Effect of statins on the mortality of patients with ischaemic heart disease: population based cohort study with nested case-control analysis

OBJECTIVE

To measure the effect of statins on mortality for community based patients with ischaemic heart disease and determine whether the likely benefits are similar for women, the elderly, and patients with diabetes.

DESIGN

Open prospective cohort study with nested case-control analysis.

SETTING

1.18 million patients registered with 89 practices spread across 23 strategic health authority areas within the UK. All practices had a minimum of eight years of longitudinal data and were contributing to the UK QRESEARCH database.

SUBJECTS

All patients with a first diagnosis of ischaemic heart disease between January 1996 and December 2003.

OUTCOMES

Adjusted hazard ratio with 95% confidence intervals (CIs) for all cause mortality (cohort analysis) and odds ratio (OR) with 95% CI (case-control analysis) for current use of statins. Adjustments were made for current use of aspirin, beta blockers, and angiotensin converting enzyme inhibitors, co-morbidity (myocardial infarction, diabetes, hypertension, congestive cardiac failure), smoking, body mass index, and quintile of deprivation.

RESULTS

13,029 patients had a first diagnosis of ischaemic heart disease in the study period giving an incidence rate of 3.38/1000 person years. 2266 patients with ischaemic heart disease died during the 43,460 person years of observation giving an overall mortality rate of 52.1/1000 person years (95% CI 50.0 to 54.3). In the case-control analysis, patients taking statins had a 39% lower risk of death than did patients not taking statins (adjusted OR 0.61, 95% CI 0.52 to 0.72) after use of other medication, co-morbidity, smoking, body mass index, and deprivation were taken into account. The benefits found in this study compared favourably with those found in the randomised controlled trials, although the current study population is at higher overall risk. The benefits extend to women, patients with diabetes, and the elderly and can be seen within two years of treatment. Longer duration of usage was associated with lower OR for risk of death with a 19% reduction in risk of death with each additional year of treatment (adjusted OR 0.81, 95% CI 0.77 to 0.86 per year). Mortality was similarly reduced among patients prescribed atorvastatin (adjusted OR 0.62, 95% CI 0.48 to 0.79) and simvastatin (adjusted OR 0.62, 95% CI 0.50 to 0.76).

CONCLUSIONS

The benefits of statins found in randomised controlled trials extend to unselected community based patients. The benefits can be seen within the first two years of treatment and continue to accrue over time. Since patients in the community are likely to be at higher risk than those in trials, the potential benefits from statins are likely to be greater than expected.

Using cohort studies to estimate mortality among injecting drug users that is not attributable to AIDS

BACKGROUND

Injecting drug use (IDU) and associated mortality appear to be increasing in many parts of the world. IDU is an important factor in HIV transmission. In estimating AIDS mortality attributable to IDU, it is important to take account of premature mortality rates from other causes to ensure that AIDS related mortality among injecting drug users (IDUs) is not overestimated. The current review provides estimates of the excess non-AIDS mortality among IDUs.

METHOD

Searches were conducted with Medline, PsycINFO, and the Web of Science. The authors also searched reference lists of identified papers and an earlier literature review by English et al (1995). Crude mortality rates (CMRs) were derived from data on the number of deaths, period of follow up, and number of participants. In estimating the all-cause mortality, two rates were calculated: one that included all cohort studies identified in the search, and one that only included studies that reported on AIDS deaths in their cohort. This provided lower and upper mortality rates, respectively.

RESULTS

The current paper derived weighted mortality rates based upon cohort studies that included 179 885 participants, 1,219,422 person-years of observation, and 16,593 deaths. The weighted crude AIDS mortality rate from studies that reported AIDS deaths was approximately 0.78% per annum. The median estimated non-AIDS mortality rate was 1.08% per annum.

CONCLUSIONS

Illicit drug users have a greatly increased risk of premature death and mortality due to AIDS forms a significant part of that increased risk; it is, however, only part of that risk. Future work needs to examine mortality rates among IDUs in developing countries, and collect data on the relation between HIV and increased mortality due to all causes among this group.

Child mortality due to suffocation in Europe (1980-1995): a review of official data

This report outlines the current status of the official statistical data available concerning mortality rates for suffocation in children <15 years of age, stratified according to sex and country in Europe, in the years 1980-1995. The data source is the WHO Mortality Database, which comprises deaths registered in national vital registration systems, with underlying cause of death as coded by the relevant national authority. To assess the impact of the problem of suffocation, the total potential years of life lost have been calculated. In addition, for Italy, and for the years 1999-2000, data related to deaths and hospitalizations for foreign body in the pharynx and larynx are presented. In Italy, in the years 1999-2000, the ratio between the number of hospitalizations and the mortality rates is approximately one death every 10 hospitalizations (x 100,000). The European mortality rate exceeds nearly one death per 100,000 persons. No evidence of any geographical pattern or cyclic trend emerged from the analysis of this official data.

Trends in childhood injury mortality in Canada, 1979-2002

OBJECTIVE

To examine national trends in mortality rates for injuries among Canadian children younger than 15 years in 1979-2002.

METHODS

Data on injury deaths were obtained from the Canadian Vital Statistics system at Statistics Canada. Injuries were classified using the codes for external cause of injury and poisoning (E-codes) by intent and by mechanism. Mortality rates were age adjusted to the 1990 world standard population. Negative binomial regression was used to estimate the secular trends.

RESULTS

Annual mortality rates for total and unintentional injuries declined substantially (from 23.8 and 21.7 in 1979 to 7.2 and 5.8 in 2002, respectively), whereas suicide deaths among children aged 10-14 showed an increasing trend. All Canadian provinces and territories showed a decreasing trend in mortality rates of total injuries. Motor vehicle related injuries were the most common cause of injury deaths (accounted for an average of 36.4% of total injury deaths), followed by suffocation (14.3%), drowning (13.5%), and burning (11.1%); however, suffocation was the leading cause for infants. The number of potential years of life lost due to injury before age 75 decreased from 89 343 in 1979 to 27 948 in 2002 for children aged 0-14 years.

CONCLUSIONS

During the period 1979-2002, there were dramatic decreases in childhood mortality for total injuries and unintentional injuries as well as various degrees of reduction for all causes of injury except suffocation in children aged 10-14 years and drowning in infants. The reason for the reduction in injury mortality might be multifactoral.

The burden of malaria mortality among African children in the year 2000

BACKGROUND

Although malaria is a leading cause of child deaths, few well-documented estimates of its direct and indirect burden exist. Our objective was to estimate the number of deaths directly attributable to malaria among children <5 years old in sub-Saharan Africa for the year 2000.

METHODS

We divided the population into six sub-populations and, using results of studies identified in a literature review, estimated a malaria mortality rate for each sub-population. Malaria deaths were estimated by multiplying each sub-population by its corresponding rate. Sensitivity analyses were performed to assess the impact of varying key assumptions.

RESULTS

The literature review identified 31 studies from 14 countries in middle Africa and 17 studies and reports from four countries in southern Africa. In 2000, we estimated that approximately 100 million children lived in areas where malaria transmission occurs and that 803 620 (precision estimate: 705 821-901 418) children died from the direct effects of malaria. For all of sub-Saharan Africa, including populations not exposed to malaria, malaria accounted for 18.0% (precision estimate: 15.8-20.2%) of child deaths. These estimates were sensitive to extreme assumptions about the causes of deaths with no known cause.

CONCLUSIONS

These estimates, based on the best available data and methods, clearly demonstrate malaria's enormous mortality burden. We emphasize that these estimates are an approximation with many limitations and that the estimates do not account for malaria's large indirect burden. We describe information needs that, if filled, might improve the validity of future estimates.

Influence of orthostatic hypotension on mortality among patients discharged from an acute geriatric ward

BACKGROUND

Orthostatic hypotension (OH) is a common finding among older patients. The impact of OH on mortality is unknown.

OBJECTIVE

To study the long-term effect of OH on total and cardiovascular mortality.

PATIENTS AND METHODS

A total of 471 inpatients (227 males and 244 females), with a mean age of 81.5 years who were hospitalized in an acute geriatric ward between the years 1999 and 2000 were included in the study. Orthostatic tests were performed 3 times during the day on all patients near the time of discharge. Orthostatic hypotension was defined as a fall of at least 20 mmHg in systolic blood pressure (BP) and/or 10 mmHg in diastolic BP upon assuming an upright posture at least twice during the day. Patients were followed until August 31, 2004. Mortality data were taken from death certificates.

