Health Disparities in Ischaemic Heart Disease Mortality in Hungary From 1970 to 2010: An Age-Period-Cohort Analysis

Background

The objective of this study was to examine long-term trends in rates of ischaemic heart disease (IHD) mortality, a leading cause of mortality in Hungary. The study examined the effects of age, period, and cohort on IHD mortality rates and compared mortality rates between the capital (Budapest) and non-capital counties.

Methods

Data on IHD deaths and population censuses were obtained from the Hungarian Central Statistical Office. Age-period-cohort analysis utilized nine age-group classes for ages 40 to 84 years, eight time periods from 1970 to 2009, and 16 birth cohorts from 1886 to 1969.

Results

Age-adjusted IHD mortality rates for men and for women generally increased from 1970 to 1993 and from 1980 to 1999, respectively, decreasing thereafter for both sexes. IHD mortality rates for men and for women from Budapest were lower from 1991 and from 1970, respectively, than corresponding rates in non-capital counties, with the difference increasing after 1999. Age had a more significant influence on mortality rates for women than for men. The period effect increased from 1972 to 1982 and decreased thereafter for men, while the period effect decreased consistently for women from 1972 to 2007. The decline in period effect for both sexes was larger for individuals from the capital than for those from non-capital counties. The cohort effect for both sexes declined from birth years 1890 to 1965, with a steeper decline for individuals from the capital than for those from non-capital counties.

Conclusions

The findings indicate a need for programs in Hungary for IHD prevention, especially for non-capital counties.Key words: ischaemic heart disease, mortality, age-period-cohort, Hungary     

Changing patterns of ischaemic heart disease mortality in New Jersey 1968-1982, and the relationship with urbanization

Geographical variations in the declining rates of ischaemic heart disease (IHD) mortality may provide clues about various environmental risk factors responsible as a mass influence on the population IHD rate. The rate of IHD decline in 18 of 21 NJ counties was 2 to 45% less than the USA national rate of decline. The overall decline of IHD mortality in New Jersey (NJ) counties lagged significantly (p less than 0.05 to p less than 0.0003) behind the national trend. Age-adjusted mortality rate (AAMR) for IHD in NJ's 21 counties were 4% to 56% higher than the US rates. The IHD mortality rate of 14 of 21 NJ, counties and the entire state were significantly (p less than 0.005 to p less than 0.000001) above the US rate. Highly urbanized, industrialized, and densely populated NJ counties had the highest IHD rates. In these highly urbanized, industrialized and overcrowded NJ counties the AAMR for IHD was significantly higher and the IHD decline was significantly lower than that in the US. There was a significant (p less than 0.02 to p less than 0.00001) inverse association between annual per capita income and IHD rates. These data suggest that a high degree of urbanization, extensive industrialization, high population density and low socioeconomic status were acting as mass influences on the NJ population IHD rate.     

Patterns of infant mortality and cancer death in Alabama, USA

Aim  To use recent information of infant and cancer mortality in Alabama counties of the USA to test their relationships with social, economic, and environmental conditions at a large scale to identify potential public health issues. Subjects and methods  The data of infant mortality rates and cancer deaths in the recent years, biodiversity, including species number of plants, fishes, reptiles, and amphibians, roadless areas, metropolitan areas, river basins, African-American and minority populations, and per person income for all 67 Alabama counties were obtained and organized by geographic information system. The relationships between infant mortality rates and cancer deaths and social, economic, and environmental conditions at a large scale were analyzed. Results  Infant mortality was significantly higher in African-American and other minority populations than in white populations, but cancer mortality was higher in white populations than in African-American and minority populations. There was no significant difference in infant mortality rate between populations in the urban areas and the rural areas, but the mortality rate of cancers was significantly higher in the rural population than in the urban population. Mortality rates for cancers in wealthy counties were lower than in poorer counties. The incidences of infant and cancer mortality were lower in counties with higher biodiversity. The emergent spatial pattern suggests that the incidences of infant and cancer mortality were higher in the Sipsey/Warrior River Basin, Coosa/Tallapoosa River Basin, and Conecuh River Basins. Conclusion  This study indicates that ethnic disparities in infant and cancer mortality still exist in Alabama. This study also suggests that pattern analyses at larger scales can provide new insight for understanding public health.     

