亡的关系。[结果]宁夏各地区日平均气温的中位数为9.1~12.6℃。相对于日间温差,各地区日内温差的中位数更大,无论是高温天气(当天气温高于最小死亡温度)还是低温天气(当天气温低于最小死亡温度),中卫市的日内温差最大(高温天气:13.8℃;低温天气:13.5℃)。宁夏各地区日平均气温与非意外死亡之间呈现"V"或"J"型关系,极端低温(日平均气温的第1百分位数)增加银川市(RR:1.69;95%CI:1.31~2.19)、石嘴山市(RR:2.03;95%CI:1.04~3.93)及固原市(RR:2.16;95%CI:1.53~3.04)居民非意外死亡的风险。极端高温(日平均气温的第99百分位数)增加吴忠市(RR:2.49;95%CI,1.20~5.14)居民非意外死亡的风险。高温天气时,日内温差增加可增加银川市居民的死亡风险(RR:1.06;95%CI:1.01~1.11)。日间温差的变化对宁夏地区居民非意外死亡的影响无统计学意义。[结论]相较于日内温差及日间温差,日平均气温过高或过低对宁夏地区居民非意外死亡风险的影响更大。     

气象因素对沈阳市城市居民死亡的影响

目的探讨气象因素对沈阳城市居民死亡的影响,以便开展针对性的防控措施。方法收集2014年1月1日—2017年12月31日沈阳市五城区日死亡监测数据和气象监测数据,分析各气象因素与疾病日死亡人数的相关关系,评估气象要素对居民死亡的影响,并构建回归方程进行预警预测。结果 2014—2017年沈阳市五城区居民死亡132 327例,日均死亡人数为90.6人;传染病和寄生虫、损伤和中毒日均死亡人数与所有气象因素均无相关性;全死因日均死亡人数与气压呈正相关(r=0.277,P0.01),与气温(r=-0.301,P0.01)、日照时数(r=-0.072,P0.05)、蒸发量(r=-0.241,P0.01)及水气压(r=-0.342,P0.01)呈负相关;后退法多因素回归分析发现大风(β=0.063,P0.05)和低温(β=-0.387,P0.01)天气会造成死亡人数显著上升,低温对循环系统疾病和呼吸系统疾病死亡的影响尤为明显,回归系数分别为-0.254和-0.356(均P0.01);水汽压与呼吸系统疾病死亡的回归系数为正(β=0.193,P0.01),与循环系统疾病和内分泌及代谢类疾病死亡负相关,回归系数分别为-0.232和-0.201。结论低温、高湿、大风会导致循环系统疾病死亡和呼吸系统疾病死亡显著增加,气象因素是影响2014—2017年沈阳市城市居民死亡的重要因素。     

南京市气象因素对居民心血管疾病死亡的影响

目的 通过研究气象因素对心血管疾病死亡风险的影响,为患病居民提供应对气候变化的针对性预防措施,从而帮助患者有效延长存活期、提高生存质量.方法 采用回顾性调查的方法收集资料,分析南京城区2003-2007年气候变化对居民心血管疾病死亡的影响.分析各气象因素与疾病日死亡人数的相关关系,并进行曲线估计分析.结果 南京市区2003-2007年居民心死亡人数有所上升,但死亡率无上升趋势(x2势=3.71,P=0.054).夏季,当日最高温度高于32℃时,心血管疾病的死亡人数增加(Z =9.24,P=0.001);冬季,随着日最低温度的降低,心血管疾病死亡人数逐渐增加,但是没有死亡人数明显增加温度转折点.平均气压与之呈正相关(r=0.27,P=0.001);相对湿度(r=-0.04,P=0.00l)、降水量(r=-0.12,P=0.001)与心血管疾病死亡呈负相关.结论 夏季心血管疾病死亡人数明显增多的日最高温度的临界值是32℃,低气压、潮湿的环境会增加心血管疾病的死亡人数.     

