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Determinants of health status and the influence of primary health care services in Latin America, 1990-98.

Primary health care (PHC) services have been advocated as a means by which less developed countries may improve the health of their populations even in the face of poverty, low levels of literacy, poor nutrition and other factors that negatively influence health status. Using aggregated data from the World Bank and UNICEF this study examined which factors, both within the health care system and outside of it, are associated with under-5 mortality rates in 22 countries of Latin America and the Caribbean during the 1990s. In a multivariate analysis using generalized estimating equations for repeated measures, five factors were found to be independent predictors of lower under-5 mortality rates (U5MRs). These were vaccination levels, female literacy, the use of oral rehydration therapy, access to safe water and GNP per capita. When the magnitude of these associations were assessed, higher levels of GNP per capita was found to be very weakly associated with lower U5MRs, compared with female literacy and vaccination rates. These findings suggest that government policies which focus only on promoting economic growth, while not making important investments in PHC services, female education and access to safe water are unlikely to see large improvements in health status.

Adolescent↗

Geographic differences in invasive and in situ breast cancer incidence according to precise geographic coordinates, Connecticut, 1991-95.

To evaluate geographical variation of invasive and in situ breast cancer incidence rates using precise geographical coordinates for place of residence at diagnosis, latitude-longitude coordinates pertaining to 10,601 invasive and 1,814 in situ breast cancers for Connecticut women, 1991-95, were linked to US Census information on the 2,905 State census block groups. A spatial scan statistic was used to detect geographic excess or deficits in incidence and test the statistical significance of results, without prior assumptions about the size or location of such areas. The age adjusted invasive cancer incidence rate was 165.3/100,000 women/year. The spatial scan statistic identified 3 places with significantly low incidence rates and 4 places where rates were significantly high. The most probable location of low incidence was rural northeastern Connecticut where risk of disease, relative to elsewhere around the state, was 0.70 (p = 0.0001); the most probable place of elevated incidence was north central Connecticut where a relative risk of 1.34 (p = 0.002) was observed. Incidence of in situ disease was estimated to be significantly high for north central Connecticut (RR = 1.84; p = 0.0001). Geographic differences of invasive and in situ breast cancer incidence were observed. Examining cancer events at the lowest available level of data aggregation is beneficial in highlighting localized rate variations. Such information may enable public health officials to target additional resources for promoting breast cancer screening to specific locations.

Adult↗

Mutagenicity of textile dye products.

Within an EU-funded research project, 281 textile dye products in use at nine textile finishing companies from eight European countries were assessed for potential mutagenic properties. Most of the dyes belonged to the so-called existing substances. Data sources considered were data published in the literature, unpublished industrial data provided by dye producing companies, and laboratory testing. Data on mutagenicity are virtually absent for many of the dyes. Unpublished test results performed on behalf of the dye manufacturing industry proved to be an important data source that is not accessible under usual circumstances. Four dye stuffs contained in seven dye products in use at the textile finishing companies were judged to be mutagenic, based on published data from the literature. Mutagenicity testing using Salmonella typhimurium, strains TA98 and TA100, revealed positive results for about 28% (15 out of 53) of the dye products investigated. Upon further testing with the mouse lymphoma assay (L5178Y/TK(+/-)) 67% (6 out of 9) of Ames-positive dyes proved to be mutagenic in this mammalian cell test. All data sources combined led to an overall assessment of 14 dye products out of 281 being mutagenic. For 16 there is a suspicion of mutagenicity due to positive responses in one test but 71 of the dye products are without any data on mutagenicity. This paper describes the data aggregation process, evaluation criteria and the overall assessment, and exemplifies controversial evaluations.

Animals↗

Effect of tumor necrosis factor-alpha and interferon-gamma on the growth of a human salivary gland cell line.

Interferon-gamma (IFN-gamma) is a product of activated T-lymphocytes, and tumor necrosis factor-alpha (TNF-alpha) is a product of both lymphocytes and macrophages. These cell types are often present at sites of tissue damage secondary to chronic infection or autoimmune disease. The purpose of this study was to characterize the effects of TNF-alpha and IFN-gamma on a human submandibular gland epithelial cell line (HSG). IFN-gamma caused a concentration-dependent decrease in HSG cell growth (approximately 70% in 6 days). Conversely, TNF-alpha alone had little effect on the growth of these cells. When these cytokines were added in combination (20 units/ml TNF-alpha and 1,000 units/ml of IFN-gamma), there was a synergistic antiproliferative effect; no apparent cell growth was observed. The cytokine-induced antiproliferative effect was reversible. After the apparent cessation of cell growth for 3-6 days, removal of the cytokines permitted complete growth recovery. Further, cells that recovered and exhibited growth patterns that were similar to control cells remained susceptible to the antiproliferative effects of the cytokines. Flow cytometry revealed that the percentage of cells in G0/G1 with the combination of cytokines was significantly increased by 24 h. The antiproliferative effect of IFN-gamma alone and that of IFN-gamma and TNF-alpha in combination were blocked completely using an antibody to the IFN-gamma receptor. A hypothesized mechanism of tissue damage in autoimmune inflammatory disorders is via up-regulation of cell surface markers such as intercellular adhesion molecule type I (ICAM-1) and histocompatibility antigen HLA-DR which can exacerbate the inflammatory process. Treatment of HSG cells with IFN-gamma, with or without TNF-alpha, resulted in increased levels of ICAM-1 and the acquisition of HLA-DR expression. These aggregate data suggest that IFN-gamma alone can regulate the expression of cell surface markers involved in the inflammatory process as well as cause a potent yet reversible inhibition of HSG cell growth that is modulated by the presence of TNF-alpha.

