Decline in US stroke mortality: an analysis of temporal patterns by sex, race, and geographic region

BACKGROUND AND PURPOSE

Although stroke mortality rates have declined rapidly over the past 30 years, the decline has slowed to a plateau. Here, we assess whether the race-sex-region groups have participated equally in this decline and whether there are groups in which stroke mortality rates are still declining, and we predict how these rates will eventually differ.

METHODS

Data on stroke mortality in the United States between 1968 and 1996 were analyzed in a 3-step procedure: (1) we calculated "crude" age-adjusted stroke mortality rates by race, sex, and county; (2) we "smoothed" the rates across counties and years; and (3) we fit a model to describe the temporal pattern. From this model we calculated the percent decline in stroke mortality, the anticipated additional decline (thereby identifying regions that will continue to decline), and the anticipated eventual stroke mortality rates.

RESULTS

Maps by race-sex-region group describe the above parameters. White men have experienced the largest decline in stroke mortality, and black men have seen the smallest. Generally, stroke mortality appears to still be slowly declining for blacks but not for whites. Geographic differences in stroke mortality are predicted to persist.

CONCLUSIONS

The analysis suggests that the Deep South (Alabama and Mississippi) will fall from the stroke belt and be replaced by other regions (notably Oregon, Washington, and Arkansas). New York City and southern Florida had low stroke mortality rates in 1968, have experienced large declines, and continue to experience declines, resulting in even larger relative heterogeneity of stroke mortality rates. The reasons for these differences in the pattern of the decline in stroke mortality are not understood.

Resident physician management of Hispanic and non-Hispanic white patients on antidepressants

OBJECTIVE

The purpose of this study was to examine how well resident physicians monitored Hispanic and non-Hispanic white patients who were prescribed antidepressant medication.

METHOD

Retrospective and prospective review of patients' medical records.

SETTING

Family practice and internal medicine clinics at the University of New Mexico Health Sciences Center.

PARTICIPANTS

Twenty-six resident physicians and 109 of their Hispanic and non-Hispanic white patients who were prescribed antidepressant medication when recruited into the study between March and December 1995.

MAIN OUTCOME MEASURES

(i) Whether a physician recorded an appropriate diagnosis in the patient's chart, scheduled a follow-up visit and saw the patient for a follow-up visit within four weeks of the antidepressant being prescribed, and (ii) whether a physician recorded an adequate treatment plan, a discussion of side-effects and a discussion of how well the medication was working on the date the patient was enrolled in the study.

RESULTS

Twenty-seven percent of patients were prescribed antidepressant medication. Less than half of the patients who were prescribed an antidepressant had a follow-up visit scheduled and only about one-third of patients were seen by their physician within one month of the antidepressant being prescribed. Physicians documented an adequate treatment plan in the charts of 51.1% of patients, a discussion of side-effects in 11.1% of charts and an assessment of how well the medication was working in 33.3% of charts. Younger patients and patients in better emotional health were more likely to have an adequate treatment plan documented in their chart. Patients in poorer physical health were more likely to have an adequate treatment plan documented in their chart along with a description of the effectiveness of the medication. Hispanic and non-Hispanic white patients who were prescribed antidepressants were monitored equally well by their primary care physicians.

CONCLUSION

Primary care resident physicians need further training on the importance of monitoring patients on antidepressant medication.

Physician gender and hormone replacement therapy discussion

Hormone replacement therapy (HRT) is a major issue confronting millions of women today, and general internal medicine and family practice physicians are an important source of information and counseling on this issue. Previous studies have suggested that HRT discussion and prescribing are more frequent with female than with male physicians, but others have suggested age and practice setting may be the reason for observed differences. We attempted to determine if physician gender influenced HRT discussion frequency between physicians and their patients using cross-sectional, secondary analysis of data collected at general internal medicine and family practice clinics at the University of New Mexico Health Sciences Center. Twenty-seven family practice and internal medicine resident physicians (15 female, 12 male) participated. There were 127 female patients age 45 and older. Audio-taped observations of patient-physician visits collected during 1995 for a study on patient-physician communication and patient satisfaction were used. There was less frequent discussion with female than male physicians (OR = 0.42, p = 0.0014). HRT was discussed during 51 visits. Patients initiated HRT discussion in 39.2% of visits in which it was discussed. Patients with diabetes were less likely to discuss HRT (OR = 0.25, p = 0.0122). Increasing year of physician residency was associated with decreased discussion of HRT (OR = 0.51, p < 0.0001). In this health sciences center, with physicians similar in age and training, male physicians discussed HRT significantly more often than did female physicians.