犬猫伤人次数与气象要素关系初步研究

目的通过分析犬、猫伤人事件的时间分布特点及与各气象要素的关系,为居民饲养宠物及防范自身安全提供参考。方法收集北京市某医院2008—2011年犬伤人(咬伤/抓伤)61 883例及2008—2009年猫伤人(咬伤/抓伤)1 878例的急诊就诊资料,与同期气象资料进行相关分析,并用逐步回归法建立犬、猫日伤人次数的预报方程。结果犬伤人次数的年分布曲线为单峰型,夏季最高,占总就诊人数的32.3%;春、秋季次之,分别占23.7%和25.5%;冬季最低,占18.6%。猫伤人事件在夏、秋季均处于高发期,分别占32.8%和30.2%;冬、春季为低发期,合计占37.0%。犬伤人次数与日平均气温、日最高气温、日最低气温、相对湿度、降水量均呈正相关(r值分别为0.70,0.68,0.70,0.37,0.18,均P=0.000);与日平均气压、日最高气压、日最低气压、风速均呈负相关(r值分别为-0.59,-0.62,-0.57,-0.12,均P=0.000)。猫伤人次数与日平均气温、日最高气温、日最低气温、相对湿度、日照时数均呈正相关(r值分别为0.303,0.296,0.318,0.237,0.097,均P=0.000);与日平均气压、日最高气压、日最低气压、风速均呈负相关(r值分别为-0.260,-0.268,-0.249,-0.084,均P=0.000)。结论犬、猫伤人次数可能与气象要素有关,应加强防范。     

气象因素对上海市长宁区脑卒中死亡的影响

目的 探索气象因素对脑卒中死亡的影响。方法 收集2004—2016年上海市长宁区脑卒中患者死亡数据以及同期气象数据,分析气象因素对脑卒中患者死亡的影响。结果 脑卒中死亡与平均气温、日照时间、降水量、蒸发量、降雨日都存在负相关关系,与平均气温的相关关系最强(r=-0.71,P<0.001)。在逐步回归模型中,月平均气温每升高1 ℃,当月脑卒中死亡人数减少1.347人(F=156.3,P<0.001)。非参数回归模型显示,气温对脑卒中死亡影响并非呈线性变化,在月均气温小于10 ℃时,月均气温每上升1 ℃,脑卒中死亡人数即可下降1.879人。随着气温的上升,气温对脑卒中死亡的影响逐渐减小,当月平均气温到27 ℃,气温对脑卒中死亡影响达到最低。结论 加强低温和高温季节的脑卒中患者和高危人群的主动预防,完善脑卒中发病人群的救治途径,并且积极提供脑卒中患者病后康复治疗,减少并发症(如致残)的产生,可以降低脑卒中的死亡率。     

基于气象因素的上海市金山区手足口病多元线性回归预测模型

目的应用多元线性回归构建基于气象因素的上海市金山区手足口病预测模型。方法收集上海市金山区2010年至2013年手足口病逐日发病人数与包括日最高气温、日最低气温、日平均气温、日最低相对湿度、日平均相对湿度、日平均气压、日降水量、日平均日照时数、日平均风速在内的9种同期气象资料进行相关分析,并选择相关系数有显著性的气象因素进行手足口病的逐步回归模型构建。结果手足口病发病人数与日最高气温、日最低气温、日平均气温、日平均相对湿度、日最低相对湿度呈正相关性（P<0.05）,与日平均气压、日平均风速呈负相关性（P<0.05）。最终有日平均气压、日平均风速和日最高气温进入模型,回归系数分别为-0.129、-0.299和-0.039,且容忍度与方差膨胀因子均显示模型不存在严重的多重共线性。结论基于气象因素的上海市金山区手足口病预测模型解释性拟合程度较好,可用于短期预测。     

高温对武汉市居民死亡的影响

目的探讨极端高温对武汉市居民死亡的影响。方法通过描述武汉市2003年夏季日最高气温与日死亡数的时间序列,对高温期和非高温期的平均日死亡数进行了比较,分析了夏季日最高气温与逐日死亡率的关系。结果2003年夏季高温期有明显的死亡高峰,高温期日平均总死亡数、60岁及以上老年人、心血管疾病和呼吸系统疾病日平均死亡数显著高于非高温期。高温期超额死亡人数为505人,占该年夏季总死亡数的11.4%。死亡率明显增加的日最高气温临界值是36℃,单位温度死亡危险度为3.995/100万。结论极端高温天气可增加2003年武汉市居民死亡风险,尤其是老年人及患有循环系统和呼吸系统疾病等慢性病者。     