RESULTS

One hundred and sixty-one patients (34.2%) experienced OH at least twice. Orthostatic hypotension had no effect on all cause and cause specific mortality. Over a follow-up of 3.47+/-1.87 years 249 patients (52.8%) had died 83 of whom (33.3%) had OH. Age-adjusted mortality rates in those with and without OH were 13.4 and 15.7 per 100 person-years, respectively. Cox proportional hazards model analysis demonstrated that male gender, age, diabetes mellitus, and congestive heart failure increased and high body mass index decreased total mortality.

CONCLUSIONS

Orthostatic hypotension is relatively common in elderly patients discharged from acute geriatric wards, but has no impact on vascular and nonvascular mortality.

Prediction of in-hospital mortality and length of stay using an early warning scoring system: clinical audit

This aim of this study was to assess the impact of the introduction of a standardised early warning scoring system (SEWS) on physiological observations and patient outcomes in unselected acute admissions at point of entry to care. A sequential clinical audit was performed on 848 patients admitted to a combined medical and surgical assessment unit during two separate 11-day periods. Physiological parameters (respiratory rate, oxygen saturation, temperature, blood pressure, heart rate, and conscious level), in-hospital mortality, length of stay, transfer to critical care and staff satisfaction were documented. Documentation of these physiological parameters improved (P<0.001-0.005) with the exception of oxygen saturation (P=0.069). The admission early warning score correlated both with in-hospital mortality (P<0.001) and length of stay (P=0.001). Following the introduction of the scoring system, inpatient mortality decreased (P=0.046). Staff responding to a questionnaire indicated that the scoring system increased awareness of illness severity (80%) and prompted earlier interventions (60%). A standardised early warning scoring system improves documentation of physiological parameters, correlates with in-hospital mortality, and helps predict length of stay.

Successful aging: measuring the years lived with functional loss

Current research of risk factors potentially associated with successful aging faces the difficulty of taking into consideration two distinct outcome measures: survival and functioning. Previous studies either used successful aging measures restricted to survivors or presented more than one outcome measure to handle the dual outcome. This article illustrates the utility of health expectancy measures, based on life tables, to integrate the effects of survival and functioning across all ages. It is shown that three hypothetical successful aging strategies, considered equally successful according to the traditional measures restricted to survivors, are associated with vastly different changes in the years lived with and without disability. Furthermore, the intervention considered most successful when considering multiple successful aging measures, was associated with the largest increase in the time lived with disability. It is recommended that research on successful aging should be based on summary measures of population health that reflect both survival and functioning throughout life. These will provide more relevant information than is currently available for individuals and societies to evaluate and choose between successful aging strategies.

Impact of specialist care on clinical outcomes for medical emergencies

General hospitals have commonly involved a wide range of medical specialists in the care of unselected medical emergency admissions. In 1999, the Royal Liverpool University Hospital, a 915-bed hospital with a busy emergency service, changed its system of care for medical emergencies to allow early placement of admitted patients under the care of the most appropriate specialist team, with interim care provided by specialist acute physicians on an acute medicine unit - a system we have termed 'specialty triage'. Here we describe a retrospective study in which all 133,509 emergency medical admissions from February 1995 to January 2003 were analysed by time-series analysis with correction for the underlying downward trend from 1995 to 2003. This showed that the implementation of specialty triage in May 1999 was associated with a subsequent additional reduction in the mortality of the under-65 age group by 0.64% (95% CI 0.11 to 1.17%; P=0.021) from the 2.4% mortality rate prior to specialty triage, equivalent to approximately 51 fewer deaths per year. No significant effect was seen for those over 65 or all age groups together when corrected for the underlying trend. Length of stay and readmission rates showed a consistent downward trend that was not significantly affected by specialty triage. The data suggest that appropriate specialist management improves outcomes for medical emergencies, particularly amongst younger patients.

Outcome of extreme prematurity: as information increases so do the dilemmas

Application of technology in neonatal intensive care has been very successful in reducing mortality, particularly in extremely low birthweight infants. As survival has improved, the need for accurate studies of long term outcome has increased. This need has been met by studies that are larger, more inclusive, and address a wider variety of later outcomes. Rather than a comprehensive quantitative review of these studies, this article uses a smaller number of studies that focus on infants of borderline viability, to illustrate current dilemmas and challenges in interpretation, and the actions, both individual and societal, that may be prompted by these interpretations.

Temperature and summer mortality: geographical and temporal variations in four Italian cities

STUDY OBJECTIVE

To investigate geographical and temporal variations in the temperature-mortality relation.

DESIGN

The relation between mortality and maximum apparent temperature (Tappmax) in 2003, 2004, and a previous reference period was explored by using segmented regression and generalised additive models.

SETTING

Four Italian cities (Bologna, Milano, Roma, and Torino), included in a national network of prevention programmes and heat health watch warning systems (HHWWS) were considered.

PARTICIPANTS

Daily mortality counts of the resident population dying in each city during summer (June to September).

MAIN RESULTS

The impact of Tappmax on mortality differed between cities and varied in the three periods analysed. The geographical heterogeneity of the J shaped relation was seen in the reference period with Tappmax thresholds ranging from 28 degrees C in Torino to 32 degrees C in Milano and Roma. In all cities, the percentage variation in mortality was greatest in 2003. In Torino and Roma a significant increase was seen also at lower Tappmax values that are usually not associated to an increase in mortality (26-28 degrees C). In summer 2004 the exposure levels were similar to the reference period; only in Torino the effect of Tappmax on mortality remained relevant even if reduced compared with 2003, while in Bologna no statistically significant effect was seen for any temperature range.

CONCLUSIONS

The observed heterogeneous reduction in the impact of temperature on mortality from 2003 to 2004 may be partly explained by the lower levels of exposure. Changes in the ability of individuals and communities to adjust to high temperatures as a consequence of the implementation of public health interventions, based on HHWWS, characterised by a diverse effectiveness, may also have played an important part.

Crohn's disease: increased mortality 10 years after diagnosis in a Europe-wide population based cohort

BACKGROUND

No previous correlation between phenotype at diagnosis of Crohn's disease (CD) and mortality has been performed. We assessed the predictive value of phenotype at diagnosis on overall and disease related mortality in a European cohort of CD patients.

METHODS

Overall and disease related mortality were recorded 10 years after diagnosis in a prospectively assembled, uniformly diagnosed European population based inception cohort of 380 CD patients diagnosed between 1991 and 1993. Standardised mortality ratios (SMRs) were calculated for geographic and phenotypic subgroups at diagnosis.

RESULTS

Thirty seven deaths were observed in the entire cohort whereas 21.5 deaths were expected (SMR 1.85 (95% CI 1.30-2.55)). Mortality risk was significantly increased in both females (SMR 1.93 (95% CI 1.10-3.14)) and males (SMR 1.79 (95% CI 1.11-2.73)). Patients from northern European centres had a significant overall increased mortality risk (SMR 2.04 (95% CI 1.32-3.01)) whereas a tendency towards increased overall mortality risk was also observed in the south (SMR 1.55 (95% CI 0.80-2.70)). Mortality risk was increased in patients with colonic disease location and with inflammatory disease behaviour at diagnosis. Mortality risk was also increased in the age group above 40 years at diagnosis for both total and CD related causes. Excess mortality was mainly due to gastrointestinal causes that were related to CD.

CONCLUSIONS

This European multinational population based study revealed an increased overall mortality risk in CD patients 10 years after diagnosis, and age above 40 years at diagnosis was found to be the sole factor associated with increased mortality risk.