Correlation between varying levels of PMP22 expression and the degree of demyelination and reduction in nerve conduction velocity in transgenic mice

Charcot-Marie-Tooth disease type 1A is most commonly caused by a duplication of a 1.5 Mb region of chromosome 17 which includes the peripheral myelin protein 22 gene (PMP22). Over-expression of this gene leads to a hypomyelinating/demyelinating neuropathy and to severely reduced nerve conduction velocity. Previous mouse and rat models have had relatively high levels of expression of the mouse or human PMP22 gene leading to severe demyelination. Here we describe five lines of transgenic mice carrying increasing copies of the human PMP22 gene (one to seven) and expressing increasing levels of the transgene. From histological and electrophysiological observations there appears to be a threshold below which expression of PMP22 has virtually no effect; below a ratio of human/mouse mRNA expression of approximately 0.8, little effect is observed. Between a ratio of 0.8 and 1.5, histological and nerve conduction velocity abnormalities are observed, but there are no behavioural signs of neuropathy. An expression ratio >1.5 leads to a severe neuropathy. A second observation concerns the histology of the different lines; the level of expression does not affect the type of demyelination, but influences the severity of involvement.

Mitochondrial versus nuclear admixture estimates demonstrate a past history of directional mating

Six blood group antigens (ABO, RH, MNS, KK, KP, FY) and five plasma proteins (HP, GC, APOA4, FXIIIB, C1R) were typed in 790 individuals, and 12 mtDNA RFLP and deletion polymorphisms were typed in 657 individuals from the San Luis Valley, Colorado. The 790 nuclear typings were conducted on 399 Anglos and 391 Hispanics, while the 657 mitochondrial haplotypes were generated from 207 Anglos and 450 Hispanics. Chakraborty's ADMIX2 FORTRAN program was used to estimate the average Amerindian admixture using all nuclear loci simultaneously. Since there is no recombination in mtDNA, the sum of the frequencies of the Amerindian/Asian-specific mitochondrial haplotypes represents the level of Amerindian admixture. The nuclear estimates of Amerindian admixture were 33.15 +/- 2.41% for the Hispanics and 9.72 +/- 1.90% for the Anglos, while the strictly maternally inherited mtDNA estimates of Amerindian admixture were 85.11% for the Hispanics and 0.97% for the Anglos. This dramatic difference in estimated levels of admixture between the biparentally derived nuclear estimates and the uniparentally derived mtDNA estimates is indicative of past directional matings between Hispanic males and Amerindian females.

Linkage analysis in a family with the Opitz GBBB syndrome refines the location of the gene in Xp22 to a 4 cM region

The Opitz GBBB syndrome (OS) is characterized in part by widely spaced inner ocular canthi and hypospadias. Recently, linkage analysis showed that the gene for the X-linked form to be located in an 18 cM region spanning Xp22. We have now conducted linkage analysis in a family previously published as having the BBB syndrome and found tight linkage to DXS7104 (Z = 3.3, theta = 0.0). Our data narrows the candidate region to 4 cM and should facilitate the identification and characterization of one of the genes involved in midline development.

A mutation in the interferon-gamma-receptor gene and susceptibility to mycobacterial infection

BACKGROUND

Genetic differences in immune responses may affect susceptibility to mycobacterial infection, but no specific genes have been implicated in humans. We studied four children who had an unexplained genetic susceptibility to mycobacterial infection and who appeared to have inherited the same recessive mutation from a common ancestor.

METHODS

We used microsatellite analysis, immunofluorescence studies, and sequence analysis to study the affected patients, unaffected family members, and normal controls.

RESULTS

A genome search using microsatellite markers identified a region on chromosome 6q in which the affected children were all homozygous for eight markers. The gene for interferon-gamma receptor 1 maps to this region. Immunofluorescence studies showed that the receptor was absent on leukocytes from the affected children. Sequence analysis of complementary DNA for the gene for interferon-gamma receptor 1 revealed a point mutation at nucleotide 395 that introduces a stop codon and results in a truncated protein that lacks the transmembrane and cytoplasmic domains.

CONCLUSIONS

Four children with severe mycobacterial infections had a mutation in the gene for interferon-gamma receptor 1 that leads to the absence of receptors on cell surfaces and a functional defect in the up-regulation of tumor necrosis factor alpha by macrophages in response to interferon-gamma. The interferon-gamma pathway is important in the response to intracellular pathogens such as mycobacteria.

Intra- and Interpopulation Genome Variation In Meloidogyne arenaria

The genetic heterogeneity of two M. arenaria race 2 populations (designated Pelion and Govan) was examined using RFLP analysis of 12 clonal lines established from single egg masses (six distinct clonal lines from each population). These populations are essentially identical by traditional biochemical and race identification schemes; however, the Govan population is more aggressive than the Pelion population, producing larger galls and exhibiting greater reproductive capabilities on many soybean cultivars and experimental accessions. Variation at the genomic DNA level was examined using probes representative of expressed DNA sequences present in the eukaryotic genome. Ribosomal DNA, interspersed repeated sequences, and cDNA probes were tested for detection of polymorphism within and between single egg mass lines of each population. Cloned cDNAs and ribosomal intergenic spacer sequences detect polymorphism both within and between populations, demonstrating the usefulness of these sequence classes for molecular genetic analysis of population structure and genome evolution.