Antibodies↗

Evidence for the presence of a Hg-inhibitable water-permeability pathway and aquaporin 1 in A5 salivary epithelial cells.

The molecular basis of water-permeability in salivary and other exocrine glands is not understood. We have examined two well-studied salivary epithelial cell lines for evidence of a Hg-inhibitable water-permeability pathway. A5 and HSG cells are derived from rat and human submandibular glands, respectively. Only A5 cells demonstrated such a pathway. The rate of A5 cell osmotic shrinkage was inhibited about fivefold in the presence of 300 microM HgCl2. To determine if this activity was associated with the expression of the prototypical water channel (aquaporin, AQP) AQP1, we used three separate experimental approaches; Northern analysis and reverse transcription-polymerase chain reaction (RT-PCR) analysis of isolated mRNA, and Western analysis of cell membranes. All three methods yielded positive results with A5 cells and negative results with HSG cells. The approximately 800 bp product of RT-PCR was analyzed further by sequencing and restriction enzyme digestion. The results were consistent with the previously reported coding region sequence for rat kidney AQP1. The aggregate data demonstrate that marked differences in water-permeability and water channel expression exist in these two salivary epithelial cell lines.

Animals↗

A review of multilevel theory for ecologic analyses.

This paper reviews multilevel and conventional models for the analysis of ecologic (group, aggregate) data. It emphasizes the non-separability of contextual (group-level) effects and individual-level effects that arises from the multilevel structure of the underlying effects. Contrary to common misperceptions, this problem afflicts ecologic studies in which the sole objective is to estimate contextual effects, as well as studies in which the objective is to estimate individual effects. Multilevel effects also severely complicate causal interpretations of model coefficients.

Bias↗

Variation in heart disease mortality across census tracts as a function of overdispersion and social class mixture.

Variation in heart disease (HD) mortality rates across census tracts is greater than expected given binomial error and available explanatory variables. We extended an extra-binomial variation model for rates standardized by the direct method. The overdispersion parameter accounted for 36 per cent of the observed variation in standardized rates. Ignoring overdispersion resulted in a change in an estimate of the effect of social class on HD mortality and substantial underestimation of the error of the estimates of such effects. Ecologic regression on the proportional mixture of social classes within tracts provided an appealing approach to the problem of estimating fixed effects with aggregated data.

Adolescent↗

Spatial disease clusters: detection and inference.

We present a new method of detection and inference for spatial clusters of a disease. To avoid ad hoc procedures to test for clustering, we have a clearly defined alternative hypothesis and our test statistic is based on the likelihood ratio. The proposed test can detect clusters of any size, located anywhere in the study region. It is not restricted to clusters that conform to predefined administrative or political borders. The test can be used for spatially aggregated data as well as when exact geographic co-ordinates are known for each individual. We illustrate the method on a data set describing the occurrence of leukaemia in Upstate New York.

Cluster Analysis↗

Resolution of phylogenetic relationships among recently evolved species as a function of amount of DNA sequence: an empirical study based on woodpeckers (Aves: Picidae).

Synonymous substitutions in the 13 mitochondrial encoded protein genes form a large pool of characters that should approach the ideal for phylogenetic analysis of being independently and identically distributed. Pooling sequences from multiple mitochondrial protein-coding genes should result in statistically more powerful estimates of relationships among species that diverged sufficiently recently that most nucleotide substitutions are synonymous. Cytochrome oxidase I (COI) was sequenced for woodpecker species for which cytochrome b (cyt b) sequences were available. A pairing-design test based on the normal distribution indicated that cyt b evolves more rapidly than COI when all nucleotides are compared but their rates are equal for synonymous substitutions. Nearly all of the phylogenetically informative substitutions among woodpeckers are synonymous. Statistical support for relationships, as measured by bootstrap proportions, increased as the number of nucleotides increased from 1047 (cyt b) to 1512 (COI) to 2559 nucleotides (aggregate data set). Pseudo-bootstrap replicates showed the same trend and increasing the amount of sequence beyond the actual length of 2559 nucleotides to 5120 (2x) resulted in stronger bootstrap support, even though the amount of phylogenetic information was the same. However, the amount of sequence required to resolve an internode depends on the length of the internode and its depth in the phylogeny.

Animals↗

Missense mutations and the magnitude of functional deficit: the example of factor IX.

Some missense changes are compatible with normal protein function while others compromise essential aspects of protein maturation, specific activity, or stability. For those missense changes that alter function in the intact organism, how likely is it for the mutated protein to retain appreciable residual activity? By genetic analysis of patients with hemophilia B of known severity, this question can be addressed for missense mutations that reduce factor IX activity by fourfold or more below the average. We estimate that missense changes cause only 59% of moderate and severe disease, but these mutations are almost always (95%) of independent origin. In contrast, missense mutations are found in virtually all (97%) families with mild disease, but only a minority of these (41%) are of independent origin. From the aggregate data, we estimate that most (71%) of the independent deleterious missense mutations cause at least a 20-fold decrease in factor IX activity.

Factor IX↗

Aminolevulinate dehydratase and blood lead levels in urban male adults.

The existence of an association between aminolevulinic acid dehydratase activity in erythrocytes (ALA-d) and blood lead level (Pb-B) has been investigated in a male urban population not occupationally exposed to lead. The data show a decrease of the mean ALA-d activity when Pb-B rises but the association is not statistically ascertained in every case when the data are examined by two different procedures. It appears first that the statistical significance depends on an adequate choice of the distribution function of the ALA-d. Secondly, factors such as interindividual variability of this biological index, lack of precision in the analytical measurements of the Pb-B and the range of the environmental exposure under observation may influence the statistical significance and induce misleading statements. The data aggregation allows the avoidance of some inconsistencies. Furthermore, the estimation of mean ALA-d for the different Pb-B may also be biased by confounding risk factors (such as smoking habits). As such factors are not presently taken into consideration in public health surveys, the no-threshold Pb-B hypothesis, suggested by the observed dose-effect relationship, cannot be strongly supported.

Adult↗

The effect of religion on suicide ideation.

Work on the impact of religion on suicide has not yielded consistent results. Classic Durkheimian models stressing religious affiliation (Catholic vs Protestant) have been questioned in recent years and some authors have argued for a model based on the alternative conception of religious commitment (e.g. religiosity per se) as a prophylactic against suicide. Almost all of this work has been based on highly aggregated data where it is not known if nonreligious people account for the suicides. The present study tests both models with national data on 1,687 respondents. No support is found for the Durkheimian model at the individual level, but some is found for the religious commitment model: the greater the church attendance the lower the approval of suicide. The effect of religiosity on suicide ideation is independent of education, gender, marital status, and age.

Humans↗

Female labour force activity and the sex differential in mortality: comparisons across developed nations, 1950-1980.

This paper examines the macro-level relationship between female labor force activity and the sex differential in mortality among developed nations. Discrimination, protection, and null relationship hypotheses are tested using aggregate data for 18 high income nations over 7 time points from 1950 to 1980. High levels of female labor force activity--controlling for a variety of general social conditions--increase the longevity advantage women have over men. In some models the effects are immediate; in other models the effects occur after a substantial lag; but in no cases are there harmful effects for women's longevity. Also important for the differential are consumption of cigarettes and alcohol, and the level of income inequality in a society.

Alcohol Drinking↗

Providing antenatal services in a primary health care system.

A study sample of 880 women attending the primary health care center in the Al-Baha region of Saudi Arabia was interviewed on their attitudes towards antenatal care services in the primary care setting. Some 91.3% of the women expressed positive views about obtaining the antenatal care in these centers. The major factor influencing their choice was the geographic location of primary health centers which are near to their residence and therefore more convenient for them to patronize. Other factors were the easier access to staff in primary care centers, especially mid-wives and female doctors. There was a significant relationship of age, parity and education with their current antenatal and delivery practices. The women also recommended less than ten antenatal visits before delivery. These findings are relevant to any policy regarding maternity services in the country.

Adolescent↗

[Predictors for ambulatory medical care utilization in Germany].