Interleukin-10 polymorphism in position -1082 and acute respiratory distress syndrome

The GG genotype of the interleukin (IL)-10 promoter polymorphism in position -1082 (-1082GG) has been associated with increased IL-10 production. The current authors hypothesised that the -1082GG genotype is associated with the development of, and outcomes in, acute respiratory distress syndrome (ARDS). A nested case-control study was conducted in 211 Caucasian cases of ARDS and 429 controls who were admitted to an intensive care unit with sepsis, trauma, aspiration or massive transfusions. Cases were followed for organ failure and 60-day mortality. The -1082GG genotype was associated with the development of ARDS, but only in the presence of a significant interaction between the -1082GG genotype and age. Among patients with ARDS, the -1082GG genotype was associated with decreased severity of illness on admission, lower daily organ dysfunction scores and lower 60-day mortality. In conclusion, the high interleukin-10-producing -1082GG genotype may be associated with variable odds for acute respiratory distress syndrome development depending on age. Among those with acute respiratory distress syndrome, the -1082GG genotype is associated with lower mortality and organ failure. Further studies are needed to confirm these findings.

Crohn's disease: why the disparity in mortality?

There has been no significant decrease in mortality in patients with Crohn's disease over the last several decades

Complications and mortality of single versus dual chamber implantable cardioverter defibrillators

BACKGROUND

The implantable cardioverter defibrillators (ICDs) are increasingly being used as a treatment modality for life threatening tachyarrhythmia. The purpose of this study was to compare the frequency of complications and mortality between single-chamber and dual-chamber ICD implantation in Shahid Rajaie cardiovascular center.

METHODS AND RESULTS

Between January 2000 and December 2004, 234 patients received ICD by a percutaneous transvenous approach and were followed for 33 +/- 23 months. The cumulative incidence of complications was 9.4% over the follow-up period. There was no significant difference in overall complication rate between single chamber (VR) and dual chamber (DR) ICD groups in the follow-up period (P= 0.11). The risk of complications did not have any statistically significant difference in secondary versus primary prevention groups (P=0.06). The complications were not associated with the severity of left ventricular systolic dysfunction (P=0.16). The frequency of lead-related complications was higher in dual chamber ICDs in comparison with single chamber ICDs (P=0.02). There was no significant difference in mortality between different sex groups (P=0.37), different indications for ICD implantation (P=0.43) or between VR and DR ICD groups (P= 0.55). Predictors of mortality were NYHA class III or more (P<0.001), age >65 years (P=0.011) and LVEF<30% (P<0.001). The mortality in patients with CAD and DCM were significantly higher than those with other structural heart diseases (P=0.001).

CONCLUSION

Close monitoring of patients during the first 2 month after ICD implantation is recommended because the majority of complications occur early after the procedure.

Cardiac surgery and operative mortality in 1992 and 2002: the St Antonius experience

OBJECTIVE

Comparing the changes in open-heart surgical procedures and hospital mortality in 1992 with 2002.

DESIGN AND SETTING

Retrospective investigation at St Antonius Hospital in Nieuwegein.

METHOD

A comparison of the open-heart surgical procedures, hospital mortality and age distribution of the operated patients was made, using the database of the Department of Cardiothoracic Surgery.

RESULTS

The total number of open-heart surgical procedures increased. There were more combined procedures, aortic valve replacements and reconstructions of the thoracic aorta. The total number of reoperations decreased. In 2002 the use of an arterial conduit for coronary bypass procedures reached 94%, and the radial artery was used for the first time. The mean patient age and the hospital mortality were higher in 2002.

CONCLUSION

Comparing cardiovascular surgery in 1992 to 2002 showed an increase in complicated procedures and older age groups of patients. This may be the reason for higher overall mortality. The mean patient age increased considerably from 1992 to 2002, together with the number of combined procedures and aortic valve replacements with biological valve prostheses. These trends give cardiovascular surgery a challenging future, to treat the patient adequately and keeping the mortality and complication rates low.

Socioeconomic status and ischaemic heart disease mortality in 10 western European populations during the 1990s

OBJECTIVE

To assess the association between socioeconomic status and ischaemic heart disease (IHD) mortality in 10 western European populations during the 1990s.

DESIGN

Longitudinal study.

SETTING

10 European populations (95,009,822 person years).

METHODS

Longitudinal data on IHD mortality by educational level were obtained from registries in Finland, Norway, Denmark, England/Wales, Belgium, Switzerland, Austria, Turin (Italy), Barcelona (Spain), and Madrid (Spain). Age standardised rates and rate ratios (RRs) of IHD mortality by educational level were calculated by using Poisson regression.

RESULTS

IHD mortality was higher in those with a lower socioeconomic status than in those with a higher socioeconomic status among men aged 30-59 (RR 1.55, 95% confidence interval (CI) 1.51 to 1.60) and 60 years and over (RR 1.22, 95% CI 1.21 to 1.24), and among women aged 30-59 (RR 2.13, 95% CI 1.98 to 2.29) and 60 years and over (RR 1.36, 95% CI 1.33 to 1.38). Socioeconomic disparities in IHD mortality were larger in the Scandinavian countries and England/Wales, of moderate size in Belgium, Switzerland, and Austria, and smaller in southern European populations among men and younger women (p < 0.0001). For elderly women the north-south gradient was smaller and there was less variation between populations. No socioeconomic disparities in IHD mortality existed among elderly men in southern Europe.

CONCLUSIONS

Socioeconomic disparities in IHD mortality were larger in northern than in southern European populations during the 1990s. This partly reflects the pattern of socioeconomic disparities in cardiovascular risk factors in Europe. Population wide strategies to reduce risk factor prevalence combined with interventions targeted at the lower socioeconomic groups can contribute to reduce IHD mortality in Europe.

The current status of asthma in Korea

A systematic review of English and Korean articles published between 1990 and 2004 and a search of database and various online resources was conducted to determine the prevalences, mortality rates, socioeconomic burden, quality of life, and treatment pattern of asthma in Korean adults and children. Asthma morbidity and mortality in Korea are steadily increasing. The prevalence of asthma in Korea is estimated to be 3.9% and its severity is often underestimated by both physicians and patients. Mortality resulting from chronic lower respiratory diseases including asthma increased from 12.9 to 22.6 deaths per 100,000 of the population between 1992 and 2002. Disease severity, level of control, and symptom state were all found to negatively impact the quality of life of asthmatics. Although international and Korean asthma management guidelines are available, familiarity with and implementation of these guidelines by primary care physicians remain poor.

The exposure-response curve for ozone and risk of mortality and the adequacy of current ozone regulations

Time-series analyses have shown that ozone is associated with increased risk of premature mortality, but little is known about how O3 affects health at low concentrations. A critical scientific and policy question is whether a threshold level exists below which O3 does not adversely affect mortality. We developed and applied several statistical models to data on air pollution, weather, and mortality for 98 U.S. urban communities for the period 1987-2000 to estimate the exposure-response curve for tropospheric O3 and risk of mortality and to evaluate whether a "safe" threshold level exists. Methods included a linear approach and subset, threshold, and spline models. All results indicate that any threshold would exist at very low concentrations, far below current U.S. and international regulations and nearing background levels. For example, under a scenario in which the U.S. Environmental Protection Agency's 8-hr regulation is met every day in each community, there was still a 0.30% increase in mortality per 10-ppb increase in the average of the same and previous days' O3 levels (95% posterior interval, 0.15-0.45%). Our findings indicate that even low levels of tropospheric O3 are associated with increased risk of premature mortality. Interventions to further reduce O3 pollution would benefit public health, even in regions that meet current regulatory standards and guidelines.

Physician board certification and the care and outcomes of elderly patients with acute myocardial infarction

BACKGROUND

Patients and purchasers prefer board-certified physicians, but whether these physicians provide better quality of care and outcomes for hospitalized patients is unclear.

OBJECTIVE

We evaluated whether care by board-certified physicians after acute myocardial infarction (AMI) was associated with higher use of clinical guideline recommended therapies and lower 30-day mortality.

SUBJECTS AND METHODS

We examined 101,251 Medicare patients hospitalized for AMI in the United States and compared use of aspirin, beta-blockers, and 30-day mortality according to the attending physicians' board certification in family practice, internal medicine, or cardiology.