White infant mortality in Appalachian states, 1976-1980 and 1996-2000: changing patterns and persistent disparities

Purpose: Appalachian counties have historically had elevated infant mortality rates. Changes in infant mortality disparities over time in Appalachia are not well‐understood. This study explores spatial inequalities in white infant mortality rates over time in the 13 Appalachian states, comparing counties in Appalachia with non‐Appalachian counties. Methods: Data are analyzed for 1,100 counties in 13 Appalachian states that include 420 counties designated as Appalachian by the Appalachian Regional Commission. Area Resource File data for 1976‐1980 and 1996‐2000 provide county‐ and city‐level infant mortality rates, poverty rates, rural‐urban continuum codes, and numbers of physicians per 1,000 residents. Multiple regression analyses evaluate whether Appalachian counties are significantly associated with elevated white infant mortality in each time period, accounting for covariates. Findings: White infant mortality rates decreased substantially in all sub‐regions over the last 2 decades; however, disparities in infant mortality did not diminish in Appalachian counties compared to non‐Appalachian counties. After accounting for poverty, rural/urban status, and health care resources, Appalachian counties were significantly associated with comparatively higher infant mortality during the late 1970s but not in the late 1990s. At the more recent time point, higher poverty rates, residence in more rural areas, and lower physician density were associated with greater infant mortality risk. Conclusion: Appalachian counties continue to experience relatively elevated infant mortality rates. Poverty and rurality remain important dimensions of health service need in Appalachia.     

Clusters of cancer mortality in New Jersey municipalities; with special reference to chemical toxic waste disposal sites and per capita income

The state of New Jersey (NJ), USA, has been thought to have an unusually high cancer mortality rate; this assumption has been based on 1950-1969 mortality data for NJ counties. This study presents an analysis of mortality from major cancers for NJ municipalities during 1968-1977, and correlates cancer mortality rates with several potentially relevant variables. Age-adjusted mortality rates for 13 major cancer sites for 194 municipalities of 10 000 or more people in 21 NJ counties were compared with cancer mortality in the US. Municipality rates were correlated with: distribution of chemical toxic waste disposal sites (CTWDS); annual per capita income; the rates of low birth weight, birth defects and infant mortality of NJ municipalities. Clusters of cancer mortality were observed in 23 municipalities in 10 counties in which a total of 98 age-adjusted cancer death rates were at least 50% above the national rate, and each of these municipalities had at least two race-sex-specific cancers in which the observed number of cancer deaths was greater than the expected number of deaths at the p less than 0.0005 level. Of these 98 excessive cancer death rates, 72% involved the gastrointestinal tract. Most of the municipalities are located in the highly industrialized densely populated northeastern part of the State. Correlation analyses showed a consistent and significant (p less than 0.05) negative correlation between income and cancer mortality in 11 of 12 cancers studied. These analyses also showed a significant positive association between 8 of 12 cancers studied and CTWDS in one or more subgroup populations and lesser associations with birth defects, low birth weight and infant mortality.     

Gastrointestinal cancer mortality in New Jersey counties, and the relationship with environmental variables

The State of New Jersey (NJ) USA has been thought to have an unusually high cancer mortality rate; this assumption has been based on 1950-1969 mortality data for its 21 counties. This paper presents an analysis of gastrointestinal (GI) cancer mortality rates in New Jersey counties during 1968-1977, a comparison with the 1950-1969 rates, and associations between current GI cancer mortality rates and selected environmental variables. Age-adjusted mortality rates for GI cancers were calculated for the 21 NJ counties during the period 1968-1977, and were compared with the period 1950-1969, with the Surveillance, Epidemiology and End Results (SEER) survey and with cancer mortality in the US, 1973-1977. The county rates were also correlated with: the distribution of chemical toxic waste disposal sites; annual per capita income; the rates of low birth weight, birth defects, and infant mortality; chemical industry distribution; percentage of the population employed in chemical industries; the density of population; and the urbanization index for each of the counties. Some of the major findings are: Age-adjusted GI cancer mortality rates (all sites combined) were higher than national rates in 20 of 21 NJ counties. In comparison with national trends, NJ stomach cancer rates have declined less, oesophageal cancer rates have declined more, and pancreatic cancer mortality rates have followed similar patterns. Cancer mortality rates in NJ during the period 1968-1977 significantly (p less than 0.0001) exceeded national rates for cancer of the oesophagus (white male, non-white male), stomach (men and women), colon (white male, white female, non-white female), and rectum (whites only). In 18 of the 21 NJ counties, the observed number of cancer deaths for at least one GI cancer site was significantly greater than expected at the 0.0001 level for at least one population subgroup. Among white men, a significant (p less than 0.0001) excess of observed over expected cancer deaths was observed for three or more GI cancer sites in seven counties. The environmental variables that were most frequently associated with GI cancer mortality rates (except pancreatic cancer) were degree of urbanization, population density, and chemical toxic waste disposal sites. Some of the implications of the study findings are discussed and recommendations made for future investigations.     

Trends in mortality due to cardiovascular diseases in Andalusia, Spain (1975-2004)

BACKGROUND: Cardiovascular diseases are ranked among the leading causes of death in the industrialized countries. This study is aimed at ascertaining the mortality trends by ischemic heart disease (IHD) and cerebrovascular diseases (CVD) in Andalusia within the 1975-2004 period. METHOD: Based on the official IHD and CVD death statistics and the related populations, the gross rates (GR) and age-adjusted rates (TS) and the Potential Years of Life Lost (PYLL) were calculated. To quantify the trends and their change points, a joinpoint regression analysis was made. RESULTS: The number of IHD deaths for females rose from 2,086 deaths in 1975 to 3,336 in 2004, the TS having dropped from 74.29 to 50.94 deaths/100,000 females, the PYLL having dropped from 173.65 years to 90.56 years/100,000 females. The number of deaths for males rose from 2,854 deaths in 1975 to 4,085 in 2004, the TS having dropped from 147, 67 to 104.96 deaths /100,000 males. The PYLL showed a like behaviour from the first to the last year of the series, showing values of 716.46 and 460.04 years / 100,000 males. For the IHD in females, the number of deaths in absolute numbers dropped from 4,712 to 4,221, the TS having dropped from 166.00 to 62.08 deaths in females, and the PYLL from 338.08 to 87.63 years / 100,000 females. For males, the number of deaths dropped from 3,714 to 2,951, the TS from 206.88 deaths /100,000 males in 1975 to 76.12 /100,000 males in 2004, and the PYLL dropping from 533.12 to 182.38 years / 100,000 males. CONCLUSIONS: The trend in mortality due to IHD was not constant either among females or males, although it has always been a downward trend, the drop being statistically significant. The drop in the CVD has been such a major one that both the absolute numbers and the gross rates are lower for the most recent years that the first years in the series studied despite the aging of Andalusias population.     

Mortality from cardiovascular diseases in three Brazilian states from 1980 through 2002]

OBJECTIVE: To evaluate and compare adult mortality from diseases of the circulatory system (CDs), especially ischemic heart disease (IHD) and cerebrovascular disease (CVD), from 1980 through 2002 in the Brazilian states of Rio de Janeiro, Rio Grande do Sul, and S?o Paulo and their capital cities (respectively Rio de Janeiro, Porto Alegre, and S?o Paulo), taking into account the impact of deaths due to ill-defined causes on mortality rates. METHOD: We estimated mortality rates (crude and adjusted by age and sex) from CDs overall and from IHD and CVD among individuals aged 20 years or older. These rates were weighted with a portion of the deaths from ill-defined or unknown causes, in the same proportion as deaths from CDs, IHD, and CVD in relation to deaths overall, excluding deaths from ill-defined causes. Using linear regression models, we also estimated the mean values of and annual differences in the weighted adjusted mortality rates. The reference population was that of the state of Rio de Janeiro in 2000. RESULTS: The annual decline in the weighted adjusted mortality rates from CDs ranged from -13.1 per 100,000 individuals in the state of Rio de Janeiro to -8.7 per 100,000 in the city of S?o Paulo. For IHD, the annual declines were greatest in the city of Rio de Janeiro (-5.0 per 100,000) and the state of Rio de Janeiro (-4.5 per 100,000), and smallest in the state of Rio Grande do Sul (-2.8 per 100,000) and the city of S?o Paulo (-2.7 per 100,000). With CVD, the range that was found extended from -6.5 per 100,000 in the state of Rio de Janeiro to -2.9 per 100,000 in the city of Porto Alegre. CONCLUSION: The decreases in weighted adjusted mortality rates from CDs, IHD, and CVD occurred after 1980, so it is unlikely that the declines resulted from controlling risk factors or from the practice of myocardial revascularization. The decreases might be related to a period of strong economic development preceding the declines, which translated into improved living conditions and reduced exposure to infections in the perinatal period and childhood.     

Reducing infant mortality in rural America: evaluation of the Rural Infant Care Program.

The Rural Infant Care Program (RICP), initiated in 1979, was developed to improve perinatal health care in ten rural sites with histories of high infant mortality rates. Time-series regression models indicate that neonatal mortality rates were reduced, following program initiation, by 2.6 per 1,000 live births (p = .0002); black neonatal mortality rates were reduced by an estimated 4.5 per 1,000 (p = .0004). Three sets of comparison areas exhibited no significant changes in rates. Postneonatal mortality rates did not increase in the target areas following initiation of RICP, indicating that deaths were not merely being postponed. Nine of ten individual sites showed reductions in infant mortality following program initiation. Birthweight-specific mortality data indicated that the decline was due mainly to reductions in neonatal mortality among low-birthweight infants. No reductions in the incidence of low birthweight were observed in the target areas. Substantial gaps in the delivery of prenatal care remained due to the continuing poverty of the population and the resultant lack of financial coverage for health services. We conclude that improved perinatal medical care can reduce infant mortality in poor rural areas to average levels experienced in the United States, and that the high rates still observed in some rural counties are unnecessary.     

Early increases in ischaemic heart disease mortality dissociated from and later changes associated with respiratory mortality after cold weather in south east England.

STUDY OBJECTIVE: To identify the time courses and magnitude of ischaemic heart (IHD), respiratory (RES), and all cause mortality associated with common 20-30 day patterns of cold weather in order to assess links between cold exposure and mortality. DESIGN: Daily temperatures and daily mortality on successive days before and after a reference day were regressed on the temperature of the reference day using high pass filtered data in which changes with a cycle length < 80 days were unaffected (< 2%), but slower cyclical changes and trends were partly or completely suppressed. This provided the short term patterns of both temperature and mortality associated with a one day displacement of temperature. The results were compared with simple regressions of unfiltered mortality on temperature at successive delays. STUDY POPULATION AND SETTING: Population of south east England, including London, over 50 years of age from 1976-92. MAIN RESULTS: Colder than average days in the linear range 15 to 0 degrees C were associated with a "run up" of cold weather for 10-15 days beforehand and a "run down" for 10-15 days afterwards. The increases in deaths were maximal at 3 days after the peak in cold for IHD, at 12 days for RES, and at 3 days for all cause mortality. The increase lasted approximately 40 days after the peak in cold. RES deaths were significantly delayed compared with IHD deaths. Excess deaths per million associated with these short term temperature displacements were 7.3 for IHD, 5.8 for RES, and 24.7 for all cause, per one day fall of 1 degree C. These were greater by 52% for IHD, 17% for RES, and 37% for all cause mortality than the overall increases in daily mortality per degree C fall, at optimal delays, indicated by regressions using unfiltered data. Similar analyses of data at 0 to -6.7 degrees C showed an immediate rise in IHD mortality after cold, followed by a fall in both IHD and RES mortality rates which peaked 17 and 20 days respectively after a peak in cold. CONCLUSION: Twenty to 30 day patterns of cold weather below 15 degrees C were followed:(1) rapidly by IHD deaths, consistent with known thrombogenic and reflex consequences of personal cold exposure; and (2) by delayed increases in RES and associated IHD deaths in the range 0 to 15 degrees C, which were reversed for a few degrees below 0 degree C, and were probably multifactorial in cause. These patterns provide evidence that personal exposure to cold has a large role in the excess mortality of winter.     

Importance of the first day death rate in infant mortality

The conventional partition of infant mortality into neonatal and postneonatal deaths, with the 28th day postpartum as the dividing line, has lost much of its epidemiological rationale in countries with low infant death rates. Infant deaths are concentrated increasingly at the start of the neonatal period: one out of three infant deaths in the United States occurs during the first 24 hours. Circumstances of early neonatal deaths differ considerably from those of later neonatal deaths. Failure to monitor separately early and late neonatal mortality can compromise the recognition of distinct epidemiological patterns. Racial disparities in the US tend to be larger for first day deaths than for any other infant deaths. Total US infant mortality declined rapidly in the 1950s and 1960s but first day deaths rose at a steady pace. Surveillance of infant mortality, whether on the national or the community level, should encompass first day, first month and first year death rates.     

Are geographical differences in cardiovascular mortality due to morbidity differences or to methodological differences? The project "myocardial infarction in Mid-Sweden".

Geographical variations in cardiovascular mortality have been reported from Mid-Sweden. IHD mortality for men aged 45-64 was 60% higher in the western part than in the east. Mortality from stroke for men aged 45-74 was 73% higher on the west. Similar differences were found for women. One possible explanation could be that there are no incidence differences but that the mortality differences are due to different survival rates or to differences certifying the cause of death. These two possible explanations were tested in this study. Data for all patients hospitalised during the 10-year period 1972-1981 for myocardial infarction or stroke in a high mortality area, the County of V?rmland in the west, and a low mortality area, the County of Uppsala in the east, were collected. In addition, a substudy was performed where the basis for the death certificate diagnosis was studied. The western area generally had a higher case fatality rate than the eastern. However, a larger proportion of the deaths the eastern area, occurred outside hospital, so that the net effect would be that the differences found were not large enough to explain the mortality differences. The autopsy rate in the western part was lower than in the east but since a larger proportion of the deaths occurred in hospital the rank order for IHD and stroke mortality between east and west was the same whether all IHD or stroke deaths were counted or only those considered the most well documented.     

Path analysis of socioeconomic correlates of county infant mortality rates.

Relationships between selected socioeconomic characteristics of counties and infant mortality rates are examined. There are two research objectives: to determine the extent to which low family income, low education, sound housing, and the percentage of blacks "directly" and "jointly" relate to neonatal and postneonatal mortality rates; and to determine the degree to which a zero-order correlation between a given socioeconomic measure and general infant mortality is transmitted by neonatal and postneonatal mortality rates, respectively. Data corresponding to 2237 counties in the United States are analyzed by path analysis. Results show that the percentage of blacks and low education are two variables which have appreciable direct effects on both components of infant mortality. These two factors are also responsible in large measure for gross associations between low family income, sound housing, and rates of infant loss. On the basis of this study it is estimated that approximately two-thirds of the zero-order correlation between a given county measure of socioeconomic status and infant mortality occurs through the postneonatal component. Implications of these findings are discussed.     

Why are Thai official perinatal and infant mortality rates so low?