An analysis of the possible influences on primary health care utilization is made. The theoretical framework is the health behavioural model of R. M. Andersen, dividing the influencing variables into the components predisposing characteristics, enabling resources, and need factors. The study was based on data from the German National Health Examination and Interview Survey of the adult population in 1998. The data were linked to regional structural data and aggregated account data. The total number of contacts, the number of contacts with general practitioners and internists, and the number of different specialists contacted in the last 12 months, as calculated from interview data, were used to indicate primary health care utilization. In addition to the expected strong influence of need factors such as morbidity and health-related quality of life, the predisposing characteristics such as region, urban/rural, age, and gender have a significant influence on the primary care utilization. With regard to the enabling factors, persons with a family doctor had more contacts overall, which contrasts with the family doctor's assumed gate-keeper function. From the results of the study, recommendations on possible regulatory measures are given, but also some restrictions for influencing the number of contacts are pointed out.

Adult↗

[Effects of tobacco tax increase on cigarette consumption and the impact on health policy].

The purpose of this study is to analyse the recent development of tobacco taxes and demand for cigarettes in Germany and to describe consequences for health policy. A descriptive analysis of aggregated data of the Federal Statistical Office is used to show the development of tax income and consumer behaviour with regard to the degree of substitution between differently taxed tobacco products. From 1993 to 2002 the demand for cigarettes increased nearly continuously. In 2003 the demand for industrial cigarettes went down by 8.6% and in 2004 by 15.8%. The difference between taxes and prices of industrial cigarettes and substitutes increased over the time period and still continues to increase. Tax and price differences between tobacco products led to partial compensation of the decreasing demand for industrial cigarettes. Therefore a tax increase on substitute products like fine cut tobacco is recommended. There is still a lack of longitudinal epidemiological data on smoking behaviour in Germany that could affirm effects of tobacco taxation.

Germany↗

Cardiovascular drug utilisation and socio-economic inequalities in 20 districts of the Czech Republic.

OBJECTIVE: To analyse whether there exists a socio-economic gradient in utilisation of cardiovascular drugs at the district level in the Czech Republic. METHODS: The aggregated data on drug utilisation during the period 1997-2000, expressed in defined daily doses per 1000 inhabitants per day, were obtained from the General Health Insurance Company. Socio-economic characteristics of the districts in year 2000 (percentage of university-educated inhabitants, percentage of single-member households, number of ambulatory physicians per 10,000 inhabitants, unemployment rate and mean monthly income) were used as single unadjusted predictor variables. Partial correlation controlling for age in districts was used to analyse the relationship of cardiovascular disease (CVD) drug utilisation and several socio-economic variables. RESULTS: There were considerable differences in the utilisation of CVD drugs within the districts studied. Significantly higher utilisation of dihydropyridine Ca-channel blockers and statins was found in the districts with a higher percentage of university-educated inhabitants and more ambulatory physicians. CVD drug utilisation (nitrates, fibrates, selective beta-blockers, verapamil and diltiazem and statins) correlated significantly with the percentage of single-member households. The five socio-economic variables explained more than 60% of the variability in use of dihydropyridine Ca-channel blockers, verapamil and diltiazem, ACE inhibitors and statins. CONCLUSION: There exists a significant gradient in the utilisation of mainly newer CVD drug groups within districts of the Czech Republic that can be, at least partly, explained by social characteristics of the districts.

Cardiovascular Agents↗

Antidepressant drug prescribing in Italy, 2000: analysis of a general practice database.

OBJECTIVE: Databases of subjects receiving antidepressants provide evidence on the use of drugs in typical patients and settings under real-world conditions. This study analysed a general practice database to estimate the prevalence of antidepressant drug use, describe the use of these compounds by gender and age and estimate the prevalence of occasional versus non-occasional users. METHODS: The general practice database of Chivasso, a city near Turin in Piedmont, was analysed. The database includes all community (i.e. outside hospitals) prescriptions reimbursed by the National Health System in the population living in the study area. From the database, the total number of units of antidepressant drugs prescribed over a 6-month period was extracted. Using the general practice patient code, all records were converted into a sample of patients receiving one or more prescriptions of one or more antidepressants. RESULTS: During the 6 months surveyed, 12,930 antidepressant prescriptions were dispensed to 3751 patients, resulting in a prevalence of use of 19 patients per 1000 inhabitants (confidence interval 18.3, 19.5). The prevalence of use progressively increased with age and was more than double in females than males (female/male ratio 2.16). Paroxetine was the most prescribed compound, followed by amitriptyline and fluoxetine. However, in older subjects, the top two antidepressants were trazodone and amitriptyline. Nearly one-fourth of all dispensed antidepressants were prescribed on one occasion only; occasional users were slightly younger than non-occasional users. CONCLUSIONS: In Italy, databases have been used to monitor the prescription of medicines, but they have always provided aggregate data on drug sales and consumption. In this study, a sample of typical patients receiving antidepressants under real-world conditions was analysed to help clarify what happens in clinical practice. Databases of patients receiving antidepressants should be adopted to suggest public health priorities and generate original research hypotheses to be formally tested with experimental studies.

Adolescent↗