RESULTS

Board-certified family practitioners had slightly higher use of aspirin (admission: 51.1% vs 46.0%; discharge: 72.2% vs 63.9%) and beta-blockers (admission: 44.1% vs 37.1%; discharge: 46.2% vs 38.7%) than nonboard-certified family practitioners. There was a similar pattern in board-certified Internists for aspirin (admission: 53.7% vs 49.6%; discharge: 78.2% vs 68.8%) and beta-blockers (admission: 48.9% vs 44.1%; discharge: 51.2% vs 47.1). Board-certified cardiologists had higher use of aspirin compared with cardiologists certified in internal medicine only or without any board certification (admission: 61.3% vs 53.1% vs 52.1%; discharge: 82.2% vs 71.8% vs 71.5%) and beta-blockers (admission: 52.9% vs 49.6% vs 41.5%; discharge: 54.7% vs 50.6% vs 42.5%). In multivariate regression analyses, board certification was not associated with differences in 30-day mortality.

CONCLUSIONS

Treatment by a board-certified physician was associated with modestly higher quality of care for AMI, but not differences in mortality. Regardless of board certification, all physicians had opportunities to improve quality of care for AMI.

Applying a moving total mortality count to the cities in the NMMAPS database to estimate the mortality effects of particulate matter air pollution

OBJECTIVES

To apply a new method for estimating the association between daily ambient particulate matter air pollution (PM) and daily mortality to data from over 100 United States cities contained in the National Morbidity, Mortality, and Air Pollution Study (NMMAPS) database and to see whether the results from the 90 cities NMMAPS analysis are robust to this different modelling approach. This new method has recently been shown to provide improved estimates for the association between PM and daily mortality when every-day PM data are unavailable. It avoids the need for selecting a lag of PM at which the mortality effects of PM are to be investigated.

METHODS

With the aid of analytical methods and databases developed for NMMAPS, Poisson log linear models controlling for long term trends and weather effects were used to estimate the association between PM and mortality for cities in the NMMAPS database using the new method. A two stage Bayesian hierarchical model was then used to combine city specific estimates to form a national average PM mortality effect estimate.

RESULTS

A 10 microg/m3 increase in PM was associated with a 0.12% increment in total mortality and a 0.17% increment in cardiovascular and respiratory mortality. These results are consistent with those found in the NMMAPS analysis.

CONCLUSIONS

There is a statistically significant association between short term changes in PM and mortality on average for the cities contained in the NMMAPS database. These findings are further evidence that this widespread pollutant adversely affects public health.

Is hypercapnea a predictor of better survival in the patients who underwent mechanical ventilation for chronic obstructive pulmonary disease (COPD)?

BACKGROUND

There are contradictory reports concerning hypercapnia as a predictor of a better outcome in COPD. This study examined the clinical implications of hypercapnea in COPD patients (M:F = 59:19) who required mechanical ventilation.

METHODS

The clinical parameters at the time of MICU admission, the total ventilation time, the APACHE II score and the pulmonary function testing were retrospectively analyzed between the survivors and nonsurvivors.

RESULTS

Univariate analysis showed that compared with the nonsurvivors, the survivors had lower AaDO2 values (59.8 +/- 53.5 vs. 105.0 +/- 73.3 mmHg, p=0.000), higher PaCO2 values (64.9 +/- 16.0 vs. 48.9 +/- 17.8 mmHg, p=0.000), lower APACHE II scores (19.0 +/- 3.8 vs. 24.1 +/- 5.1, p=0.002), the more frequent application of initial noninvasive positive pressure ventilation (44.0 vs. 14.3%, p=0.008), and a lower combined rate of septic shock (4.0 vs. 39.3%, p=0.000). Multivariate analysis revealed that a lower PaCO2 (OR: 0.94, p=0.008), the presence of septic shock (OR: 10.16, p=0.011), a higher APACHE II score (OR: 1.22, p=0.040) and a longer ventilation time (OR: 1.002, p=0.041) were the risk factors for mortality. A lower PaCO2 was also verified as the predictor. for mortality by multivariate analysis when excluding septic shock.

CONCLUSIONS

Hypercapnia at admission is thought to be an independent predictor of better survival for the COPD patients who require mechanical ventilation.

Thyroid status, cardiovascular risk, and mortality in older adults

CONTEXT

Previous studies have suggested that subclinical abnormalities in thyroid-stimulating hormone levels are associated with detrimental effects on the cardiovascular system.

OBJECTIVE

To determine the relationship between baseline thyroid status and incident atrial fibrillation, incident cardiovascular disease, and mortality in older men and women not taking thyroid medication.

DESIGN, SETTING, AND PARTICIPANTS

A total of 3233 US community-dwelling individuals aged 65 years or older with baseline serum thyroid-stimulating hormone levels were enrolled in 1989-1990 in the Cardiovascular Health Study, a large, prospective cohort study.

MAIN OUTCOME MEASURES

Incident atrial fibrillation, coronary heart disease, cerebrovascular disease, cardiovascular death, and all-cause death assessed through June 2002. Analyses are reported for 4 groups defined according to thyroid function test results: subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism.

RESULTS

Individuals with overt thyrotoxicosis (n = 4) were excluded because of small numbers. Eighty-two percent of participants (n = 2639) had normal thyroid function, 15% (n = 496) had subclinical hypothyroidism, 1.6% (n = 51) had overt hypothyroidism, and 1.5% (n = 47) had subclinical hyperthyroidism. After exclusion of those with prevalent atrial fibrillation, individuals with subclinical hyperthyroidism had a greater incidence of atrial fibrillation compared with those with normal thyroid function (67 events vs 31 events per 1000 person-years; adjusted hazard ratio, 1.98; 95% confidence interval, 1.29-3.03). No differences were seen between the subclinical hyperthyroidism group and euthyroidism group for incident coronary heart disease, cerebrovascular disease, cardiovascular death, or all-cause death. Likewise, there were no differences between the subclinical hypothyroidism or overt hypothyroidism groups and the euthyroidism group for cardiovascular outcomes or mortality. Specifically, individuals with subclinical hypothyroidism had an adjusted hazard ratio of 1.07 (95% confidence interval, 0.90-1.28) for incident coronary heart disease.

CONCLUSION

Our data show an association between subclinical hyperthyroidism and development of atrial fibrillation but do not support the hypothesis that unrecognized subclinical hyperthyroidism or subclinical hypothyroidism is associated with other cardiovascular disorders or mortality.

Mortality prediction with a single general self-rated health question. A meta-analysis

OBJECTIVE

Health planners and policy makers are increasingly asking for a feasible method to identify vulnerable persons with the greatest health needs. We conducted a systematic review of the association between a single item assessing general self-rated health (GSRH) and mortality.

DATA SOURCES

Systematic MEDLINE and EMBASE database searches for studies published from January 1966 to September 2003.

REVIEW METHODS

Two investigators independently searched English language prospective, community-based cohort studies that reported (1) all-cause mortality, (2) a question assessing GSRH; and (3) an adjusted relative risk or equivalent. The investigators searched the citations to determine inclusion eligibility and abstracted data by following a standardized protocol. Of the 163 relevant studies identified, 22 cohorts met the inclusion criteria. Using a random effects model, compared with persons reporting "excellent" health status, the relative risk (95% confidence interval) for all-cause mortality was 1.23 [1.09, 1.39], 1.44 [1.21, 1.71], and 1.92 [1.64, 2.25] for those reporting "good,""fair," and "poor" health status, respectively. This relationship was robust in sensitivity analyses, limited to studies that adjusted for co-morbid illness, functional status, cognitive status, and depression, and across subgroups defined by gender and country of origin.

CONCLUSIONS

Persons with "poor" self-rated health had a 2-fold higher mortality risk compared with persons with "excellent" self-rated health. Subjects' responses to a simple, single-item GSRH question maintained a strong association with mortality even after adjustment for key covariates such as functional status, depression, and co-morbidity.

Clinical significance of platelet count at day +60 after allogeneic peripheral blood stem cell transplantation

Thrombocytopenia (TP) is a frequent complication after allogeneic stem cell transplantation (SCT) and regarded as a poor prognostic factor, especially in patients with chronic graft-versus-host disease (GVHD), although various factors were related to the development of TP after allogeneic SCT. Sixty-three patients receiving allogeneic peripheral blood stem cell transplantation (PBSCT) were stratified according to platelet count (PC) at day +60 and analyzed in terms of overall survival (OS) and the incidence of non-relapse mortality (NRM). Ten patients (15.9%) were stratified in group 1 (PC </= 29 x 10(9)/L), 23 patients (36.5%) in group 2 (PC 30-79 x 10(9)/L), and 30 patients in group 3 (PC >/= 80 x 10(9)/L). Group 3 was associated with lower incidence of extensive chronic GVHD (p=0.013), better 3-yr OS (p=0.0030), and lower NRM rate (p<0.0001). In multivariate analyses, the PC at day +60 was identified as an independent prognostic factor (p=0.003) together with CD34+ cell dose (p<0.001), disease risk (p=0.004), and acute GVHD (p=0.033) in terms of NRM, and the PC (p=0.047) and CD34+ cell dose (p=0.026) in terms of incidence of infectious events. Measuring the platelet count at day +60 is a simple method for predicting the risk of chronic GVHD development and prognosis after allogeneic PBSCT.

