Dataset Information

Mortality attributable to hot and cold ambient temperatures in India: a nationally representative case-crossover study.

ABSTRACT:

Background

Most of the epidemiological studies that have examined the detrimental effects of ambient hot and cold temperatures on human health have been conducted in high-income countries. In India, the limited evidence on temperature and health risks has focused mostly on the effects of heat waves and has mostly been from small scale studies. Here, we quantify heat and cold effects on mortality in India using a nationally representative study of the causes of death and daily temperature data for 2001-2013.

Methods and findings

We applied distributed-lag nonlinear models with case-crossover models to assess the effects of heat and cold on all medical causes of death for all ages from birth (n = 411,613) as well as on stroke (n = 19,753), ischaemic heart disease (IHD) (n = 40,003), and respiratory diseases (n = 23,595) among adults aged 30-69. We calculated the attributable risk fractions by mortality cause for extremely cold (0.4 to 13.8°C), moderately cold (13.8°C to cause-specific minimum mortality temperatures), moderately hot (cause-specific minimum mortality temperatures to 34.2°C), and extremely hot temperatures (34.2 to 39.7°C). We further calculated the temperature-attributable deaths using the United Nations' death estimates for India in 2015. Mortality from all medical causes, stroke, and respiratory diseases showed excess risks at moderately cold temperature and hot temperature. For all examined causes, moderately cold temperature was estimated to have higher attributable risks (6.3% [95% empirical confidence interval (eCI) 1.1 to 11.1] for all medical deaths, 27.2% [11.4 to 40.2] for stroke, 9.7% [3.7 to 15.3] for IHD, and 6.5% [3.5 to 9.2] for respiratory diseases) than extremely cold, moderately hot, and extremely hot temperatures. In 2015, 197,000 (121,000 to 259,000) deaths from stroke, IHD, and respiratory diseases at ages 30-69 years were attributable to moderately cold temperature, which was 12- and 42-fold higher than totals from extremely cold and extremely hot temperature, respectively. The main limitation of this study was the coarse spatial resolution of the temperature data, which may mask microclimate effects.

Conclusions

Public health interventions to mitigate temperature effects need to focus not only on extremely hot temperatures but also moderately cold temperatures. Future absolute totals of temperature-related deaths are likely to depend on the large absolute numbers of people exposed to both extremely hot and moderately cold temperatures. Similar large-scale and nationally representative studies are required in other low- and middle-income countries to better understand the impact of future temperature changes on cause-specific mortality.

SUBMITTER: Fu SH

PROVIDER: S-EPMC6057641 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mortality attributable to hot and cold ambient temperatures in India: a nationally representative case-crossover study.

Fu Sze Hang SH Gasparrini Antonio A Rodriguez Peter S PS Jha Prabhat P

PLoS medicine 20180724 7

<h4>Background</h4>Most of the epidemiological studies that have examined the detrimental effects of ambient hot and cold temperatures on human health have been conducted in high-income countries. In India, the limited evidence on temperature and health risks has focused mostly on the effects of heat waves and has mostly been from small scale studies. Here, we quantify heat and cold effects on mortality in India using a nationally representative study of the causes of death and daily temperature ...[more]

PMID: 30040816

Similar Datasets

Project description:BackgroundWHO estimates that about 170,000 deaths by suicide occur in India every year, but few epidemiological studies of suicide have been done in the country. We aimed to quantify suicide mortality in India in 2010.MethodsThe Registrar General of India implemented a nationally representative mortality survey to determine the cause of deaths occurring between 2001 and 2003 in 1·1 million homes in 6671 small areas chosen randomly from all parts of India. As part of this survey, fieldworkers obtained information about cause of death and risk factors for suicide from close associates or relatives of the deceased individual. Two of 140 trained physicians were randomly allocated (stratified only by their ability to read the local language in which each survey was done) to independently and anonymously assign a cause to each death on the basis of electronic field reports. We then applied the age-specific and sex-specific proportion of suicide deaths in this survey to the 2010 UN estimates of absolute numbers of deaths in India to estimate the number of suicide deaths in India in 2010.FindingsAbout 3% of the surveyed deaths (2684 of 95,335) in individuals aged 15 years or older were due to suicide, corresponding to about 187,000 suicide deaths in India in 2010 at these ages (115,000 men and 72,000 women; age-standardised rates per 100,000 people aged 15 years or older of 26·3 for men and 17·5 for women). For suicide deaths at ages 15 years or older, 40% of suicide deaths in men (45,100 of 114,800) and 56% of suicide deaths in women (40,500 of 72,100) occurred at ages 15-29 years. A 15-year-old individual in India had a cumulative risk of about 1·3% of dying before the age of 80 years by suicide; men had a higher risk (1·7%) than did women (1·0%), with especially high risks in south India (3·5% in men and 1·8% in women). About half of suicide deaths were due to poisoning (mainly ingestions of pesticides).InterpretationSuicide death rates in India are among the highest in the world. A large proportion of adult suicide deaths occur between the ages of 15 years and 29 years, especially in women. Public health interventions such as restrictions in access to pesticides might prevent many suicide deaths in India.FundingUS National Institutes of Health.