上海市郊区1974—2007年恶性肿瘤死亡分析

[目的]分析1974—2007年上海市郊区恶性肿瘤死亡情况,了解30年中恶性肿瘤死亡的变化趋势。[方法]收集1974—2007年上海市死因登记报告系统的郊区恶性肿瘤死亡病例个案资料,分析其死亡趋势及主要恶性肿瘤死亡情况。[结果]1974—2007年上海市郊区老龄人口呈现逐年增加趋势,2007年上海市郊区>65岁老龄人口为107.77万人,是1974年(29.23万)的3.69倍;2007年上海市郊区老龄系数达到14.23%,是1974年(5.74%)的2.48倍;从1985年起,老龄系数即超过7%的老龄化社会标准。1974—2007年上海市郊区恶性肿瘤粗死亡率呈显著上升趋势,2007年上海市郊区恶性肿瘤粗死亡率(213.78/10万)是1974年(110.23/10万)的1.94倍;老龄系数与恶性肿瘤死亡率之间有明显线性相关关系。[结论]1974—2007年上海郊区恶性肿瘤标化死亡率表现出平稳下降趋势,但由于上海市老龄程度的不断提高,死亡率仍保持显著上升趋势,说明老龄人口比例增加是恶性肿瘤粗死亡率逐年增加的主要因素之一。随着人口老龄化社会的到来,以恶性肿瘤为主的肿瘤已成为危害人群健康特别是中老年人群健康的主要慢性疾病,应针对上海市的典型老龄化人口特征,结合老年人各部位肿瘤的发病特点,确定肿瘤防治、危险因素研究的重点和对策。     

2007-2017年济南市家庭燃煤导致的一氧化碳中毒时空特征分析

目的 分析2007-2017年济南市因燃煤导致的非职业性一氧化碳（CO）中毒的时空特征，以便有针对性的探讨可行的预防和干预措施。方法 对2007-2017年济南市因燃煤导致的非职业性一氧化碳中毒事件进行描述性分析。结果 2007-2017年济南市共报告因燃煤导致的非职业性一氧化碳中毒事件3153起，发病病例4403例（年均发病率为5.99/10万），死亡病例154例（年均死亡率为2.09/100万），病死率为3.50%。报告事件最多的区县为市中区:事件数572起（18.14%），病例数763例（17.33%），死亡数19例（12.34%），但发病率最高的区县是济阳县（12.09/10万）。2007-2017年之间，报告事件数整体呈下降趋势。事件主要集中在11-3月份，在1月份时达到高峰，且在24小时内有明显的时间分布趋势，事件主要集中在06:00-08:59时间段。非职业性一氧化碳中毒事件数与天气温度呈负相关。结论 2007-2017年济南市非职业性一氧化碳中毒事件起数多，分布广，虽然整体呈下降趋势，但偶有升高，表明群众的防范意识还不够，预防控制工作还需要进一步加强。     

Temperature, housing, deprivation and their relationship to excess winter mortality in Great Britain, 1986-1996.

OBJECTIVES: To examine the associations between temperature, housing, deprivation and excess winter mortality using census variables as proxies for housing conditions. DESIGN: Small area ecological study at electoral ward level. Setting Great Britain between 1986 and 1996. PARTICIPANTS: Men and women aged 65 and over. MAIN OUTCOME MEASURES: Deaths from all causes (International Classification of Diseases, Ninth Revision [ICD-9] codes 0-999), coronary heart disease (ICD-9 410-414), stroke (ICD-9 430-438) and respiratory diseases (ICD-9 460-519). Odds of death occurring in winter period of the four months December to March compared to the rest of the year. RESULTS: During the study period (excluding the influenza epidemic year of 1989/90), a total of 1,682,687 deaths occurred in winter and 2,825,223 deaths occurred during the rest of the year among people aged > or =65 (around 30,000 excess winter deaths per year). A trend of higher excess winter mortality with age was apparent across all disease categories (P < 0.01). There was a significant association between winter mortality and temperature with a 1.5% higher odds of dying in winter for every 1 degrees C reduction in 24-h mean winter temperature. The amount of rain, wind and hours of sunshine were inversely associated with excess winter mortality. Selected housing variables derived from the English House Condition Survey showed little agreement with census-derived variables at electoral ward level. For all-cause mortality there was little association between deprivation and excess winter mortality, although lack of central heating was associated with a higher risk of dying in winter (odds ratio [OR] = 1.016, 95% CI : 1.009-1.022). CONCLUSIONS: Excess winter mortality continues to be an important public health problem in Great Britain. There was a strong inverse association with temperature. Lack of central heating was associated with higher excess winter mortality. Further work is needed to disentangle the complex relationships between different indicators of housing quality and other measures of socioeconomic deprivation and their relationship to the high number of excess winter deaths in Great Britain.     

Mortality related to cold and air pollution in London after allowance for effects of associated weather patterns.

We looked for atypical weather patterns that could confound, and explain large inconsistencies in, conventional estimates of mortality due to SO(2), CO, and smoke. Using Greater London data for 1976-1995 in the linear temperature/mortality range 0-15 degrees C we determined weather patterns associated with pollutants (all deseasonalized) by single regressions of daily temperature, wind, rain, humidity, and sunshine at successive days advance and delay. Polluted days were colder (P<0.01 for SO(2), CO, and smoke) and less windy and rainy than usual, and this cold weather was more prolonged than usual with 50% maximum temperature depression 5.9 days (95% interval 4.0-7.7) before high SO(2), compared to 2.0 (1.6-2.3) days before average cold days. We also used multiple regression of mortality at 50+ years of age on all these weather factors and pollutants at 0-, 1-, 2- to 4-, 5- to 13-, and 14- to 24-day delays to allow for the atypical weather patterns. This showed cold weather associated with 2.77 excess deaths per million during 24 days following a 1 degrees C fall for 1 day, but no net excess deaths with SO(2) (mean 28.0 ppb) or CO (1.26 ppm). It suggested (P>0.05) some increase with smoke, perhaps acting as surrogate for PM(10), for which data were too scanty to analyze.     

南方低温雨雪冰冻灾害的疾病负担研究

目的评估低温雨雪冰冻灾害可能造成的健康损失,为采取针对性的预防和减轻措施提供依据。方法收集了我国南方某省CZ市SX区1月13日到2月8日灾害期间主要医疗机构的临床记录,筛查其中死亡、骨折、一氧化碳中毒和心脏病急性发作等病例,并以人口普查资料作为计算本次发生率的分母,对灾害期数据与前两年同期数据进行了比较。结果与2006-2007年同期相比,灾害期间被调查地区的超额死亡率为0.98/10 000,其中循环系统和CO中毒的超额死亡率分别为0.49/10 000和0.35/10 000;与2004-2007年同期相比,灾害期间被调查地区主要与灾害有关的传染病超额发病率为-3.75/100 000;与2007年同期相比,灾害期间被调查地区急救转运病例发生率增加了0.98‰,医疗机构门诊就诊率下降了2.1‰,而急诊科门诊就诊率增加了0.08‰;医疗机构病人住院率下降了0.11‰,而CO中毒和骨折病人住院率分别增加了0.41‰和0.16‰。结论低温雨雪冰冻灾害增加了CO中毒、骨折和循环系统等特殊疾病的死亡率或发病率。有必要采取措施,预防和缓解和寒冷有关的疾病,特别是一氧化碳中毒的发生。     

Effects of the summer heat wave of 1988 on daily mortality in Allegheny County, PA

The authors studied total mortality in Allegheny County, PA, during the summer of 1988. A heat wave occurred in July of 1988, with daily maximum temperatures near or above 90 degrees Fahrenheit on 15 consecutive days. During that period there were a total of 694 deaths from all causes in the county, compared with an expected 587 deaths (P less than .01). All 107 excess deaths were of persons ages 65 or older, with the majority (78) occurring to persons older than age 75. Daily mortality was most closely correlated with average temperature from the previous day (R = .49, P less than .01), suggesting the cumulative effects of successive high daytime and night-time temperatures on susceptible persons. Evaluation of a possible effect on mortality of high ambient ozone levels detected in early July suggested that ozone did not contribute to excess mortality during the heat wave. Comparison of the 1988 heat wave with a less intense hot spell of 1973 indicated that excess mortality was less than would have been expected in 1988. The authors speculate that increased public awareness and the wider use of air conditioning over the years may have reduced the lethality of periods of extreme summer temperatures in urban areas. Further research is needed to evaluate this hypothesis completely. Public health officials should continue to monitor weather forecasts for predictions of extended periods of unusual heat and should warn the public to take suitable precautions during such periods.     