The accuracy of perinatal and infant mortality rates in most developing countries is questionable. We measured perinatal and infant mortality rates in a rural district of Thailand and compared them with the official statistics to assess accuracy. All births and infant deaths in a rural district of Thailand over a one-year period were surveyed. The corresponding official statistics were also collected. The mothers or the relatives of all stillbirths and infant deaths were interviewed about the registration of the stillbirths or infant deaths. The surveyed perinatal and infant mortality rates were 22.0 and 23.1 respectively. The under-registration of stillbirths was 100% and for infant deaths 45%. All the non-registered infant deaths were in situations in which the infant died before the registration of birth. These results document the degree and nature of under-reporting of perinatal and infant mortality in rural Thailand.     

Respiratory organs cancer mortality in New Jersey counties and the relationship with selected demographic and environmental variables

The state of New Jersey (N.J.) has been thought to have an unusually high overall cancer mortality rate; this assumption has been based on national 1950–1969 mortality data for N.J. counties. This study presents an analysis of more recent rates of respiratory cancer mortality in 21 N.J. counties during 1968–1977, a comparison with the 1950–1969 rates, and associations between current respiratory cancer mortality rates and selected demographic and environmental variables. Age-adjusted mortality rates for cancer of respiratory organs were calculated for the N.J. counties during the period 1968–1977 and compared with the period 1950–1969, with the Surveillance, Epidemiology, and End Results (SEER) survey, and with cancer mortality in the United States, 1973–1977. The county rates were also correlated with chemical toxic-waste disposal sites (CTWDS), annual per capita income, percentage of the population employed in chemical industries, the density of population, and the urbanization index of each of 21 N.J. counties. The lung, bronchus, trachea, and pleura cancer mortality rates among white and nonwhite males and females in N.J. were substantially higher than the national rates during the period 1950–1969. In more recent years, the increases in U.S. mortality rates for lung, bronchus, trachea, and pleura cancers were significantly greater (P < 0.01) than those found in most of the 21 N.J. counties. As a consequence, the national rates are now more comparable to N.J. rates. Although the gaps between N.J. and the United States in these rates have narrowed, the observed number of laryngeal and lung cancer deaths remained significantly higher (P < 0.01 to P < 0.0001) than expected cancer deaths, based on U.S. rates, among one or more subgroup populations (white and nonwhite males and females) in several N.J. counties. Among white men in Middlesex, Camden, Burlington, and Ocean counties, the observed number of deaths for lung cancer was found to be significantly (P < 0.0001) greater than the expected number of deaths. In Hudson county observed deaths from both laryngeal and lung cancer among white men were significantly greater than the expected number of deaths from these cancers (P < 0.0001). Statistically significant and positive correlations were found between laryngeal cancer mortality and CTWDS, urbanization index, and population density. Lung cancer mortality also correlated significantly with CTWDS in N.J. Both larynx and lung cancer mortality showed significant and consistent negative correlations with annual per capita-income in N.J. Some of the implications of the study findings are discussed and recommendations made for future investigations.     

Does the occupational structure of the Hunter Region explain the high rates of ischaemic heart disease among its men?

To compare rates of ischaemic heart disease (IHD) among men in occupation groups defined by the new Australian Standard Classification of Occupations (ASCO) and to investigate whether their high mortality rates from IHD in the Hunter Region of New South Wales (NSW) could be explained by its occupational structure, we used official death records and data from the World Health Organization MONICA Project conducted in Newcastle. The study population consisted of men aged 25 to 64 years in NSW and in the Hunter Region for whom occupational information was available. For deaths from IHD between 1984 and 1988 in NSW, indirectly standardised mortality and morbidity ratios (SMRs) were: significantly low for professionals, 66 (95% confidence interval (CI) 60-71) and managers and administrators, 79 (95% CI 74-83); intermediate for paraprofessionals (92), clerks (94) and salesmen and personal service workers (97); and significantly high for tradesmen, 113 (95% CI 107-118), labourers and related workers, 118 (95% CI 113-124) and plant and machine operators and drivers, 125 (95% CI 118-133). Broadly similar patterns were found for IHD deaths and for fatal and nonfatal myocardial infarction in the Hunter Region. When occupation- and age-specific mortality rates from IHD were used to calculate SMRs for the Hunter Region, SMRs for all ASCO groups except paraprofessionals were over 100. Mortality rates for occupational groups classified by ASCO were consistent with well-established differences associated with socioeconomic status.(ABSTRACT TRUNCATED AT 250 WORDS)     