Myocardial revascularisation in women: evaluation of hospital mortality and morbidity

BACKGROUND

Although women are reported to be at higher risk for mortality and morbidity after coronary artery bypass graft (CABG), there is no consensus in literature.

METHOD

Pre-, peri- and postoperative hospital data of 8578 patients undergoing an isolated myocardial revascularisation from January 1987 to December 2004 were analysed. Of these patients, 2083 (24.3%) were female.

RESULTS

Female patients were significantly older (p=0.001), and risk factors as diabetes (p=0.001), hypertension (p=0.001), hyperlipidaemia (p=0.001) were significantly more prevalent than in men. The incidence of preoperative myocardial infarction (p=0.001) and triple-vessel disease (p=0.001) was lower, but the incidence of unstable angina (NYHA IV) (p=0.001) was significantly higher than in men. Significantly fewer women (p=0.04) received an arterial graft. Postoperatively, there was no significant difference in the registered morbidity, with the exception of a lower incidence of female patients with non-sinus rhythm (p=0.001) and a higher incidence of pulmonary problems (p=0.006). Hospital mortality was not significantly different between the genders: 3.5 vs. 3.4% (p=0.9). A preoperative myocardial infarction was identified as the only independent predictor for hospital mortality.

CONCLUSION

The preoperative profiles of women and men undergoing CABG are dissimilar. However, the incidences of hospital mortality, and morbidity were not statistically different. Female gender was not identified as predictor for death or adverse outcome.

Survival analysis to estimate association between short-term mortality and air pollution

BACKGROUND

Ecologic studies are commonly used to report associations between short-term air pollution and mortality. In such studies, the unit of observation is the day rather than the individual. Moreover, individual data on the subjects are rarely available, which limits the assessment of individual risk factors. These associations can also be investigated using case-crossover studies. However, by definition, individual risk factors are not studied, and such studies analyze only dead subjects, which limits the statistical power.

OBJECTIVE

We suggest that the survival analysis is more suitable when cohorts are examined with a time-dependent ecologic exposure. To our knowledge, to date this type of analysis has never been proposed.

DESIGN, PARTICIPANTS, MEASUREMENTS

In the present study we used a Cox proportional hazards model to investigate the distribution over time of the short-term effect of black smoke and sulfur dioxide in 439 nonaccidental and 158 cardiorespiratory deaths among the 1,469 subjects of the Personnes Agées QUID (PAQUID) cohort in Bordeaux, France. The model has a delayed entry and a polynomial distributed lag from 0 to 5 days. Results are adjusted for individual risk factors, temperature, relative humidity, weekday, season, influenza epidemics, and a time function to control temporal trends.

RESULTS

We identified a positive and significant association between cardiorespiratory mortality and black smoke, with a 24% increase in deaths 3 days after a 10-microg/m3 increase in black smoke (95% confidence interval, 4-47%).

CONCLUSIONS

We conclude that the Cox proportional hazards model with time-dependent covariates is very suitable to investigate simultaneously the short-term effect of air pollution on health and the effect of individual risk factors on a cohort study.

QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization

QTc interval prolongation is associated with increased mortality rates in patients with advanced heart failure. We investigated the predictive value of prolonged QTc interval in 567 patients with heart failure who were undergoing coronary artery bypass graft surgery The patients were in New York Heart Association class III or IV, with left ventricular ejection fractions of 0.40 or less. Before surgery, the QT interval duration was measured in leads II and V4 of the standard electrocardiogram and corrected by use of the Bazett formula. The QTc interval was prolonged (>440 msec) in 243 patients (43%) and normal in 324 (57%). The 2 study groups--prolonged QTc versus normal QTc--did not differ in terms of age (62 +/- 11 years vs 64 +/- 10 years, P=0.65), sex (80% male vs 76% male, P=0.31), ejection fraction (0.29 +/- 0.08 vs 0.29 +/- 0.09, P=0.72), hypertension (82% vs 78%, P=0.34), or diabetes (11% vs 7%, P=0.10). Within 1 month after coronary artery bypass grafting, 22 of 243 patients (9.1%) in the prolonged QTc group died, compared with 5 of 324 in the normal QTc group (1.5%) (P=0.0001). QTc interval prolongation was the only independent predictor of postoperative mortality on multivariate analysis (P=0.002). We conclude that patients with heart failure and preoperative QTc interval prolongation have increased mortality rates after coronary artery bypass grafting.

Changing the burden of COPD mortality

COPD is a major cause of mortality and morbidity worldwide with an estimated 2.75 million deaths in 2000 (fourth leading cause of death). In addition to the considerable morbidity and mortality associated with COPD, this disease incurs significant healthcare and societal costs. Current COPD guidelines acknowledge that the following can improve COPD mortality: smoking cessation; long-term oxygen therapy; and lung volume reduction surgery in small subsets of COPD patients. To date, no randomized controlled trials have demonstrated an effect of pharmacological treatment on mortality, although several observational studies suggest that both long-acting bronchodilators and inhaled corticosteroids may provide a survival benefit. The possibility that these treatments reduce mortality is being investigated in ongoing large-scale clinical trials.

Causes of mortality and risk factors for injury mortality among children in the agricultural health study

Farm children face unique health risks due to sharing their residential environment with hazardous machinery and materials. Causes of mortality among farm children have not been comprehensively described.

OBJECTIVE

In the Agricultural Health Study (AHS) cohort, we examined causes of mortality among 21,360 children in Iowa and North Carolina between 1975 and 1998.

METHODS

We matched identifying information for children provided by mothers on self-administered questionnaires to state death registries (1975-1998). Data on farm and family characteristics were provided by parents via enrollment questionnaires (1993-1997). Standardized mortality ratios (SMRs) were calculated, using state mortality data to generate expected deaths. We used logistic regression to examine parent, child and farm characteristics associated with injury mortality.

RESULTS

There were 162 deaths in Iowa (SMR = 0.69; 95% confidence interval (CI) = 0.60, 0.81) and 26 deaths in North Carolina (SMR = 0.42; 95% CI = 0.28, 0.61) in children aged 0-19 years. This deficit was largely due to deaths in the first year of life. Although deaths from overall unintentional injury were not increased, excess agricultural machinery mortality was observed in Iowa (SMR = 9.25; 95% CI = 5.12, 16.70). In case-control comparisons, maternal age less than 25 years at child's birth (OR = 2.17; 95% CI = 1.05, 4.49) and having more than 2 children in the family (OR = 2.79; 95% CI = 1.47, 5.30) were associated with increased child injury mortality. For children under 14 years, participation in farm work was associated with increased risk of agricultural machine-related mortality (OR = 3.92; 95% CI = 1.04, 14.78).

CONCLUSIONS

Parent and child characteristics associated with child injury mortality could be used to target farm safety interventions.

Curative resection for left-sided pancreatic malignancy

BACKGROUND

Surgical technique in pancreatic cancer has seen significant developments, but much of the knowledge refers to pancreatic head carcinoma. Reports on the management of tumours of the body and tail have been less frequent. Current knowledge teaches that adenocarcinomas of the body and tail of the pancreas have a worse prognosis. The aim of this study is to report the short- and long-term outcome in 20 patients with left-sided pancreatic malignancy, where 'resection for cure' was done.

PATIENTS AND METHODS

Retrospective study of demographic data, symptomatology, diagnostic methods, operative management, pathology report, postoperative morbidity and mortality.