Project description:National malaria death rates are difficult to assess because reliably diagnosed malaria is likely to be cured, and deaths in the community from undiagnosed malaria could be misattributed in retrospective enquiries to other febrile causes of death, or vice-versa. We aimed to estimate plausible ranges of malaria mortality in India, the most populous country where the disease remains common.Full-time non-medical field workers interviewed families or other respondents about each of 122,000 deaths during 2001-03 in 6671 randomly selected areas of India, obtaining a half-page narrative plus answers to specific questions about the severity and course of any fevers. Each field report was sent to two of 130 trained physicians, who independently coded underlying causes, with discrepancies resolved either via anonymous reconciliation or adjudication.Of all coded deaths at ages 1 month to 70 years, 2681 (3·6%) of 75,342 were attributed to malaria. Of these, 2419 (90%) were in rural areas and 2311 (86%) were not in any health-care facility. Death rates attributed to malaria correlated geographically with local malaria transmission ratesderived independently from the Indian malaria control programme. The adjudicated results show 205,000 malaria deaths per year in India before age 70 years (55,000 in early childhood, 30,000 at ages 5-14 years, 120,000 at ages 15-69 years); 1·8% cumulative probability of death from malaria before age 70 years. Plausible lower and upper bounds (on the basis of only the initial coding) were 125,000-277,000. Malaria accounted for a substantial minority of about 1·3 million unattended rural fever deaths attributed to infectious diseases in people younger than 70 years.Despite uncertainty as to which unattended febrile deaths are from malaria, even the lower bound greatly exceeds the WHO estimate of only 15,000 malaria deaths per year in India (5000 early childhood, 10?000 thereafter). This low estimate should be reconsidered, as should the low WHO estimate of adult malaria deaths worldwide.US National Institutes of Health, Canadian Institute of Health Research, Li Ka Shing Knowledge Institute.

Project description:BackgroundMore than 2·3 million children died in India in 2005; however, the major causes of death have not been measured in the country. We investigated the causes of neonatal and child mortality in India and their differences by sex and region.MethodsThe Registrar General of India surveyed all deaths occurring in 2001-03 in 1·1 million nationally representative homes. Field staff interviewed household members and completed standard questions about events that preceded the death. Two of 130 physicians then independently assigned a cause to each death. Cause-specific mortality rates for 2005 were calculated nationally and for the six regions by combining the recorded proportions for each cause in the neonatal deaths and deaths at ages 1-59 months in the study with population and death totals from the United Nations.FindingsThere were 10,892 deaths in neonates and 12,260 in children aged 1-59 months in the study. When these details were projected nationally, three causes accounted for 78% (0·79 million of 1·01 million) of all neonatal deaths: prematurity and low birthweight (0·33 million, 99% CI 0·31 million to 0·35 million), neonatal infections (0·27 million, 0·25 million to 0·29 million), and birth asphyxia and birth trauma (0·19 million, 0·18 million to 0·21 million). Two causes accounted for 50% (0·67 million of 1·34 million) of all deaths at 1-59 months: pneumonia (0·37 million, 0·35 million to 0·39 million) and diarrhoeal diseases (0·30 million, 0·28 million to 0·32 million). In children aged 1-59 months, girls in central India had a five-times higher mortality rate (per 1000 livebirths) from pneumonia (20·9, 19·4-22·6) than did boys in south India (4·1, 3·0-5·6) and four-times higher mortality rate from diarrhoeal disease (17·7, 16·2-19·3) than did boys in west India (4·1, 3·0-5·5).InterpretationFive avoidable causes accounted for nearly 1·5 million child deaths in India in 2005, with substantial differences between regions and sexes. Expanded neonatal and intrapartum care, case management of diarrhoea and pneumonia, and addition of new vaccines to immunisation programmes could substantially reduce child deaths in India.FundingUS National Institutes of Health, International Development Research Centre, Canadian Institutes of Health Research, Li Ka Shing Knowledge Institute, and US Fund for UNICEF.

Project description:ObjectiveTo assess national and regional trends and causes-specific distribution of maternal mortality in India.DesignNationally representative cross-sectional surveys.SettingAll of India from 1997 to 2020.SampleAbout 10 000 maternal deaths among 4.3 million live births over two decades.MethodsWe analysed trends in the maternal mortality ratio (MMR) from 1997 through 2020, estimated absolute maternal deaths and examined the causes of maternal death using nationally representative data sources. We partitioned female deaths (aged 15-49 years) and live birth totals, based on the 2001-2014 Million Death Study to United Nations (UN) demographic totals for the country.Main outcome measuresMaternal mortality burden and distribution of causes.ResultsThe MMR declined in India by about 70% from 398/100 000 live births (95% CI 378-417) in 1997-98 to 99/100 000 (90-108) in 2020. About 1.30 million (95% CI 1.26-1.35 million) maternal deaths occurred between 1997 and 2020, with about 23 800 (95% CI 21 700-26 000) in 2020, with most occurring in poorer states (63%) and among women aged 20-29 years (58%). The MMRs for Assam (215), Uttar Pradesh/Uttarakhand (192) and Madhya Pradesh/Chhattisgarh (170) were highest, surpassing India's 2016-2018 estimate of 113 (95% CI 103-123). After adjustment for education and other variables, the risks of maternal death were highest in rural and tribal areas of north-eastern and northern states. The leading causes of maternal death were obstetric haemorrhage (47%; higher in poorer states), pregnancy-related infection (12%) and hypertensive disorders of pregnancy (7%).ConclusionsIndia could achieve the UN 2030 MMR goals if the average rate of reduction is maintained. However, without further intervention, the poorer states will not.Tweetable abstractWe estimated that 1.3 million Indian women died from maternal causes over the last two decades. Although maternal mortality rates have fallen by 70% overall, the poorer states lag behind.

Dataset Information

Mortality attributable to hot and cold ambient temperatures in India: a nationally representative case-crossover study.

Background

Methods and findings

Conclusions

Publications

Mortality attributable to hot and cold ambient temperatures in India: a nationally representative case-crossover study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets