Population profile of the United States 1984/85.
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Americas↗
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Results for “Population Projection--statistics”
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World population beyond six billion.
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Birth Rate↗
Methods for national population forecasts: a review.
"Three widely used classes of methods for forecasting national populations are reviewed: demographic accounting/cohort-component methods for long-range projections, statistical time series methods for short-range forecasts, and structural modeling methods for the simulation and forecasting of the effects of policy changes. In each case, the major characteristics, strengths, and weaknesses of the methods are described. Factors that place intrinsic limits on the accuracy of population forecasts are articulated. Promising lines of additional research by statisticians and demographers are identified for each class of methods and for population forecasting generally."
Cohort Studies↗
Effective dose equivalent and associated risks from mass chest radiography in Kuwait.
The number of x-ray examinations performed on persons undergoing mass chest radiography in Kuwait reached a maximum of 1.858 X 10(5) in 1982 with miniature radiography (70 mm) claiming more than 90% of the total number and the rest done with the large film technique. The annual prevalence of asymptomatic tuberculosis patients diagnosed by x rays, as reported by the project statistics, does not, in our opinion, justify exposing such a large population. In this paper, the effective dose equivalent is calculated from both miniature and large film mass chest radiography as applied in Kuwait. The values obtained are 283 mu Sv and 35.5 mu Sv, respectively. These figures yield calculated risks of fatal malignancies per examination of 3.37 X 10(-6) and 0.422 X 10(-6), respectively. The annual collective effective dose equivalent to the population undergoing mass chest radiography in Kuwait during the 7 y 1977-1983 is found to vary between 38-48 man-Sv. These figures are used to calculate an average of 0.5 additional cases of fatal malignancies per year, or about 12 excess fatalities in the forthcoming 25-y period if the number of mass chest x-ray examinations stays at its existing level. A total of 98% of these calculated excess fatalities result from the predominant technique, miniature radiography.
Adolescent↗
Nepal: NFP/MCH Project's prime target.
Sterilization as a means of permanent family planning will be the prime target of the Nepal Family Planning and Maternity and Child Health Project in the current fiscal year. Under the permanent sterilization scheme, the project plans to open 18 laparoscopic camps in addition to 34 vasectomy camps in different parts of the country. The 146 mobile teams of the project sent to different parts of the country performed vasectomies on over 9000 males in the previous fiscal year. According to project statistics, more than 38,000 males have undergone vasectomy so far in Nepal. The rate of population growth is estimated to continue to increase by 3% in the next 5 years. This estimate is much higher than the original estimate made during the formation of the current 5-year plan.
Asia↗
Nursing workforce management: using benchmarking for planning and outcomes monitoring.
The goal of maintaining the balance between demand for nursing care and the supply of nurses is the basis for state and regional planning to meet future nursing workforce needs. Projecting nursing supply needs solely on the basis of historical registered nurse to population ratios does not specifically consider the healthcare needs of the population. The authors present a model in which state population data and nursing resource data are compared with national data to assist state planning groups in developing an effective workforce management plan. Integrating population demographic data, healthcare needs of citizens, and nurse resource factors at the state level can improve the accuracy of projection statistics.
Adult↗
Impact of antidiabetic medications on physical and cognitive functioning of older Mexican Americans with diabetes mellitus: a population-based cohort study.
PURPOSE: The current study was designed to evaluate the utility of antidiabetic medications in affecting changes in physical and cognitive functioning among older Mexican Americans with diabetes over a 2-year period. METHODS: A longitudinal analysis with repeated measurements between 1999 and 2001 was performed in a cohort of Mexican Americans, 60 or older, in the SALSA Project. Statistical analysis was conducted using a generalized estimating equation. RESULTS: For subjects with diagnosed diabetes </= 5 years (N = 381), there was less decline in physical and cognitive functioning over 2 years among subjects on treatment, compared to those without treatment. For subjects with diagnosed diabetes of 5+ years (N = 337), the effect of antidiabetic medications was more significant in preventing the decline in physical and cognitive functioning (ADL: mean in log scale = -0.10, 95% CI = -0.16, -0.04, 3MS: mean = 6.35, 95% CI = 3.23, 9.48). Combination therapy of antidiabetic agents appeared to be more effective than monotherapy in preventing the decline in physical and cognitive functioning for subjects. CONCLUSIONS: Antidiabetic drugs appear to be useful in alleviating the decline in physical and cognitive functioning among older Mexican Americans with diabetes, especially for those with a longer duration of the disease.
Activities of Daily Living↗
Ethical wills and suffering in patients with cancer: a pilot study.
INTRODUCTION: Suffering at the end of life may be caused by many factors, including pain and other symptoms, concern about family and friends, and loss of control of one's life. Several authors have suggested that loss of meaning is pivotal in suffering. An ethical will (EW) is a statement, usually written, capturing one's values, wisdom, hopes, and advice. EWs have been suggested as a vehicle for finding meaning as the end of life approaches. This pilot study of EWs examined methods for exploring the role of EWs in reducing suffering at the end of life. METHODS: Oncology clinic patients 65+ years of age in active therapy for cancer were randomly assigned to one of two arms: EW or control. Subjects in both arms had writing assignments, three home visits, and exit interviews. Suffering was measured at baseline and at the time of the exit interview, using a series of Likert-like scales. RESULTS: Twenty-four subjects (10 EW and 14 control) completed the study. Among EW subjects, trends toward reduced suffering were noted in "concern for loved ones," "unfinished business," and "fear of the future." Several methodological issues were identified by this pilot study, including selection of population for studying suffering, placebo effect, and randomization. CONCLUSIONS: EW may be valuable in alleviating suffering; a larger study will be needed to examine efficacy. The study of interventions designed to reduce suffering at the end of life requires careful attention to the definition and measurement of suffering, study design, and subject selection.
Adaptation, Psychological↗
Translating best practices in nondrug postoperative pain management.
BACKGROUND: The research-to-practice gap is at the heart of the problem in the underuse of nondrug complementary methods to manage postoperative pain. PURPOSE: To show how the six steps of the Collaborative Research Utilization (CRU) model can be used to translate research into practice, using an example of nondrug pain management protocols. METHODS: The CRU model was used to translate empirically tested nondrug interventions for surgical pain management enhancement into cost-effective, easy-to-use, best-practice nursing interventions, using tailored patient teaching. RESULTS: The preliminary findings of the substudy in the context of the CRU model are reported. DISCUSSION: The CRU model was successful in changing patients' knowledge, attitudes, and use of nondrug interventions for pain management. Further research is needed in heterogeneous populations. Organization receptivity to research and a well-integrated computerized documentation system for cueing clinicians' pain management practices are key for effectiveness of change.
Aged↗
Prophylaxis against early adrenal insufficiency to prevent chronic lung disease in premature infants.
UNLABELLED: BACKGROUND. Many extremely low birth weight infants (<1000 g) show biochemical evidence of adrenal insufficiency in the first week of life, correlating with subsequent development of chronic lung disease (CLD). METHODS: We conducted a randomized, double-masked, placebo-controlled pilot study to test whether early treatment with low-dose hydrocortisone for 12 days (1 mg/kg/day for 9 days followed by.5 mg/kg/day for 3 days), begun before 48 hours of life, would increase the likelihood of survival without CLD. RESULTS: Forty patients were enrolled at two centers. Birth weight and gestation were similar for treatment and placebo groups: 732 +/- 135 g versus 770 +/- 135 g and 25.2 +/- 1.3 weeks versus 25.4 +/- 1.5 weeks. More infants treated with hydrocortisone achieved study success, defined as survival without supplemental oxygen at 36 weeks' postconception (12/20 [60%] vs 7/20 [35%]). Lower birth weight, histologic chorioamnionitis, and preeclampsia were significant risk factors, whereas study center, prenatal steroids, sex, and ethnicity were not significant. Hydrocortisone treatment decreased days on >40% oxygen, days on >25% oxygen, days on ventilator, and oxygen at discharge. Among infants exposed to chorioamnionitis, hydrocortisone treatment also was associated with increased enteral intake during the first month of life and with increased weight at 36 weeks' postconception. Five treated infants and 6 placebo infants developed sepsis; 3 in each group died. CONCLUSIONS: First, early treatment with low-dose hydrocortisone in this population of extremely low birth weight infants increased the likelihood of survival without CLD. Second, the benefit was particularly apparent in infants with chorioamnionitis. Third, a larger multicenter trial is needed to verify the primary outcome and to better evaluate risks and benefits.
Adrenal Insufficiency↗
Reactivity of peripheral blood lymphocytes to oxidized low-density lipoprotein: a novel system to estimate atherosclerosis employing the Cellscan.
BACKGROUND: The assumption that atherosclerosis involves an autoimmune response to oxidized LDL (oxLDL) is based on the presence of immunocompetent cells and immunoglobulin deposition in the atherosclerotic lesions by successful immunomodulation of the atherosclerotic process and by inhibition of experimental atherosclerosis by antioxidants. The Cellscan system is a multiparameter laser-based static cytometer that enables repeated monitoring of the fluorescence intensity (FI) and polarization (FP) of individual living cells. Analysis of intracellular fluorescein fluorescence polarization (IFFP) has previously been used to define activated lymphocyte population. HYPOTHESIS: In this study, the Cellscan apparatus has been used to monitor cellular response to oxLDL in patients with atherosclerosis and in controls. METHODS: The FI and FP of fluorescein diacetate (FDA)-labeled peripheral lymphocytes were measured following exposure to oxLDL in vitro. Using cluster analysis we were able to identify subpopulations of cells that were characterized by their FI and FP. Forty-two subjects were studied: 22 patients with severe coronary heart disease and 22 control individuals, either healthy or with other diseases. RESULTS: Fluorescence intensity of fluorescein-labeled peripheral blood lymphocytes (PBL) was markedly decreased upon exposure to high doses (> 25 micrograms/ml) of oxLDL concurrently with an increase in FP. A specific and dose-dependent reduction in FP of the high-intensity cell subpopulations, accompanied by higher FI, was evident in patients with ischemic heart disease upon exposure to low doses of oxLDL (up to 25 micrograms/ml). Maximal depolarization was shown upon triggering with 2 micrograms/ml oxLDL. The polarization ratio (the mean polarization value of the specific cell population with and without activation) obtained for patients' lymphocytes was significantly lower (p < 0.01) than that of the control group (0.936 +/- 0.05 and 1.028 +/- 0.055, respectively). CONCLUSION: These data suggest that PBL from patients with active ischemic heart disease show an increased reactivity to oxLDL. A 73% positivity rate was found for ischemic heart disease patients compared with 5% in the control subjects. One of the future prospects of this study might be the advent of a simple and rapid noninvasive test that could assess the extent of atherosclerosis, and possibly even the response to therapy, by monitoring the reactivity of PBL to oxLDL.
Aged↗
Involvement of family and community medicine professionals in community projects.
OBJECTIVE: Medical schools are being challenged to continue their excellence in education, research, and patient care while responding to the health needs of the public. The objective of our study was to determine the nature and type of community involvement of professionals in departments of family and community medicine. STUDY DESIGN: We mailed a 24-item structured survey to a random national sample of family medicine professionals. POPULATION: Survey recipients included 770 full-time physician and nonphysician active members of the Society of Teachers of Family Medicine. OUTCOMES MEASURED: Our survey assessed community activities, challenges and incentives to those activities, and desired resources for working in the community. RESULTS: A total of 446 usable surveys were returned (58% response rate). Ninety-five percent of respondents had participated in a community activity within the previous year. More male respondents precepted medical students or residents and educated faculty on topics regarding community education; more older respondents participated by sitting on community health boards or councils. Insufficient release time and lack of funding were the 2 most frequently cited barriers to community-based activities. CONCLUSIONS: Most faculty are involved in community-related teaching and service. Reasons for low levels of research and subgroup differences, especially among women and young faculty, merit further research.
Academic Medical Centers↗
An open-label, dose escalation pilot study of the effect of clonazepam in burning mouth syndrome.
OBJECTIVE: Current treatment for burning mouth syndrome is usually directed at correction of detected organic causes or is empiric, and it often involves the use of tricyclic antidepressants. Recently, there has been renewed interest in the use of benzodiazepines for burning mouth syndrome. The present study was designed to assess the effect of clonazepam in burning mouth syndrome. STUDY DESIGN: Thirty patients, each with a chief complaint of mouth burning without oral mucosal lesions, were entered into the study. All patients underwent routine blood screens. Identified abnormalities were corrected, when possible, before clonazepam was prescribed. The starting dose was 0.25 mg daily, with an increase in dose of 0.25 mg on a weekly basis if symptoms continued. RESULTS: The subject population consisted of 29 women and 1 man. All subjects had been symptomatic (average premorbid burning intensity, 7.0 +/- 1.9 on 10-point scale) for 1 month to 12 years (mean, 3.9 +/- 3.4 years; median, 2.75 years), and 16% had had burning for more than 2 years. Three groups of patients were identified: those who experienced partial to complete relief with clonazepam and who were using the medication at the last follow-up (group 1; 43%); those who found the clonazepam helpful but withdrew from the medication because of side effects--usually drowsiness (group 2; 27%); and those who did not benefit from clonazepam (group 3; 30%). Among the 3 groups, age was found to be significantly lower for group 1 than for group 2 but not significantly lower for group 1 than for group 3. Although the difference did not reach significance, the mean dose of clonazepam appeared lower for group 1 patients than for the other 2 patient groups. The number of patients with burning for less than 2 years was larger in group 1 than in the other groups. CONCLUSIONS: The results suggest that clonazepam may be helpful in burning mouth syndrome, inasmuch as 70% of patients (groups 1 and 2) experienced pain reduction with effects at low doses. These findings suggest that the mechanism of action of clonazepam may be specific and separate from the anxiolytic effect of the benzodiazepines and that clonazepam may represent a useful therapy in a subset of patients with burning mouth syndrome. Double-blind, placebo-controlled trials are warranted.
Aged↗
Comparison of condylar guidance setting obtained from a wax record versus an extraoral tracing: a pilot study.
STATEMENT OF PROBLEM: Protrusive condylar angles can be determined by use of wax protrusive records (WPR), pantographic tracings (PT), and occlusal wear facets. These methods generate different angles in the same patient. PURPOSE: The purpose of this study was to compare the condylar inclination angles found by use of the WPR in a Hanau articulator with those found by use of the Whip-Mix PT quick-set recorder. The occlusal wear facet method was not part of this study. MATERIAL AND METHODS: Ten subjects were chosen at random from a dental school patient population. All subjects had a majority of maxillary and mandibular teeth present and according to the examination criteria used in the school's Division of Occlusion, they were healthy with no signs/symptoms of temporomandibular disorders. The WPR was accepted when it was evident that the patient had protruded straight forward at least 6 mm anterior to centric relation, as shown on the Hanau articulator by the condylar spheres having moved anteriorly an equal distance of 6 mm on both sides. The condylar inclination on the articulator was adjusted accordingly. The PT was used according to the manufacturer's directions, which included the use of an intraoral clutch adapted to the mandibular arch, connected to an extraoral facebow with bilateral inscribing pointers. A holder frame was adapted to the face with bilateral flags where the inscribing pointers traced the protrusive movement of the jaw. All the readings were in degrees. No control was used in this project. To test whether there was a significant difference between the 2 independent samples, a Mann-Whitney U test was performed (P=.01). RESULTS: The mean results for the WPR were as follow: right side (28.1 degrees, SD 8.94); left side (31.50 degrees, SD 9.73). For the PT, results were: right side (41.10 degrees, SD 7.53); left side (35.5 degrees, SD 6.43). When right and left side protrusive condylar angles were combined, the values were: WPR (29.80 degrees, SD 9.25); PT (38.30 degrees, SD 6.98). The differences on the right condylar values were significant (P=.01). There was no statistical difference on the left side. CONCLUSIONS: Within the limitations of this study, it was concluded that the PT technique yielded greater values for the protrusive condylar inclination than the WPR.
Centric Relation↗
Physical therapy manpower planning. Projection models and scenarios of 1985.
Faced with the difficult task of coordinating statewide health education, the Kentucky Council on Higher Education is using several manpower projection statistics as one component of their decision-making process. These manpower data are essential when considering the establishment, expansion, continuation, or termination of health-related academic programs. Three models were used to project manpower requirements for licensed physical therapists in Kentucky. The models were 1) manpower:population ratio, 2) trend analysis based on time series, and 3) the American Physical Therapy Association's health-needs method. Four variants of the manpower:population ratio model are discussed and presented: population ratio based ona 1) national ratio, 2) Kentucky ratio, 3) weighted national ratio, and 4) weighted Kentucky radio. The trend analysis model is presented and discussed. The health-needs approach, based on expert opinion and health-related variables, identifies the quantity and quality of services required to provide the Kentucky population with the best possible care. The paper concludes with three brief scenarios describing the possible effects of the three models and physical therapy in Kentucky. The scenarios unfold from differing assumption about the effects of manpower production on health care. Scenario A is a "current arrangement" scenario. Scenario B considers the effects of predicting future manpower requirements and resources based on the past. Scenario C projects the effects of a comprehensive plan on the goal of producing the best possible care for all Kentuckians.
Forecasting↗
Utilization of evidence-based teaching in U.S. dental hygiene curricula.
PURPOSE: The purpose of this research was to survey U.S. dental hygiene program directors to determine: (1) demographic information, (2) specific Evidence-Based (EB) student instruction methods used, (3) if and how programs use an EB philosophy, (4) perceptions of faculty skills in incorporating EB instruction, and (5) opinions and attitudes regarding future need to incorporate EB philosophies in dental hygiene education. METHODS: Data were gathered by surveying all 235 United States dental hygiene program directors in 1999. The survey included 20 closed items and 1 open-ended item. Initially, the survey was pilot tested using a convenience sample of seven U.S. dental hygiene program directors. A final, revised survey was mailed to the cohort population. A response rate of 70% (n = 164) was achieved after two mailings, and responses were analyzed using descriptive statistics. RESULTS: The demographic results of this study revealed the majority of respondents were from associate degree/certificate dental hygiene programs (77%). Results revealed that most dental hygiene programs are beginning to include some fundamental EB concepts and skills into their curriculum, primarily by incorporating analysis of scientific literature. Most programs provide students with formal library orientation (88%), instruct students in the use of library indices or library databases (86%), and teach the use of the Internet for conducting literature searches (79%). Respondents indicated the major barriers for fully incorporating an EB approach in their dental hygiene program were: lack of faculty skills (37%), no available time (34%), lack of financial resources (33%), and lack of technical support (28%). CONCLUSION: Findings of this study suggest dental hygiene educators have made small strides in creating an EB philosophy dental hygiene curriculum. However, the future of dental hygiene education must address the need for faculty development and training in areas such as computer utilization in core dental hygiene courses, strategies to improve the curriculum to stimulate students' critical thinking skills, and to develop educators' skills in the use of evidence for clinical decision-making.
Attitude of Health Personnel↗
[Meta-analysis of the Italian studies on short-term effects of air pollution].