Trends in chronic disease mortality in the Northern Territory Aboriginal population, 1997‐2004: using underlying and multiple causes of death

Objective: To assess trends in chronic disease mortality in the Aboriginal population of the Northern Territory (NT), using both underlying and multiple causes of death. Method: Death registration data from 1997 to 2004, were used for the analysis of deaths from five chronic diseases; ischaemic heart disease (IHD), diabetes, chronic obstructive pulmonary disease (COPD), renal failure and stroke. Negative binomial regression models were used to estimate the average annual change in mortality rates for each of the five diseases. Chi squared tests were conducted to determine associations between the five diseases. Results: The five chronic diseases contributed to 49.3% of all Aboriginal deaths in the NT. The mortality rate ratio of NT Aboriginal to all Australian death rates from each of the diseases ranged from 4.3 to 13.0, with the lowest rate ratio for stroke and highest for diabetes. There were significant statistical associations between IHD, diabetes, renal failure and stroke. The mortality rates for diabetes, COPD and stroke declined at estimated annual rates for NT Aboriginal males of 3.6%, 1.0% and 11.7% and for Aboriginal females by 3.5%, 6.1% and 7.1% respectively. There were increases in mortality rates for Aboriginal males and females for IHD and a mixed result for renal failure. Conclusion: NT Aboriginal people experience high chronic disease mortality, however, mortality rates appear to be declining for diabetes, COPD and stroke. The impact of chronic disease on mortality is greater than previously reported by using a single underlying cause of death. The results highlight the importance of integrated chronic disease interventions.     

Are very low birthweight births among American Indians and Alaska Natives underregistered?

BACKGROUND: International infant mortality rates vary widely. This variation has been attributed to many factors, including differential reporting. In the US, American Indians and Alaska Natives (AI/AN), who generally have low socioeconomic status, have a low neonatal mortality rate. One possible explanation is underregistration of very low birthweight (VLBW, < 1,500 g) births. We hypothesized that underregistration may occur disproportionately among AI/AN residing on or near reservations (areas controlled by an American Indian group). We estimated infant mortality in these areas. METHODS: Linked birth-infant death files for 1989-1991 were used to compare VLBW and neonatal mortality among AI/AN infants in counties with reservations with those in non-reservation counties. The VLBW rates for non-reservation counties were applied to the reservation risk distribution to calculate directly adjusted VLBW and neonatal mortality rates for reservation counties. This method assumes that greater registration in non-reservation counties yields a more accurate estimate of the relationship between risk factors and outcomes. RESULTS: Despite a higher prevalence in reservation counties of risk factors, the reported VLBW rate was 0.84% in reservation and 1.17% in non-reservation counties. The neonatal mortality rate was 5.4 per 1,000 in reservation counties and 6.0 in non-reservation counties. Direct adjustment yielded a VLBW rate of 1.28% (95% CI: 1.14-1.39) and a neonatal mortality rate of 6.7-9.8 per 1,000 in reservation counties. CONCLUSIONS: Reported neonatal mortality among AI/AN may understate the true rate due to underregistration of VLBW births. Direct adjustment may be useful in estimating infant mortality rates for populations with incomplete vital registration.     

四川省2001-2009年婴儿死亡率变化趋势及死因分析

目的 了解2001-2009年四川省婴儿年龄别和主要死因别死亡率的变化趋势.方法 采用四川省5岁以下儿童死亡监测收集的2001-2009年监测点儿童死亡资料,计算城乡新生儿、婴儿死亡率及婴儿死因别死亡率.结果 2009年四川省新生儿、婴儿死亡率分别为7.6‰和12.1‰,较2001年(18.6‰和25.5‰)分别下降了...