RESULTS

Postoperative complications were seen in 40% of patients. One patient died on day 5 from sepsis with multiple organ failure. Other complications were intra-abdominal bleeding, bleeding from the gastroentero-anastomosis, postoperative jaundice, pleural exudate, wound dehiscence and intra-abdominal abscess. The patients with ductal adenocarcinoma had a median survival of 14 months and a 5-year survival of 17%. The median survival for the whole group of patients was 17 months and the 5-year survival was 23%. One patient with malignant insulinoma and two patients with adenocarcinoma had a survival exceeding 5 years (98, 174 and 183 months, respectively).

DISCUSSION

Selected patients with left-sided pancreatic adenocarcinoma may be operated on with results similar to pancreaticoduodenectomy (Whipple procedure) for cancer of the pancreatic head regarding postoperative morbidity and mortality as well as long-term survival. Thus, although left-sided pancreatic cancer generally appears at a more advanced stage, it seems true that treatment results are similar if radical excision can be achieved.

Incorporation of rhodamine B into male tobacco budworm moths Heliothis virescens to use as a marker for mating studies

Rhodamine B, a dye commonly used in a variety of biological studies was incorporated into the bodies of male tobacco budworm moths, Heliothis virescens (Lepidoptera: Noctuidae), by allowing them to feed freely on 0.1% rhodamine dissolved in a 10% sucrose solution. After exposing males for one to three days to this pigment, rhodamine was clearly detectable in >82% of spermatophores extracted from untreated females. The intake of this dye did not affect the life span, the production of eggs or the capacity of moths to copulate when compared with moths fed only a sucrose solution or water. Rhodamine B was easily identifiable externally but was more apparent internally in males after only one day of exposure to the pigment. Even at this short feeding duration, rhodamine was detectable in >50% of males 5 days after feeding stopped. Longer exposure to the dye significantly increased the percentage stained. Detection of rhodamine was slightly enhanced by the use of ultraviolet light. The dye accumulation in internal abdominal organs was a better indicator of the presence of the pigment than external contamination of the moth. The use of the method described in this report can be a tool for the rapid incorporation of a low cost dye in the tobacco budworm for biological, behavioral and genetic studies.

Fine particulate air pollution and mortality in nine California counties: results from CALFINE

Many epidemiologic studies provide evidence of an association between daily counts of mortality and ambient particulate matter<10 microm in diameter (PM10). Relatively few studies, however, have investigated the relationship of mortality with fine particles [PM<2.5 microm in diameter (PM2.5)], especially in a multicity setting. We examined associations between PM2.5 and daily mortality in nine heavily populated California counties using data from 1999 through 2002. We considered daily counts of all-cause mortality and several cause-specific subcategories (respiratory, cardiovascular, ischemic heart disease, and diabetes). We also examined these associations among several subpopulations, including the elderly (>65 years of age), males, females, non-high school graduates, whites, and Hispanics. We used Poisson multiple regression models incorporating natural or penalized splines to control for covariates that could affect daily counts of mortality, including time, seasonality, temperature, humidity, and day of the week. We used meta-analyses using random-effects models to pool the observations in all nine counties. The analysis revealed associations of PM2.5 levels with several mortality categories. Specifically, a 10-microg/m3 change in 2-day average PM2.5 concentration corresponded to a 0.6% (95% confidence interval, 0.2-1.0%) increase in all-cause mortality, with similar or greater effect estimates for several other subpopulations and mortality subcategories, including respiratory disease, cardiovascular disease, diabetes, age>65 years, females, deaths out of the hospital, and non-high school graduates. Results were generally insensitive to model specification and the type of spline model used. This analysis adds to the growing body of evidence linking PM2.5 with daily mortality.

Digoxin and reduction in mortality and hospitalization in heart failure: a comprehensive post hoc analysis of the DIG trial

AIMS

To determine the effects of digoxin on all-cause mortality and heart failure (HF) hospitalizations, regardless of ejection fraction, accounting for serum digoxin concentration (SDC).

METHODS AND RESULTS

This comprehensive post-hoc analysis of the randomized controlled Digitalis Investigation Group trial (n=7788) focuses on 5548 patients: 1687 with SDC, drawn randomly at 1 month, and 3861 placebo patients, alive at 1 month. Overall, 33% died and 31% had HF hospitalizations during a 40-month median follow-up. Compared with placebo, SDC 0.5-0.9 ng/mL was associated with lower mortality [29 vs. 33% placebo; adjusted hazard ratio (AHR), 0.77; 95% confidence interval (CI), 0.67-0.89], all-cause hospitalizations (64 vs. 67% placebo; AHR, 0.85; 95% CI, 0.78-0.92) and HF hospitalizations (23 vs. 33% placebo; AHR, 0.62; 95% CI, 0.54-0.72). SDC> or =1.0 ng/mL was associated with lower HF hospitalizations (29 vs. 33% placebo; AHR, 0.68; 95% CI, 0.59-0.79), without any effect on mortality. SDC 0.5-0.9 reduced mortality in a wide spectrum of HF patients and had no interaction with ejection fraction >45% (P=0.834) or sex (P=0.917).

CONCLUSIONS

Digoxin at SDC 0.5-0.9 ng/mL reduces mortality and hospitalizations in all HF patients, including those with preserved systolic function. At higher SDC, digoxin reduces HF hospitalization but has no effect on mortality or all-cause hospitalizations.

Long-term survival of persons ventilator dependent after spinal cord injury

BACKGROUND/OBJECTIVE

Identify factors related to long-term survival, and quantify their effect on mortality and life expectancy.

SETTING

Model spinal cord injury systems of care across the United States.

STUDY DESIGN

Survival analysis of persons with traumatic spinal cord injury who are ventilator dependent at discharge from inpatient rehabilitation and who survive at least 1 year after injury.

METHODS

Logistic regression analysis on a data set of 1,986 person-years occurring among 319 individuals injured from 1973 through 2003.

RESULTS

The key factors related to long-term survival were age, time since injury, neurologic level, and degree of completeness of injury. The life expectancies were modestly lower than previous estimates. Pneumonia and other respiratory conditions remain the leading cause of death but account for only 31% of deaths of known causes.

CONCLUSIONS

Whereas previous research has suggested a dramatic improvement in survival over the last few decades in this population, this is only the case during the critical first few years after injury. There was no evidence for such a trend in the subsequent period.

Predictive value of arterial ammonia for complications and outcome in acute liver failure

BACKGROUND AND AIMS

In acute liver failure (ALF), the brain is exposed to high levels of ammonia. Human studies defining the clinical significance of ammonia in ALF are lacking. This prospective study evaluated the relationship of arterial ammonia levels at admission to complications and survival among patients with ALF.

METHODS

Eighty consecutive ALF patients admitted from March 2001 to December 2003 were followed up until death or complete recovery. All had arterial ammonia estimation at admission (enzymatic method). Logistic regression analysis was performed to identify independent predictors of mortality.

RESULTS

Forty two (52.5%) patients died. Non-survivors had significantly higher median ammonia levels than survivors (174.7 v 105.0 micromol/l; p<0.001). An arterial ammonia level of > or = 124 micromol/l was found to predict mortality with 78.6% sensitivity and 76.3% specificity, and had 77.5% diagnostic accuracy. Patients with higher ammonia levels also developed more complications, including deeper encephalopathy (p = 0.055), cerebral oedema (p = 0.020), need for ventilation (p<0.001), and seizures (p = 0.006). Logistic regression analysis showed that pH, presence of cerebral oedema, and arterial ammonia at admission were independent predictors of mortality (odds ratios 6.6, 12.6, and 10.9, respectively). Incorporating these variables, a score predicting mortality risk at admission was derived: 2.53 + 2.91 ammonia + 2.41 oedema + 1.40 pH, where ammonia is scored as 0 (if <124 micromol/l) or 1 (if > or =124 micromol/l); oedema is scored as 0 (absent) or 1(present); and pH is scored as 1 (if < or =7.40) or 0 (if >7.40). Levels of partial pressure of ammonia were equally correlated with outcome.

CONCLUSION

Arterial ammonia at presentation is predictive of outcome and can be used for risk stratification. Ammonia lowering therapies in patients with ALF should be evaluated.

Pulmonary resection for non-small cell lung cancer in patients with prior spinal cord injury

BACKGROUND/OBJECTIVE

We sought to determine the clinical course of patients with spinal cord injury (SCI) who subsequently developed bronchogenic carcinoma and underwent pulmonary resection.