Excess deaths during the August 2003 heat wave in Paris, France

BACKGROUND: During the August 2003 heat wave in France, almost 15,000 excess deaths were recorded. Paris was severely affected, with an excess death rate of 141%. This study had two aims: to identify individual factors associated with excess deaths during a heat wave in an urban environment and to describe the spatial distribution of deaths within the French capital. METHODS: The study population included all people who died at home between August 1st and 20th, 2003 (N=961). We identified factors associated with excess deaths by comparing the sociodemographic characteristics of the study population with those of people who died at home during the same period in reference years (2000, 2001, 2002) (N=530). Spatial differences were analysed by calculating comparative mortality rates within Paris during August 2003. Mortality ratio was determined to demonstrate temporal variations in mortality between the heat wave period and reference years. RESULTS: The major factors associated with excess death were: age over 75 years (adjusted OR=1.44 (1.10-1.90), being female (adjusted OR=1.43 (1.11-1.83)), not being married (adjusted OR=1.63 (1.23-2.15)), particularly for men. Being a foreigner appeared to be a protective factor for women. Comparative mortality rates by neighbourhood showed a gradient in excess deaths from North-West to South-East. The mortality ratio was 5.44 (5.10-5.79), with very high rates of excess death in the South (12th, 13th, 14th and 15th "arrondissement"). CONCLUSION: The August 2003 heat wave in Paris was associated with both an exceptional increase in mortality rates and changes in the characteristics of those dying and spatial distribution of mortality. Understanding the effects of a heat wave on mortality can probably be improved by an analysis of risk at two levels: individual and contextual.     

Study on the association between ambient air pollution and daily cardiovascular and respiratory mortality in an urban district of Beijing

The association between daily cardiovascular/respiratory mortality and air pollution in an urban district of Beijing was investigated over a 6-year period (January 2003 to December 2008). The purpose of this study was to evaluate the relative importance of the major air pollutants [particulate matter (PM), SO2, NO2] as predictors of daily cardiovascular/respiratory mortality. The time-series studied comprises years with lower level interventions to control air pollution (2003-2006) and years with high level interventions in preparation for and during the Olympics/Paralympics (2007-2008). Concentrations of PM10, SO2, and NO2, were measured daily during the study period. A generalized additive model was used to evaluate daily numbers of cardiovascular/respiratory deaths in relation to each air pollutant, controlling for time trends and meteorological influences such as temperature and relative humidity. The results show that the daily cardiovascular/respiratory death rates were significantly associated with the concentration air pollutants, especially deaths related to cardiovascular disease. The current day effects of PM10 and NO2 were higher than that of single lags (distributed lags) and moving average lags for respiratory disease mortality. The largest RR of SO2 for respiratory disease mortality was in Lag02. For cardiovascular disease mortality, the largest RR was in Lag01 for PM10, and in current day (Lag0) for SO2 and NO2. NO2 was associated with the largest RRs for deaths from both cardiovascular disease and respiratory disease.     

2002-2006年上海市徐汇区60岁及以上老年人伤害死亡分析

[目的]分析2002～2006年上海市徐汇区老年人伤害死亡发生、发展的流行特征和变化趋势，为制定适宜的老年人伤害预防和有效干预措施提供科学依据。[方法]对2002～2006年上海市徐汇区≥60岁户籍老年人伤害死亡资料进行流行病学分析。[结果]5年间伤害死亡率为118．37／10^5，标化死亡率为83．86／10^5，男女性标化死亡率比值是0．74，伤害死亡率随着老年人年龄增长而不断上升。跌倒是老年人群伤害死亡的首因，死亡率达56．36／10^5，占伤害总死亡数的64．87％。不同年龄段人群伤害死因分布特点不同，男女性前5位伤害死因类别相同，但顺位有所不同。[结论]伤害已对老年人造成健康危害和生命影响，必须充分认识到老年人伤害的严重性、危害性和可预防性，有针对性地开展社区老年人伤害的预防与控制工作。     

Low blood pressure and five-year mortality in a Stockholm cohort of the very old: possible confounding by cognitive impairment and other factors.

OBJECTIVES: Low blood pressure has often been reported to be related to excess mortality in people over the age of 75 years. This study examined whether other predictors may account for the association. METHODS: A community-based cohort of 1810 people who were aged 75 years and older was followed for 5 years. RESULTS: The relative risk of death was 1.39 (95% confidence interval [CI] = 1.11, 1.73) for people with systolic pressure lower than 130 mm Hg and 1.21 (95% CI = 1.02, 1.43) for those with diastolic pressure lower than 75 mm Hg, compared with corresponding reference groups, when all other variables were simultaneously considered in Cox proportional hazards models. The observed association was present mainly in subjects with at least two of the three conditions (cardiovascular disease, limitation in activities of daily living, or cognitive impairment). The effect of low diastolic pressure on mortality was also significant in those with only cognitive impairment. CONCLUSIONS: Preexisting cardiovascular disease, limitation in activities of daily living, and, more important, cognitive impairment may be responsible for the association of low blood pressure with increased mortality in the very old in that they cause both reductions in blood pressure and excess deaths.