BACKGROUND: In recent years, much attention has been given to review reports on the early effects of air pollution on health, measured through daily series of deaths and/or hospital admissions. A number of large planned meta-analyses (in which methods for data retrieval and processing are commonly planned a priori for all participating centers) are on going both in the US and in Europe. The National Mortality, Morbidity and Air Pollution Study included data from 90 US cities, whereas APHEA (Air Pollution and Health, a European Approach) considers data from about 30 european cities. The present paper summarizes methods and findings of MISA, a meta-analysis of data from 8 Italian cities. It belongs to an ad hoc supplement of Epidemiologia & Prevenzione (Epidemiol Prev 2001; 25 (2) Suppl: 1-72), the official Journal of the Italian Association of Epidemiology, which contains a full description of the study. MISA was launched on March 2000, within the project "Statistics, Environment and Health" (GRASPA), funded by the Italian Ministry of Education. Additional support was given by the Authorities of the 8 participating cities (from North to South: Turin, Milan, Verona, Ravenna, Bologna, Florence, Rome and Palermo). DAILY HEALTH DATA: Deaths certificate and hospital admission data have been collected respectively from the Local Health Authority and regional files. The same programme for retrieval of data on selected hospital admissions for acute conditions was used in the 8 cities. Main data are summarized in Table 1. DAILY CONCENTRATION OF POLLUTANTS: Most data were obtained from Regional Environmental Protection Agencies, which are responsible for environmental monitoring since 1993. Verona, Palermo and Milan (1990-94) data were obtained from local sources. Monitors with more than 25% of missing data were excluded. Meteorological data were collected by the same monitors and completed with data from monitors situated in the suburbs or (in Milan and Bologna) in the airport. The monitors were selected by a group of experts to ensure comparability. For SO2 and NO2 daily averages of hourly measurements were used, whereas concentrations of ozone and CO were estimated as the maximum 8 hours moving average. Total suspended particulate or PM10 were measured as 24 hours deposition. All analyses used the whole range of observed values (Table 2). Daily data were considered as missing when more than 25% of hourly data were not available. Missing data in one monitor were imputed as average of data from the remaining monitors weighted by the ratio between the specific monitor's year average and the general year average of all the selected city monitors. Missing data in one day were imputed as average of four days (preceding and following day, the same day of the previous and following weeks). In the city of Florence and Palermo PM10 concentrations were available. For the other cities we applied a conversion factor from PTS to PM10 (0.6 for Turin and 0.8 for all the others) estimated through validation studies. Ozone concentrations were used only where background monitors were available (Turin, Verona, Bologna and Florence) and limited to the warm season (May through September). METHODS: A common protocol for the city-specific analyses was defined on the basis of a structured exploratory analysis. The adopted basic model was a Generalized Additive Model for Poisson data. Effect estimates were age-adjusted (0-64, 65-74, 75+) and formal tests of interaction pollutant-age were conducted. In the first two age groups, indicator variables for seasonality were specified, and cubic splines with fixed number of degree of freedom were specified for the last age group and for all age groups for the morbidity data. Model adequacy was checked by residual analysis and inspection of the partial autocorrelation function. In a sensitivity analysis non linear pollutant effects were considered and overdispersed [table: see text] transitional models were fitted; the analysis was conducted for all lags 0-3 and some distributed lags (0-1, 1-2, 0-3); no multipollutant models were fitted. The same model was fitted to the city data. No model selection was done: Table 3 describes the steps in model building. In the meta-analysis, for each outcome, the estimates for each pollutant and for each city were combined using fixed and random effects models. Heterogeneity of effects was tested according to DerSimonian and Laird. Results were checked using a hierarchical bayesian model, which was used to investigate heterogeneity across cities in a meta-regression phase. Non informative priors were used. Posterior distributions of parameters of interest have been obtained with WinBUGS. 10,000 iterations (excluding [table: see text] the first 2000) were retained, while for the meta-regression 100,000 iterations (excluding the first 4000) were stored. To approximate the marginal posteriors only one sample out of five were used. Achieved convergence was assessed using the Gelman and Rubin approach. In the meta-regression the models specified were the following: [formula: see text] i denotes city, j calendar period (1990-1994; 1995-1999). The first model includes only period as effect modifier, while the second model other potential variables. The ui terms (which do not vary with j) represent city specific random effects. RESULTS: For each pollutant, the meta-analysis detected a statistically significant association with mortality for natural causes. But for ozone, positive associations were commonly found for death and hospital admissions for both cardiovascular and respiratory diseases. Indeed, the only estimates whose lower 95% confidence limit bore a negative sign regarded the association between PM10 and mortality from respiratory diseases. Ozone in the warm season was positively and significantly associated with daily mortality and mortality for cardiovascular diseases whereas other estimates did not reach statistical significance and some were negative (only lag 0-1 for external comparability are reported in Table 4). Risks were highest (up to 4%) for respiratory conditions (Table 4). They were more pronounced at lag 1-2 for mortality, and at lag 0-3 for hospital admissions. Age was an effect modifier for mortality, the elderly being more susceptible. In the random effect meta-analysis, at lag 1-2, excess risks for unit increase of the pollutants at age 75+ and at age 0-64 were respectively: 4.9% and -0.4% for SO2, 1.7% and 0.6% for NO2; 2.3% and 0.2% for CO. Corresponding figures for PM10 at lag 0-1 were 1.1% and 0.2%. The effect of PM10 on mortality [table: see text] was greater during the warm season (2.8% vs 0.8%). A complete analysis is reported in the Italian text. Here we provide some details on the effects of PM10, about which the residual heterogeneity across cities was highest (Table 4). In addition, the epidemiological evidence on the hazards from this fraction of particulate matter is more controversial. Table 5 reports the excess risk estimated through the meta-analysis in 1995-99 for a 10 micrograms/m3 increase of PM10 for some outcomes. Proper prior distributions (overdispersed normal and inverse gamma) were adopted in the final bayesian analyses. The sensitivity of results to the choice of the priors were investigated (we defined proper and improper uniform, student's t), obtaining comparable results. Total natural mortality was significantly heterogeneous across cities (Q = 18.96, 5 df, p < 0.001). City-specific estimates are represented graphically in Fig. 1. As expected, the confidence (credibility) intervals are widest [table: see text] for bayesian estimates, intermediate for those obtained under a random effects model, and narrowest for those found under a fixed effects model. Nevertheless, differences in point estimates are negligible. A North-South gradient in risk is obvious. Table 6 shows, for the cities for which mortality data were available, the improvement in precision and the shrinkage of effect estimates toward the overall mean introduced by the bayesian modelling. In the meta-regression, total mortality and a deprivation score were associated with greater effects. The excess risks on hospital admission were modified by the deprivation score and by the NO2/PM10 ratio. Overall, the risk estimates were greater in the calendar period 1995-99 and there was a North-South gradient, with larger effects in cities located in Central and Southern Italy (Florence, Rome, Palermo). CONCLUSIONS: The meta-analysis of the Italian studies on short-term effects of air pollution in 8 cities, MISA, exhibits the following features: With the exception of Naples, all greatest Italian cities were included; overall a population of 7 million was enrolled. The study protocol was accurate with regard to the selection of hospital admissions for acute conditions. Monitored data of concentration of pollutant were carefully evaluated before their inclusion in the meta-analysis. City specific analyses were carried out according to a common protocol controlling for seasonality, influenza epidemics, age and meterological variables; [table: see text] the protocol derived from a structured exploratory analysis. The meta-analysis was done using fixed and random effects models; a hierarchical bayesian model was fitted in a sensitivity analysis. The heterogeneity of effects across cities was investigated using a hierarchical bayesian model for meta-regression. While mortality data are of good quality, hospital admission data are more problematic. Since the filing criteria for the latter changed around 1995, comparability of results before and after such date is limited. Moreover, hospital admissions rely on availability of beds, the offer of which may be restricted during the warm season. Comparability of pollutant concentration estimates among cities may have been influenced by differences in monitor characteristics. (ABSTRACT TRUNCATED)
Adolescent↗