METHODS

A nationwide retrospective study was conducted of all veterans at Department of Veterans Affairs Medical Centers for fiscal years 1993-2002 who were diagnosed with SCI, subsequently developed non-small cell lung cancer, and were surgically treated with curative intent. Inclusion criteria included American Spinal Injury Association type A injury (complete loss of neural function distal to the injury site) and traumatic etiology. Data were compiled from national Department of Veterans Affairs data sets and supplemented by operative reports, pathology reports, progress notes, and discharge summaries.

RESULTS

Seven patients met the inclusion/exclusion criteria and were considered evaluable. Five (71%) had one or more comorbid conditions in addition to their SCIs. All 7 underwent pulmonary lobectomy. Postoperative complications occurred in 4 patients (57%). Two patients died postoperatively on days 29 and 499, yielding a 30-day mortality rate of 14% and an in-hospital mortality rate of 29%.

CONCLUSIONS

This seems to be the only case study in the English language literature on this topic. Patients with SCI who had resectable lung cancer had a high incidence of comorbid conditions. Those who underwent curative-intent surgery had high morbidity and mortality rates. Available evidence suggests that SCI should be considered a risk factor for adverse outcomes in major surgery of all types, including operations for primary lung cancer.

Workgroup report: workshop on source apportionment of particulate matter health effects--intercomparison of results and implications

Although the association between exposure to ambient fine particulate matter with aerodynamic diameter < 2.5 microm (PM2.5) and human mortality is well established, the most responsible particle types/sources are not yet certain. In May 2003, the U.S. Environmental Protection Agency's Particulate Matter Centers Program sponsored the Workshop on the Source Apportionment of PM Health Effects. The goal was to evaluate the consistency of the various source apportionment methods in assessing source contributions to daily PM2.5 mass-mortality associations. Seven research institutions, using varying methods, participated in the estimation of source apportionments of PM2.5 mass samples collected in Washington, DC, and Phoenix, Arizona, USA. Apportionments were evaluated for their respective associations with mortality using Poisson regressions, allowing a comparative assessment of the extent to which variations in the apportionments contributed to variability in the source-specific mortality results. The various research groups generally identified the same major source types, each with similar elemental makeups. Intergroup correlation analyses indicated that soil-, sulfate-, residual oil-, and salt-associated mass were most unambiguously identified by various methods, whereas vegetative burning and traffic were less consistent. Aggregate source-specific mortality relative risk (RR) estimate confidence intervals overlapped each other, but the sulfate-related PM2.5 component was most consistently significant across analyses in these cities. Analyses indicated that source types were a significant predictor of RR, whereas apportionment group differences were not. Variations in the source apportionments added only some 15% to the mortality regression uncertainties. These results provide supportive evidence that existing PM2.5 source apportionment methods can be used to derive reliable insights into the source components that contribute to PM2.5 health effects.

The impact of cigarette smoking on mortality, quality of life, and comorbid illness among HIV-positive veterans

BACKGROUND

The impact of smoking on outcomes among those with HIV infection has not been determined in the era of highly active antiretroviral therapy (HAART).

STUDY OBJECTIVE

Determine the impact of smoking on morbidity and mortality in HIV-positive patients post-HAART.

DESIGN

Prospective observational study.

PARTICIPANTS

Eight hundred and sixty-seven HIV-positive veterans enrolled in the Veterans Aging Cohort 3 Site Study.

MEASUREMENTS

Clinical data were collected through patient questionnaire, International Classification of Diseases--9th edition codes, and standardized chart extraction, and laboratory and mortality data through the national VA database. Quality of life was assessed with the physical component summary (PCS) of the Short-Form 12.

RESULTS

Current smokers had increased respiratory symptoms, chronic obstructive pulmonary disease (COPD), and bacterial pneumonia. In analyses adjusted for age, race/ethnicity, CD4 cell count, HIV RNA level, hemoglobin, illegal drug and alcohol use, quality of life was substantially decreased (beta=-3.3, 95% confidence interval [CI] -5.3 to -1.4) and mortality was significantly increased (hazard ratio 1.99, 95% CI 1.03 to 3.86) in current smokers compared with never smokers.

CONCLUSIONS

HIV-positive patients who currently smoke have increased mortality and decreased quality of life, as well as increased respiratory symptoms, COPD, and bacterial pneumonia. These findings suggest that smoking cessation should be emphasized for HIV-infected patients.

The association between fatal coronary heart disease and ambient particulate air pollution: Are females at greater risk?

The purpose of this study was to assess the effect of long-term ambient particulate matter (PM) on risk of fatal coronary heart disease (CHD). A cohort of 3,239 nonsmoking, non-Hispanic white adults was followed for 22 years. Monthly concentrations of ambient air pollutants were obtained from monitoring stations [PM < 10 microm in aerodynamic diameter (PM10), ozone, sulfur dioxide, nitrogen dioxide] or airport visibility data [PM < 2.5 microm in aerodynamic diameter (PM2.5)] and interpolated to ZIP code centroids of work and residence locations. All participants had completed a detailed lifestyle questionnaire at baseline (1976), and follow-up information on environmental tobacco smoke and other personal sources of air pollution were available from four subsequent questionnaires from 1977 through 2000. Persons with prevalent CHD, stroke, or diabetes at baseline (1976) were excluded, and analyses were controlled for a number of potential confounders, including lifestyle. In females, the relative risk (RR) for fatal CHD with each 10-microg/m3 increase in PM2.5 was 1.42 [95% confidence interval (CI), 1.06-1.90] in the single-pollutant model and 2.00 (95% CI, 1.51-2.64) in the two-pollutant model with O3. Corresponding RRs for a 10-microg/m3 increase in PM(10-2.5) and PM10 were 1.62 and 1.45, respectively, in all females and 1.85 and 1.52 in postmenopausal females. No associations were found in males. A positive association with fatal CHD was found with all three PM fractions in females but not in males. The risk estimates were strengthened when adjusting for gaseous pollutants, especially O3, and were highest for PM2.5. These findings could have great implications for policy regulations.

The bigger the healthier: are the limits of BMI risk changing over time?

The body mass index (BMI) is often used as a predictor of overweight and obesity. There is, however, an important debate among international specialists as to what the risk limits should be, and where the cut-off points should be located. In the United States, for instance, adults with a BMI between 25 and 30 are considered overweight, while adults with a BMI of 30 or higher are considered obese. Nevertheless some researchers, especially in developing countries, claim that the limits established for the US are too permissive, and that the threshold to define obese adults should be set lower for other nationalities and ethnicities. This paper analyzes the mortality risks for different BMI levels of two populations of American adult men. The first population lived during the last quarter of the 19th century and the early 20th century. These men were drawn from a random sample of Union Army veterans who fought during the American Civil War (1861-1865). A contemporary sample of men was drawn from the first wave of the National Health and Nutrition Examination Survey (NHANES I) conducted between 1971 and 1975. The results indicate that the frontier of overweight and obesity are expanding over time, such that the potential risk is nowadays associated with higher levels of BMI. The finding may imply that differences in BMI cut-off points are not only cross ethnic, but also occur for similar ethnicities across time.

Trends in mortality after hospital admission for liver cirrhosis in an English population from 1968 to 1999

BACKGROUND

Population based mortality rates from liver cirrhosis, and alcohol consumption, have increased sharply in Britain in the past 35 years. Little is known about the long term trends over time in mortality rates after hospital admission for liver cirrhosis.

AIMS

To analyse time trends in mortality in the year after admission for liver cirrhosis from 1968 to 1999.

SUBJECTS

A total of 8192 people who were admitted to hospital in a defined population of Southern England.

METHODS

Analysis of hospital discharge statistics linked to death certificate data. The main outcome measures were case fatality rates (CFRs) and standardised mortality ratios (SMRs).

RESULTS

At 30 days after admission, CFR was 15.9% and the SMR was 93 (86 in men and 102 in women, compared with 1 in the general population). At one year, the overall CFR was 33.6% and SMR was 16.3. There was no improvement from 1968 to 1999 in mortality rates. SMRs were highest for alcoholic cirrhosis of the liver (27.4 at one year) but lower for biliary cirrhosis (11.4) and chronic hepatitis (10.0). Mortality from most of the main causes of death, including accidents and suicides, was increased.

CONCLUSIONS

The high mortality rates after hospital admission, and the fact that they have not fallen in the past 30 years, show that liver cirrhosis remains a disease with a very poor prognosis. Increased mortality from accidents, suicides, and mental disorders, particularly among those with alcoholic cirrhoses, indicates that prognosis is influenced by behavioural as well as by physical pathology.

Depression, cardiovascular disease, diabetes, and two-year mortality among older, primary-care patients

OBJECTIVE

Depression is a major contributor to death and disability, but few follow-up studies of depression have been carried out in the primary-care setting. The authors sought to assess whether depression in older patients is associated with increased mortality after a 2-year follow-up interval and to estimate the population-attributable fraction (PAF) of depression on mortality in older primary-care patients.

METHODS

Longitudinal cohort analysis was carried out in 20 primary-care practices. Participants were identified though a two-stage, age-stratified (60-74 or 75+) depression screening of randomly sampled patients; enrollment included patients who screened positive and a random sample of screened-negative patients. In all, 1,226 persons were assessed at baseline. Vital status at 2 years was the outcome of interest.

RESULTS

Of 1,226 persons in the sample, 598 were classified as depressed. After 2 years, 64 persons had died. Persons with depression at baseline were more likely to die at the end of the 2-year follow-up interval than were persons without depression, even after accounting for potentially influential covariates such as whether the participant reported a history of myocardial infarction (MI) or diabetes.

CONCLUSIONS

Among older, primary-care patients over the course of a 2-year follow-up interval, depression contributed as much to mortality as did MI or diabetes.

A practical method for monitoring general practice mortality in the UK: findings from a pilot study in a health board of Northern Ireland

BACKGROUND

The Baker report into Dr Harold Shipman's murders recommended monitoring mortality in general practice, but there is currently no practical method available to implement this.

AIM

To monitor mortality rates in response to the Baker report and to use the data to improve quality of care.

DESIGN OF STUDY

Prospective mortality monitoring study.

SETTING

Eastern Health and Social Services Board, Northern Ireland.

METHOD

Linked quarterly mortality data from 1994-2001 were compiled for 114 general practices in Eastern Health and Social Services Board in Northern Ireland. Cross-sectional control charts compared crude and adjusted mortality rates across all the practices. Longitudinal control charts analysed quarterly mortality rates over 28 quarters within each practice. Practices were sent their own control charts and invited to feedback workshops. Special cause variation in mortality was investigated as follows: checks on data, case-mix, practice structures, processes of care and finally individual carers.

RESULTS

Age, sex and deprivation adjusted cross-sectional control charts identified 18 practices as showing special cause variation in their mortality (11 high and 7 low). Assignable causes were found for all high special cause practices: large numbers of nursing home patients (six practices), very high levels of deprivation and high morbidity not captured by our case-mix adjustment (five practices). For three of seven low special cause practices, case-mix adjustment underestimated affluence and overestimated morbidity levels. Feedback indicated widespread support for the principle of monitoring, but concerns about the public disclosure of mortality data.

CONCLUSIONS

We have successfully developed and piloted a general practice mortality monitoring system with the support and participation of local stakeholders. This used control charts for analysis and followed a scientific strategy for investigating special cause variation.

Predominant effect of kidney disease on mortality in Pima Indians with or without type 2 diabetes

BACKGROUND

We examined the effect of kidney disease (KD) on mortality in nondiabetic and diabetic Pima Indians aged > or = 45 years old.

METHODS

Deaths and person-years of follow-up were stratified in a time-dependent fashion into categories of (1) no proteinuria and normal serum creatinine (SCr); (2) proteinuria and normal SCr; (3) high SCr [SCr > or = 133 micromol/L (1.5 mg/dL) in men, > or = 124 micromol/L (1.4 mg/dL) in women] but not on renal replacement therapy (RRT); or (4) RRT.

RESULTS

Among 1993 subjects, 55.8% had type 2 diabetes at baseline. Overall death rates increased with declining kidney function in both the nondiabetic and diabetic subjects (P < 0.0001). Death rates were similar in nondiabetic and diabetic subjects with comparable levels of kidney function, although the number of deaths among nondiabetic subjects with advanced KD was small. Infections and malignancy were the leading causes of death in nondiabetic subjects with KD. Among diabetic subjects, overall mortality increased with diabetes duration (P = 0.0001) and was highest in those on RRT (P < 0.0001). High SCr was associated with higher death rates from cardiovascular disease (CVD), diabetic nephropathy (DN), infections, and malignancy.

CONCLUSION

Death rates increased comparably with worsening kidney function in both nondiabetic and diabetic subjects and were similar in nondiabetic and diabetic subjects without KD. KD was associated with excess mortality from DN, CVD, infections, and malignancy in diabetic subjects, and from infections in those without diabetes.

Using moving total mortality counts to obtain improved estimates for the effect of air pollution on mortality

In many cities of the United States, measurements of ambient particulate matter air pollution (PM) are available only once every 6 days. Time-series studies conducted in these cities that investigate the relationship between mortality and PM are restricted to using a single day's PM as the measure of PM exposure. This is undesirable because current evidence suggests that the effects of PM on mortality are spread over multiple days. And studies have shown that using a single day's PM as the measure of PM exposure can result in estimates that have a large negative bias. In this article, I introduce a new model for estimating the mortality effects of PM when only every-sixth-day PM data are available. This new model uses information available in the daily mortality time series to infer otherwise lost information about the effect of PM on mortality over a period of more than a single day. This new model typically offers an increase in both statistical estimation precision and accuracy compared with existing models.

The effects of price competition and reduced subsidies for uncompensated care on hospital mortality

OBJECTIVE

To determine whether hospital mortality rates changed in New Jersey after implementation of a law that changed hospital payment from a regulated system based on hospital cost to price competition with reduced subsidies for uncompensated care and whether changes in mortality rates were affected by hospital market conditions.

DATA SOURCES/STUDY SETTING

State discharge data for New Jersey and New York from 1990 to 1996. Study Design. We used an interrupted time series design to compare risk-adjusted in-hospital mortality rates between states over time. We compared the effect sizes in markets with different levels of health maintenance organization penetration and hospital market concentration and tested the sensitivity of our results to different approaches to defining hospital markets.

DATA COLLECTION/EXTRACTION METHODS

The study sample included all patients under age 65 admitted to New Jersey or New York hospitals with stroke, hip fracture, pneumonia, pulmonary embolism, congestive heart failure, hip fracture, or acute myocardial infarction (AMI).

PRINCIPAL FINDINGS

Mortality among patients in New Jersey improved less than in New York by 0.4 percentage points among the insured (p=.07) and 0.5 percentage points among the uninsured (p=.37). There was a relative increase in mortality for patients with AMI, congestive heart failure, and stroke, especially for uninsured patients with these conditions, but not for patients with the other four conditions we studied. Less competitive hospital markets were significantly associated with a relative decrease in mortality among insured patients.

CONCLUSIONS

Market-based reforms may adversely affect mortality for some conditions but it appears the effects are not universal. Insured patients in less competitive markets fared better in the transition to price competition.

Extraordinary starvation resistance in Temnothorax rugatulus (Hymenoptera, Formicidae) colonies: Demography and adaptive behavior

Ant colony mortality has not been sufficiently studied, even though it is crucial for understanding social insect population biology and can serve as an important model for general aging and mortality processes. Particularly, studies on proximate mechanisms on mortality and stress resistance of ant colonies are lacking. This study explores the long-term colony starvation resistance of the small myrmecine ant Temnothorax rugatulus. We report extraordinary starvation resistance in the 21 colonies investigated, as most survived the eight months of total starvation. Furthermore, we studied demographic and behavioral changes over the experimental period. Brood decline began first (after two months) and mortality was highest, worker decline was intermediate, and queen mortality started latest and remained lowest. We found brood (its relative change during the first four months and the level of brood relative to colony size) to be the only significant predictor of colony starvation resistance, but not the degree of polygyny. As expected, rates of trophallaxis increased during the starvation period while colony activity bouts occurred more frequently but were much shorter, leading to an overall decrease in activity levels. This study is the first to comprehensively study mechanisms of starvation resistance in ant colonies, linking demography and behavior.